DIE FERRITISCHE LÖSUNG

Co-edited by ISSF and ICDA

The Ferritic Solution – Translation

The Ferritic Solution

Properties

Advantages

Applications

The essential guide to ferritic stainless steels



International Stainless Steel Forum (ISSF)


Founded in 1996, the International Stainless Steel Forum (ISSF) is a
non-profit research organisation that serves as the world forum on
various aspects of the international stainless steel industry. Whilst
having its own Board of Directors, budgets and Secretary General,
ISSF is part of the International Iron and Steel Institute (IISI). ISSF
now comprises some 67 company and affiliated members in 24
countries. Jointly, they are responsible for around 85 percent of
worldwide stainless steel production. A full list of members can be
found on the ISSF website: www.worldstainless.org.


Contents


Appendices:





P 4
STRUCTURAL STEELWORK FOR HIGHWAY BRIDGE IN DURBAN,
SOUTH AFRICA, OF PAINTED FERRITIC STAINLESS STEEL.





P 5
Summary


THE FERRITIC SOLUTION


BY JEAN-YVES GILET, CHAIRMAN OF THE ISSF MARKET
DEVELOPMENT COMMITTEE


ISSF first discussed a project to promote ferritic grades in February
2004, many members having pointed out that no joint industry effort
was being made in this direction.


Under the guidance of the Market Development Committee, an
international group of experts, led by Philippe Richard, started by
gathering market statistics on ferritic grades and applications. They
received contributions from all around the world – especially Japan,
where the ferritics market is the most developed.


The ICDA soon proposed to join the initiative and cofund the project.
This we accepted with great pleasure, as a concrete example of
cooperation between international business organisations.


During the project’s start-up phase, nickel prices hit the roof and
interest in more price-stable grades increased dramatically. ISSF then
gave the project highest priority! I am now proud to present the
results, which will ‘hit the market’ at just the right time.


I strongly believe that ferritic stainless steels can and should be much
more widely used. The purpose of this publication is to bring about
more extensive use of these grades.


Stainless steels are ‘stainless’ because their chromium content gives
them remarkable resistance to corrosion. Ferritic grades, containing
only chromium and possibly other elements (Mo, Ti, Nb, etc.), are no
exception. Wellknown standard ferritic grades 409, 410 and 430 are
readily available all over the world. Very successfully used in
important applications, such as washing-machine drums and exhaust
systems, they actually have much broader application potential, in
numerous fields.


More recently-developed ferritic grades, such as 439 and 441 meet an
even broader range of requirements. They can be formed to more
complex shapes and joined using most conventional joining methods,
including welding. Thanks to the addition of molybdenum, the
resistance of ferritic grade 444 to localised corrosion is at least equal
to that of austenitic grade 316.


Since ferritic grades do not contain nickel, their cost is lower and more
stable than that of austenitic stainless steels. they can therefore:


complement type 304 within the stainless steel family (although 304
remains a versatile and commonly used grade);


be an alternative to the 200 series (offering generally better usage
properties);


substitute for other materials in many areas (e.g. carbon steel, Cu, Zn,
Al, plastic, etc.), thanks to their special technical properties – the
drivers for replacement being, usually, technical and life cycle cost
benefits.


Ferritic stainless steels’ magnetism is not a ‘negative’ quality
somehow associating it with ordinary carbon steel. On the contrary,
magnetism is a special asset of these excellent stainless steels,
marking them out from other stainless steel grades.


To get the best results from ferritics, it is essential that:


new users be trained in forming and joining techniques;


the user consult his stainless steel producer regarding correct grade
selection;


the user acquire his material from a reliable source, able to offer
proven guarantees as to the grade, quality and origin of the material
supplied.


The high quality of the team’s efforts and the strong support of the
ICDA allow us today to present a reference document for our stainless
steel business. It benefits from highly interesting testimonials from
customers, showing a lively interest in new developments. ISSF is
grateful for all these contributions.





P 6
Foreword


A STEEL WHOSE TIME HAS COME


By Friedrich Teroerde of the International Chromium Development
Association


I must first thank ISSF for inviting the ICDA to write the foreword to the
ferritic Solution – a publication that is inevitably eloquent on the
subject of chromium.


The ICDA was set up in Paris, in 1990, and currently boasts some 96
members from 26 countries across 5 continents. Our mission is to tell
the world the positive story of chromium.


Chromium is used in iron and steel to produce stainless steel and
other alloys. In stainless steel, chromium is a special ingredient. It is
the alloying element that makes stainless steel “stainless”, giving it its
remarkable corrosion and oxidation resistance. Chromium is both
readily available and easily recycled in its stainless steel form, posing
no threat to the environment.


As a body representing the chromium producers, we are sponsoring
this handbook because we believe it will develop the chromium
industry. Chromium is never used alone. The Market Development
Committee of ICDA has therefore been implementing projects of
common interest with sister organisations like ISSF for some years.
Chromium is the basic element of all families of stainless steel – at an
average content level of 18 percent. The annual consumption of
stainless steel is increasing at a compound growth rate of 5 percent
and the material is used in an increasing number of applications in the
food, beverage, mining and automotive industries and in architecture.


You will be aware that nickel, used in “austenitic” stainless steels is
subject to considerable price fluctuations, due to stock market factors.
In fact, in the last few years, the nickel price has increased to
unprecedented levels, greatly affecting the cost of austenitic grades.


Ferritics, the second great family of stainless steels, contain no nickel.
They do, however, contain chromium. In the context of our own
development, given the exceptional growth in the stainless steel
market, we feel we should strongly encourage the broader use of
ferritic grades, at this time.


We were therefore delighted when ISSF asked us to support its
project to identify and develop new ferritic market applications. The
admirable aim of this project is to achieve sustainable growth in the
stainless steel market and build a bright future for these excellent
grades.


Looking at information already available on ferritic grades, one finds
plenty of material on stainless steel in general but little dedicated
specifically to ferritics – although such grades have existed for almost
100 years! This lack has encouraged ISSF to create the current
handbook. It provides essential information on the technical
properties, advantages and potential applications of ferritic grades and
gives fabrication recommendations. It also attempts to correct certain
popular misconceptions regarding the use and characteristics of
ferritic stainless steels.


In conclusion, ICDA is aware that the volatility of nickel presents a
major problem for stainless steel users. We are keen to support the
industry and its customers by participating in the search for alternative
solutions. It is clear to us that, thanks to its proven technical qualities
and cost advantages, ferritic stainless steel is a steel whose time has
come.


The following pages will guide existing and potential stainless steel
users in extending the use of ferritic grades into new and exciting
application areas.


Friedrich Teroerde
Chairman
Market Development Committee
ICDA





P 7
FERRITIC STAINLESS STEEL IS IDEAL FOR THE EXTERNAL
SURFACES OF PROFESSIONAL KITCHEN EQUIPMENT.





P 8
THE SHINING APPEARANCE OF FERRITIC IS A SYMBOL OF
CLEANLINESS AND HYGIENE IN FOOD-CONTACT
APPLICATIONS.





P 9
What they’re saying about ferritics


The economic advantages and technical merits of ferritic grades have
been appreciated by certain market sectors for a number of years.
The following testimonials, representing both existing and evolving
markets, show that these benefits are becoming more widely
understood.




STEFAN RAAB


DIRECTOR CORPORATE PURCHASING OF PRODUCT
MATERIALS, BSH BOSCH UND SIEMENS HAUSGERATE GMBH,
MUNICH, GERMANY


“We use stainless steel in about a third of our products. Our reason for
using this material is partly functional, because of its corrosion
resistance, and partly aesthetic. The share of ferritic stainless steel is
approximately 50 percent at this time. Our intention is to increase this,
mainly because ferritic gives the customer the benefits of stainless
steel in terms of functional qualities and design, in many application
areas, but within a limited cost frame. We will use ferritic grades
wherever corrosion resistance and formability allow.”




ROBERTA BERNASCONI


MANAGER, GLOBAL TECHNOLOGY – MATERIALS, WHIRLPOOL
CORPORATION, CASSINETTA DI BIANDRONNO, ITALY


“As a manufacturer of home appliances, we use ferritics for our
refrigerators and washing machines and are evaluating conversion to
ferritics for cooking appliances and dishwashers. The cost advantage
is such that it makes sense for us and our customers that we should
make more use of these grades.


“We accordingly design our products with the necessary
manufacturing considerations in mind and occasionally select a
coated grade and even a fingerprint-protected coated grade, if need
be, to ensure long service life. We may, on occasion, use a higher-
alloyed ferritic grade. The important thing is to benefit from the
economic advantages of using ferritics.


“We find them excellent for our applications and, given the high cost of
nickel, the future, in our case, definitely lies with these excellent
steels.”




JEAN-LOUIS LALBA


MARKET BUYER FOR GROUPE SEB, (TEFAL, ROWENTA, KRUPS,
MOULINEX, ARNO, ALL CLAD, PANEX, ETC.), RUMILLY, FRANCE


We use about 15,000 metric tons of stainless a year, of which some
40 percent is ferritic. Our group originally used ferritics for cookware
lids, for which they are ideal, for the stamped or brazed bases of
induction cookware and for oven housings. This has extended to
include frying pans, in those cases where the result is entirely
satisfactory for the end-user.


“Often, in such applications, the corrosion resistance, deep drawing
and polishing characteristics of ferritics have proved very acceptable
both for us and our customers. There are cases where very
demanding manufacturing or in-service requirements will exceed the
limits of ferritic grades, in terms of one or more of these qualities or in
terms of ease of processing. And there is even irrational prejudice
against ferritics in some countries! However, we find these grades to
be a perfect choice in many instances. Indeed, their magnetic nature
is essential to stainless steel induction cookware. And, of course, the
price of ferritics is stable and reliable.


“Given our good experience of ferritics, we intend to extend their use
to other applications.”





P 10
IN THE SUGAR INDUSTRY, FERRITIC STAINLESS STEEL HAS
PROVED SUPERIOR TO CARBON STEEL ON EVERY LEVEL.





P 11
GAETANO RONCHI


SENIOR MANAGER, METALS PROCUREMENT, IKEA


“We use stainless steel for pots & pans, cutlery – including knives –
and bathroom and kitchen accessories. Our current annual
consumption, of 60,000 tons a year, is growing by about 15 percent a
year. A substantial part of this is ferritic.


“In mid-2003, IKEA decided to adopt ferritic grades as general-
purpose stainless steels, largely due to the material’s stable,
predictable price. Tests showed that articles with welded seams
require a grade with higher chrome content than standard 430 for
optimum corrosion resistance and that welded components need
further processing to meet requirements. However, the decision
represented a breakthrough for our development of stainless steel
articles. Our sales growth and the use of stainless steel in new-
product design would have been seriously jeopardised had we stayed
with austenitic grades.


“A significant number of IKEA’S stainless steel articles are
manufactured by an Asian OEM and the success of our transition to
ferritics has been due to educating and training the group’s purchase
offices in Asia and its OEM subcontractors. Our target is to phase out
austenitic grades completely, replacing them with upgraded ferritics.
We are currently testing new ferritic grades with enhanced
deepdrawing or corrosion-resistance properties.”




MICHAEL LEUNG


ASSISTANT MANAGER,
YIU HENG INTERNATIONAL COMPANY LIMITED, MACAO


“The main products of our subsidiary Xinhui Rixing Stainless Steel
Products, based in Guangdong province, china, are stainless steel
cookware and kitchen utensils. At the time of writing, the company
consumes about 800 metric tons of stainless steel per month, of which
66-70 percent is ferritic. When we launched our factory, in 1999, we
just used 400-series grades on the bottom of cookware. We began
using them for cookware bodies in 2002.


“Low cost is not the only reason for favouring ferritics. Ferritic grades
are magnetic and have good thermal conductivity. They are easy to
recycle, which helps save the planet’s resources. Changing from 304
to ferritic means that the manufacturer becomes more competitive and
the consumer gets a safe product at a lower price. We must correct
the unfounded prejudice that because ferritics are magnetic they are
lowquality and have poor corrosion resistance.


“In factories where 304 is predominantly used, changing to ferritic
grades means adjusting the manufacturing process and dies. This is
costly. Our experience, however, shows that total production costs
can be lowered with ferritics.


“Overall, we are very satisfied with ferritics. A good range of ferritic
grades has been developed, to meet a wide variety of requirements.
We hope ferritic stainless steel becomes widely available in steel
service centres and becomes more extensively used in a broad range
of sectors.”




ATUSHI OKAMOTO


MANAGER OF NO.1 PRODUCTION SECTION, OSAKA WORKS,
TAKARA STANDARD CORP., JAPAN


“Takara Standard is a major Japanese manufacturer of kitchen and
bathroom products. We use stainless steel for sinks and top panels of
built-in kitchens and for bathtubs and mounting components of built-in
baths. This company has used ferritic grades for about 40 years, for
the simple reason that their properties are sufficient for these
applications.


“We are successful with ferritics because our product design takes
into account the specific mechanical properties of these grades and
we have appropriate press-forming and die technology. We have met
no major problems with ferritic grades. When an intricate shape is
required, we carry out trials, to establish the best processing
parameters.


“To conclude, we are very satisfied with ferritic stainless steels. I
would like to see guidelines issued to help companies choose the right
ferritic grade for their application.”




OTHER TESTIMONIALS FOLLOW ON THE LEFT-HAND PAGES
BEFORE EACH CHAPTER...





P 12
FERRITIC STAINLESS STEEL WELDED TUBES HAVE A DYNAMIC
FUTURE IN THE TUBE MARKET, DUE TO THE TECHNICAL AND
ECONOMIC MERITS OF THESE GRADES.


CLOVIS TRAMONTINA


PRESIDENT, TRAMONTINA, SÃO PAULO, BRAZIL.


“As a major Brazilian manufacturer of household goods and tools, with
an intense export activity, Tramontina currently uses about 850 tons of
stainless steel per month, of which almost 30 percent is ferritic. The
products for which we mainly use ferritics are economical trays and
cutlery, sinks and the base of pans.


“We have used ferritics since 1974, when we started to produce pans
and serving sets at our plant in Farroupilha. Our main reason for
introducing ferritics was the lower cost of this raw material, coupled
with the fact that their characteristics and properties are very
satisfactory for these applications.


“In terms of deep-item manufacturing, such as lay-on sinks, ferritics
are not as easy to work with as austenitics and require an
intermediate rolling process. However, I still consider ferritic stainless
steel as a good choice, due to the cost/benefit ratio. Being easy to
clean and maintain, the material is hygienic. It also has all the
aesthetic merits of stainless steels and is available in various surface
finishes.


“To sum up, we’re happy with ferritics and have used them for a long
time now. In fact, we’re always looking for new applications in which to
use them and benefit from the cost advantage.”



P 13
The “fabulous ferritics”


In the face of an explosion in raw-material costs, ferritic stainless
steels are emerging as a useful solution in many applications where
cost-saving material substitution has become an imperative.


In recent years, prices of raw materials such as aluminium, copper,
zinc and nickel have exploded. Stainless steel producers and users,
notably, are greatly affected by the high and volatile nickel price –
which fluctuates daily. Nickel is a constituent of the widely used
“austenitic” (300-series) stainless steel grades.


Stainless steel producers have no control over these phenomena,
whose inevitable effect is to both push up and destabilize the cost of
their nickel-containing grades. This situation is forcing some existing
users of these grades to seek materials that cost less than austenitics
but which might still provide fabrication and in-service characteristics
adequate for their product or application.


The situation can also scare off potential users of stainless steel, who
may believe that stainless steels possessing the qualities they need
are financially out of reach.




LOWER COST, STABLE PRICE


The good news is that ferritic (400-series) stainless steel grades – low
and stable in price yet boasting impressive technical characteristics –
are waiting in the wings, ready to prove an excellent alternative
material for many supposedly “austenitic-only” applications.


Containing no nickel, ferritic grades basically consist of iron and
chromium (min. 10.5%). The price of chromium – the ingredient that
makes “stainless” steel especially corrosion resistant – is historically
relatively stable. Certain ferritic grades contain additional alloying
elements, such as molybdenum, to enhance specific properties.


Ferritic stainless steels share most of the mechanical and corrosion-
resistance properties of their more expensive cousins, the austenitics,
and even improve on austenitics in certain characteristics. Why pay
for nickel if you don’t have to?


Users of copper, aluminium or austenitic stainless steels in search of
another solution can take heart. Ferritics are often an affordable and
technically ideal way to benefit fully from stainless steel’s unique
qualities.




“Why pay for nickel if you don’t have to?”



P 13 tables and pictures
LME CASH NICKEL PRICE 1999-2007 (US $/T)




Professional griddle, in grade 430.




Canopy, in grade 446M, S. Korea.





P 14
THE 5 FERRITIC “FAMILIES”


Ferritic grades fall into five groups – three families of standard grades
and two of “special” grades. By far the greatest current use of ferritics,
both in terms of tonnage and number of applications, centres around
the standard grades. Standard ferritic stainless steels are plainly,
therefore, totally satisfactory and entirely appropriate for many
demanding applications.


Group 1 (type 409/410L) has the lowest chromium content of all
stainless steels and is also the least expensive. This group can be
ideal for non- or lightly-corrosive environments or applications where
slight localised rust is acceptable. Type 409 was originally designed
for automotive exhaustsystem silencers (exterior parts in non-severe
corrosive environments). Type 410l is often used for containers, buses
and coaches and, recently, LCD monitor frames.


“Standard ferritic stainless steels are totally satisfactory and entirely
appropriate for many demanding applications.”


Group 2 (type 430) is the most widely used family of ferritic alloys.
Having a higher chromium content, group 2 grades show greater
resistance to corrosion and behave most like austenitic grade 304. In
some applications, these grades are suitable to replace type 304 and
are usually of high enough grade for indoor applications. Typical uses
include washing-machine drums, indoor panels, etc. Type 430 is often
substituted for type 304 in household utensils, dishwashers, pots and
pans. For information on its welding characteristics, see p. 37 et seq.


Group 3 includes types 430Ti, 439, 441, etc. Compared with group 2,
these grades show better weldability and formability. Their behaviour
is even, in most cases, better than that of 304 austenitic grades.
Typical applications include sinks, exchanger tubes (the sugar
industry, energy, etc.), exhaust systems (longer life than with type
409) and the welded parts of washing machines. Group 3 grades can
even replace type 304 in applications where this grade is an over-
specification.



P14 tables and pictures
STANDARD FERRITIC GRADES


~ 91% of total volume in 2006


Group 1


10%-14%


30%


Types 409, 410, 420
Cr content: 10%-14%


Group 2


14%-18%


48%


Type 430
Cr content: 14%-18%


Group 3


14%-18%
stabilised


13%


Types 430Ti, 439, 441, etc.
Cr content: 14%-18%.
Include stabilising elements such as Ti, Nb, etc.




Containers, in grades 409L and 410L.




SPECIAL FERRITIC GRADES


~ 9% of volume in 2006


Group 4


Added Mo


7%


Types 434, 436, 444, etc.
Mo content above 0.5%


Group 5


Others


2%


Cr content: 18%-30%
or not belonging to the other groups





P 15
Group 4 includes types 434, 436, 444, etc. These grades have added
molybdenum, for extra corrosion resistance. Typical applications
include hot water tanks, solar water heaters, visible parts of exhaust
systems, electric kettle and microwave oven elements, automotive
trim and outdoor panels, etc. Type 444’s corrosion-resistance level
can be similar to that of type 316.


Group 5 (types 446, 445/447 etc.) Has additional chromium and
contains molybdenum, for extra corrosion and scaling (oxidation)
resistance. This grade is superior to type 316 in respect of these
properties. Typical uses include applications in coastal and other
highly corrosive environments. The corrosion resistance of JIS 447 is
equal to that of titanium metal.




IMPRESSIVE REFERENCES


Among the success stories of ferritic stainless steels, two typical and
extremely demanding applications stand out. For years, ferritic grades
have been very extensively used in two extremely demanding
applications: automotive exhaust systems and washing-machine
drums.


Exhaust systems are exposed to high temperatures and corrosive
environmental conditions. The use of stainless steel (ferritic) makes it
possible to extend the warranty period of these parts.


Washing-machine drums have to withstand detergents and a virtually
constantly humid environment. In this context, however, localised
corrosion would be utterly inadmissible.


Car owners and householders will readily testify to their satisfaction
with the long life of their washing-machine drums and exhaust
systems. For manufacturers of these products, “fabrication
friendliness” and major economic advantages are additional factors
making ferritic stainless steel the obvious choice.




“…In many cases, ferritics are emerging as a better choice than more
expensive materials.”




Other current uses of ferritic grades range from kitchenware and
catering equipment to indoor furniture and decorative items,
automotive trim, superheater and reheater tubes, burners, air-
conditioning ducts, barbecue grills, etc. Many new applications are
waiting to emerge.




TODAY’S EXCELLENT FERRITICS


Top-quality ferritic stainless steels have existed for some years now
and much intensive research and development has gone into defining
the remarkable grades currently available.


They are neither new to the market nor to their highly experienced
producers. Strangely, though, attitudes to these steels seem tinged
with misconception and ignorance, for largely historical reasons.
Grade 430 was once the only grade available and early, pioneering
users may have received insufficient technical support regarding the
use of this grade – especially, perhaps, in the case of welded
structures or more corrosive conditions. In any event, the false idea
took hold, in some quarters, that ferritics are “inferior” and that only
austenitics will do.


Ferritics moved on a long time ago! Full technical support is available
today and the range of grades has greatly increased and diversified,
to meet users’ needs, in terms of properties. Since these properties
are broadly comparable to those of austenitics, it is wrong to see
ferritic grades as either inferior or superior. They are just different –
and usefully so.



P 15 pictures
Solar water heater, Taiwan, China.




Overpass noise-absorbing plate, Japan.





P 16
Indeed, in many cases, ferritics are emerging as a better choice than
more expensive materials. They may more closely match the actual
specification of a particular application, providing just the qualities
needed – no less and, equally importantly, no more.




FINE FOR FORMING


Every bit as malleable as carbon steel, ferritic grades are suitable for
most forming operations. They are less malleable than austenitic
stainless steels, which have exceptional properties, but in many cases
austenitics are “over-specified”.


Carbon steel and ferritic stainless steel demonstrate equivalent
forming behaviour. One need only think, therefore, of the complex
shapes into which carbon steel is currently formed (e.g. Car bodies) to
appreciate the broad possibilities for ferritic stainless steels. Given
correct adaptation of tooling and choice of grade, countless shapes
may be formed using ferritic grades.




PROUD TO BE MAGNETIC


A widely held misconception is that because ferritics are magnetic
they are not “real” stainless steels and will rust like carbon steel. This
is nonsense. Purely for reasons of atomic structure, some stainless
steels are magnetic and some are not. Corrosion resistance is not a
matter of atomic structure but one of chemical composition – in
particular chromium content. Magnetism has nothing to do with it.


In fact, the magnetism of ferritic grades is one of the material’s major
assets, having many existing and potential uses and advantages,
ranging from sticking memos on the fridge to storing knives and other
metallic implements. Indeed, it is essential that pans used in
“induction” cooking are magnetic, since the process involves
generating heat in the cookware itself by transfer of magnetic energy.




SPECIAL TECHNICAL ADVANTAGES


Stainless steel is an especially durable, low-maintenance material,
with considerable life cycle cost advantages over carbon steel. It is
also 100% recyclable: over 60% of new stainless steel is made from
melted scrap.


Stainless steel’s main properties can be summarised as follows:


? corrosion resistance
? aesthetic appeal
? heat resistance
? low lifecycle cost
? full recyclability
? biological neutrality (meets EU RoHS requirements)
? ease of fabrication


Ferritic stainless steels boast all the advantages that stainless steels
have over carbon steels in terms of corrosion resistance, low life cycle
cost and longevity. In addition, their advantages over their close
cousins, the austenitic grades, do not just stop at costing less.
Ferritics actually outshine austenitics in several characteristics.




“A widely held misconception is that because ferritics are magnetic
they are not “real” stainless steels and will rust like carbon steel. This
is nonsense.”



P 16 pictures
Milk tanker, cladding in grade 430, S. Africa.




Refrigerator, cladding in grade 430.





P 17
FERRITIC SPECIAL TRUMP CARDS


Ferritics are magnetic.


Ferritics have low thermal expansion (they expand less than
austenitics when heated).


Ferritics have excellent high-temperature oxidation resistance (they
are less prone to scaling than austenitics).


Ferritics have high thermal conductivity (they conduct heat more
evenly than austenitics).


Ferritics stabilised with niobium have excellent creep resistance (they
deform less than austenitics in response to long-term stresses).


Ferritics are easier to cut and work than austenitics (which require
special tools and more powerful machines and generate greater
tooling wear).


Ferritics are significantly less prone to springback than austenitics,
during cold forming.


Ferritics have higher yield strength (similar to that of popular carbon
steels) than type 304 austenitics.


Ferritics, unlike austenitics, are not prone to stress corrosion cracking.




P 18
PERFECTION IS MATCHING THE SPEC


In current market conditions, existing and potential users should,
above all, avoid “over-specifying” when choosing a steel for a given
application.


Historically, austenitic grade 304 has been the most widely developed
and readily available stainless steel grade, due to the broad spectrum
of applications for which it is suitable. Today’s ferritic stainless steel
grades, properly specified, can often be substituted for 304, to
excellent effect.


Close and realistic examination of the fabricating and in-service
qualities required will often reveal that an economically advantageous
ferritic grade can perfectly adequately meet these specifications, for
both fabricator and end-user.


Sometimes, a reasonable in-service compromise (e.g. Advising end-
users to clean their product’s surface regularly) is all that is required to
keep a particularly inexpensive ferritic grade immaculately corrosion-
free for the life of the product.




“A STEEL WHOSE TIME HAS COME”


given the quality of today’s ferritic grades, their price advantage and
the exceptional properties that can be obtained by using additional
alloying elements, the opportunities for ferritic stainless steels seem
unlimited.


This brochure tries to make the qualities of ferritics easily
understandable, describing them in relatively simple terms. Its aim is
to encourage the greater use of stainless steels in general by
increasing awareness of the merits of these lower-cost grades. This is
part of a stainless steel industry initiative to help users specify the
correct grades for their application.


The following pages examine the properties of today’s ferritics, the
roles of the various alloying elements and the many existing and
potential applications of these steels.




“Today’s ferritic stainless steel grades, properly specified, can often be
substituted for 304, to excellent effect.”



P 18 pictures
Kitchen line-up, in grade 430, S. Africa.




Cladding panels, in coated grade 430, Italy.




P 19
IN CERTAIN ENVIRONMENTS FERRITIC STAINLESS STEELS
PROVIDE AN AESTHETIC, DURABLE AND ECONOMICAL
SOLUTION FOR URBAN FURNITURE REQUIREMENTS.




P 20
DOMINIQUE MARET


MARKETING DIRECTOR, FAURECIA EXHAUST SYSTEMS,
FRANCE


“As a worldwide automobile equipment supplier, Faurecia’s main use
of stainless steels is in exhaust systems. Of the 200,000 metric tons or
so of stainless steel that we use for this purpose annually, some 90
percent is ferritic. In fact, we’ve been using ferritics since the mid-
1970’s, when we started producing catalytic converters conforming to
U.S. Emission standards. Ferritics have much lower thermal
expansion characteristics than austenitics, which was a crucial factor
in the durability of these catalytic converters.


“Ferritics are a success story for us because our deep understanding
of the specific behaviour of the grades in different exhaust
environments means we can choose the right grade for the right
application. Of course, formability limitations and the need to avoid
intergranular corrosion need to be taken into account in both product
design and manufacturing process. We increasingly require continued
progress with ferritics in the areas of high temperature performance
above 900°c and corrosion resistance. We believe that such
improvements to ferritic grades will bring them closer to the
performance of austenitics, but still at a lower and more stable cost.
That said, we’re already very satisfied with ferritics.”





P 21
Corrosion resistance properties


Stainless steels are “stainless” because their chromium content gives
them exceptional resistance to corrosion.


All steels are prone to corrosion, to varying degrees. Stainless steels,
however, are significantly more corrosion resistant than carbon steels,
due to the chromium they contain. Chromium (not nickel, as is
sometimes imagined) is the key ingredient in the corrosion resistance
of stainless steels.




LOCALISED CORROSION RESISTANCE


Stainless steel applications are mostly maintenance-free but, in some
cases, light maintenance (removal of deposits, for example) may be
necessary, to ensure corrosion-free service life.


The corrosion resistance of stainless steels is determined more by
chemical composition than by austenitic or ferritic atomic structure.
Indeed, in terms of resistance to corrosion, ferritics and austenitics
can be seen as two interchangeable stainless steel families.


A comparison of the corrosion–resistance properties of the five ferritic
“groups” with those of austenitic type 304 clearly highlights the key
role of chromium and shows that the corrosion resistance of nickel-
containing (austenitic) grades can be matched by the majority of
ferritic families.


The above chart shows that only molybdenum-containing ferritic
grades have better localised (“pitting”) corrosion resistance than 304.
However, stabilised ferritic standard grades, although positioned
slightly below 304, still have very good resistance to pitting corrosion.




“…Ferritics and austenitics can be seen as two interchangeable
stainless steel families.”



P 21 Tables and pictures
Moisture separator reheater in grade 439, Europe.




FERRITIC/AUSTENITIC LOCALISED CORROSION RESISTANCE


- corrosion resistance +


410L


409


G1


430


G2


441


439


G3


304


436


316


444


G4


PRE
10
16
17
18
20
24




Radiator grill and trim, in grade 436.




Partially 444 building cladding, Brazil.





P 22
Group 1 ferritics are best suited to non-severe conditions, such as
inside the home (where the material is either not exposed to water
contact or gets regularly wiped dry) or outdoors in contexts where
some superficial corrosion is acceptable. In such contexts, this group
of ferritics has a longer life than carbon steel,.


Group 2 grades are effective in contexts involving intermittent contact
with water, in non-severe conditions.


Group 3 grades are suitable for similar contexts to those appropriate
for group 2 grades, but are easier to weld.


Group 4 ferritics are more corrosion resistant than type 304 and are
suitable for a wide variety of uses.


Group 5 includes, for example, grades with a very high chromium
content of around 29% Cr, plus 4% Mo, which makes them as
corrosion resistant in seawater as titanium metal.




THE PRE FACTOR


The “pre” or pitting resistance equivalent number is a measure of the
relative pitting corrosion resistance of a stainless steel grade in a
chloride-containing environment. The higher a grade’s pre value, the
more corrosion resistant that grade will be.


The pre comparison table shows at a glance that for every austenitic
grade there is a ferritic grade with comparable corrosion resistance.


In the commonly used shortened form of the pre formula
pre=%cr+3.3%Mo, molybdenum (Mo) is expressed as being 3.3 times
more effective than chromium against pitting corrosion. However,
chromium is always essential for providing the basic corrosion
resistance. Molybdenum cannot replace this “base” amount of
chromium in stainless steels, but can be used to boost corrosion
resistance.


Nickel content is not considered in the formula, since in most
applications it plays no role in resistance to pitting corrosion.




AVOIDING CORROSION


Stainless steel’s “passive” layer (see p. 59) needs oxygen to remain
intact. An accumulation of deposits can deprive the steel of oxygen at
critical points, which could lead to corrosion. Propagation of corrosion
may lead to eventual rupture of the part.




Nickel plays no role in resistance to pitting corrosion.”



P 22 Tables and pictures
Storage tank, in grade 444, Brazil.




AUSTENITIC/FERRITIC PRE COMPARISON


PREN = %Cr = 3,3 x % Mo + 16 x %N


317LN


316


304


446/447


444


436


430


409


439


AUSTENITIC


FERRITIC


SEA WATER 20°C


COASTAL ENV. 20°C


PURE WATER




Barbecue and trolley, in grade 430, Italy.





P 23
CORROSION RISK FACTORS


? embedded particles
? superficial deposits
? surface defects
? structural discontinuities
? salinity (salty areas, seawater, etc.)
? increase of temperature
? highly acidic conditions (strong acids)
? a strongly “reducing” environment


CORROSION-PREVENTING FACTORS


? a clean surface
? a smooth surface
? a pre-passivated surface
? ageing of the surface
? the washing effect (e.g. rain)
? higher chromium content
? oxidising conditions (O2 – not too strong)
? adding molybdenum





P 24
Corrosion sets in when ph reaches a critically low value (low ph = high
acidity). The “ph” level is a unit of measure describing the degree of
acidity or alkalinity of a solution. This is measured on a scale of 0 to
14.




ATMOSPHERIC CORROSION


This type of corrosion occurs on a steel surface, in the thin, wet film
created by a combination of humidity in the air and impurities. It is
often initiated by the presence of chlorides or sulphur compounds – in
an industrial environment. Typical conditions could be, for example,
chloride deposits in a humid, marine atmosphere.




CHOICE OF GRADE


Ferritic grades can be used in atmospheric environments of widely
varied corrosive severity. All parameters concerning in-service
conditions should be closely considered in selecting the appropriate
grade.


If slight localised surface rust (pitting corrosion), for example, is of no
importance in a certain application or environment, a lower-cost grade
might well be the correct material choice.




RULES OF THUMB


In the case of an aggressive environment, select a grade with a higher
chromium and/or molybdenum content.


Avoid rough surface finishes – favour a fine-polished surface with a
low Ra value.


Optimize design for “washability” (e.g. Min. 15° slope on upward-
facing surfaces).


Avoid “crevice-like” geometries.


Keep surface clean, by regular washing, to avoid staining and dust
accumulation.




“Ferritic grades can be used in atmospheric environments of widely
varied corrosive severity.”



P 24 tables and pictures
ATMOSPHERIC CORROSION RESISTANCE


marine


coastal


industrial


city


rural


indoor


409


410


430


439


304


444


316


447


material selection


rust unacceptable


small pits acceptable


no rust


Different environments require different ferritic (400-series) or
austenitic (300-series) grades, to resist atmospheric corrosion. In
industrial, coastal and marine environments, some localised (pitting)
corrosion may be acceptable, in certain applications.




Electrification box, in painted grade 410, S. Africa.




P 25
OXIDATION RESISTANCE


Unlike the two above types of corrosion, high-temperature cyclic
oxidation is “dry corrosion” occurring at high temperatures (>500°c)
and in oxidizing atmospheres, with or without thermal cycle.


When stainless steels are heated, their chromium content forms a
protective chromium oxide surface “scale” that delays further
oxidation. The scale and the metal substrate will have different
thermal expansion behaviour, which can affect the scale’s stability,
especially in service conditions of frequent thermal cycling. The
expansion coefficient of the scale is very low and if that of the metal is
too high, excessive scale will be generated, which will spall or crack
when the metal cools and contracts.


Thanks to their lower thermal expansion coefficient, ferritic grades are
much less prone than austenitic alloys to high-temperature cyclic
oxidation scaling. Where there is no spalling or cracking, there is no
new oxidation. This is a particular advantage in applications such as
heating systems, burners or exhaust systems, including manifolds.




BROAD APPLICATION POSSIBILITIES


These interesting corrosion-resistance properties are far from being
ferritic stainless steel’s only attractions. They are already enough,
however, to win friends for ferritics in the current climate of high
material costs.


Close examination of the properties of ferritics tends to pay dividends.
Some existing austenitic users might find, on examining their
specification, that a ferritic grade is actually highly appropriate for their
application.


Potential stainless steel users may be surprised by the exceptional
qualities of ferritics – and discover that stainless steel is a viable
option after all!




LIFE CYCLE COSTING: AN INVALUABLE GUIDE


The value of carrying out a life cycle costing study on any potential
application cannot be stressed too highly. Such a study will often
reveal that stainless steel – generally seen as a costly solution – is
actually the lower-cost option, viewed long-term.


Stainless steel’s corrosion resistance means longer life, less
maintenance, higher resale value, better appearance, etc. It renders
painting or galvanizing unnecessary. And as if this were not
inducement enough, the lower investment cost of ferritic grades can
be a clinching argument in favour of stainless steel as a material
choice.


Already widely used and respected, ferritic grades are nonetheless
still being “discovered”. The numerous wellproven existing
applications, however, light the way to many exciting new possibilities
for these fine steels.




…ferritic grades are much less prone than austenitic alloys to high-
temperature cyclic oxidation scaling.




…the lower investment cost of ferritic grades can be the clinching
argument in favour of stainless steel…



P 25
Gymnasium roof, in grade 445, S. Korea.




Burner, in grade 430.




Manifold, in grade 441.





P 26
INDUCTION COOKING REQUIRES THE MAGNETIC PROPERTIES
OF FERRITIC GRADES.




SEUNG TAE BAEK


TEAM LEADER WASHING MACHINE PROCUREMENT, LG
ELECTRONICS, KOREA.


“We use ferritic stainless steels mostly in washing-machine drums and
have done so from an early stage in our development of automatic
washing machines. In fact, in 2006, we used some 15,500 tons of
ferritics, against 2,500 ton of austenitics, so ferritics accounted for 86
percent of our stainless steel consumption.


“The advantage for us is simply that ferritic grades have very
satisfactory mechanical qualities but are less costly than austenitics.
Technically, advances in moulding technology and the development of
higher-quality ferritic grades mean we can use ferritics very
successfully these days. Cracking and creasing in the press remains
an occasional source of defects and we need to improve aspects of
the deep drawing process. However, with ferritics we get a result that
satisfies everyone in terms of both price and quality.”





P 27
Mechanical and physical properties


Ferritic stainless steel grades are fabrication-friendly and suitable for a
very wide range of applications.


Ferritics have good mechanical properties, occupying an intermediate
position in this respect when compared to the other stainless steel
families. They have higher yield strength than austenitics, while their
elongation and forming properties are equivalent to those of carbon
steels. Their physical properties include two characteristics in which
they out-perform austenitic grades: thermal expansion and thermal
conductivity.




MECHANICAL PROPERTIES


Generally speaking, the mechanical properties of a metallic alloy are
those that describe the material’s ability to compress, stretch, bend,
scratch, dent or break. The most commonly used criteria for
evaluating mechanical characteristics are:


Strength: the degree of resistance of a material to deformation. Two
critical values are generally considered:


yield strength, or the stress the material can be subjected to before
permanent plastic deformation occurs;


tensile strength, or the stress it can be subjected to before
rupture/failure.


Hardness: the degree of resistance to indentation by an applied load.


Toughness: the capacity to absorb deformation energy before
fracture.


Ductility (or plasticity): the ability to deform plastically without
fracturing.


Some of these properties can be measured by a tensile test. The
resulting stress-strain curves make it possible to determine yield
strength (YS), ultimate tensile strength (UTS) and total elongation at
failure (E). These tests result in the definition of a stress-strain curve
charting the performance of the metal in response to various loads.


The stress-strain curves show that while ferritic grade 430 has its
limits, it clearly performs exceptionally well within those limits.




“…Their elongation and forming properties are equivalent to those of
carbon steels.”



P 27 tables and pictures
MARTENSITIC STAINLESS STEELS


AUSTENITICS STAINLESS STEELS TYPE 304/316


HSLA STEELS


FERRITICS STAINLESS STEELS TYPE 430


CARBON STEELS


FERRITIC STAINLESS: EQUIVALENT TO CARBON STEEL


AUSTENITICS: EASIER TO FORM INTO COMPLEX SHAPES


STRESS (MPa)


UTS


YS


STRESS (Ksi)


STRAIN


UTS is measured in MPa (1MPa = 1N/mm3 = 145PSI = 0.1kg/mm3)
and represents maximum resistance at failure. YS refers to the
beginning of the “plastic” phase, where elongation no longer
disappears when the stress is removed.




Bus body frame, in grade 410, S. Africa.




Escalator steps, in grade SUS430, Japan.





P 28
Ferritic stainless steels have stress-strain curves fairly similar to those
of plain carbon steels. With moderately high yield strength (generally
higher than that of austenitics), moderately high ultimate tensile
strength and good total elongation performance, they offer good
ductility.




PHYSICAL PROPERTIES


The physical properties of a metallic alloy concern the material’s ability
to conduct heat, conduct electricity, expand or shrink, etc.


Ferritics are magnetic. They also have some other useful advantages
over austenitic grades. Their thermal conductivity, for instance, is
notably high. This means that they spread heat comparatively
efficiently – which makes them highly suitable for applications such as
electric irons or heat exchangers (tubes or plates).


The thermal expansion coefficient of ferritic stainless steels is similar
to that of carbon steel and much lower than that of austenitic stainless
steel. As a result, ferritics distort less when heated.



P 28 Tables and pictures
MECHANICAL PROPERTIES (COLD ROLLED)


The above table expresses properties in terms of U.S., Japanese and
European standards, comparing ferritic grades with standard
austenitic grade 304. Rm = ultimate tensile strength, Rp02 = yield
strength and A5/A80 = elongation to fracture.




Soleplate of electric iron, in buffed grade 430.




Boiler inner tube, in grade 444, S. Korea.




PHYSICAL PROPERTIES


Type of stainless steel


Density


g/cm3


Electric resistance


? ?mm2/m


Specific heat


0 ~ 100°C
J/kg • °C


Thermal conductivity


100°C
W/m • °C


Thermal expansion coefficient


0~200°C
0~600°C
10-6/°C


Young’s modulus x103


N/mm2


The modulus of elasticity of ferritic grades (at 20°c) is superior to that
of 304 austenitic. IS units: g/cm3 = kg/dm3 – J/kg • °C = J/kg • °K –
W/m • c = W/m • K –10-6/°c =10-6/°K – N/mm3 = MPa.





P 29
AS STRONG AS CARBON STEEL, LOW-CHROMIUM FERRITIC
GRADES ARE ALSO CORROSION RESISTANT. FERRITIC RAIL
ORE WAGONS THEREFORE HAVE A LOWER LIFE CYCLE COST
(LCC).





P 30
AESTHETIC AND HYGIENE FACTORS MAKE FERRITIC AN IDEAL
MATERIAL FOR GAS HOBS.




ZHANG SEN


DIRECTOR OF STAINLESS STEEL PURCHASING, QINGDAO
HAIER INTERNATIONAL TRADING CO. LTD., PEOPLE’S
REPUBLIC OF CHINA


“As one of the world’s leading white goods home-appliance
manufacturers, the Haier group uses ferritics in a broad range of
products, including washing machines, dish washers, gas cookers,
kitchen extractor hoods and microwave ovens. Having started using
these grades before the year 2000, we currently use around 14,500
metric tons of ferritics a year, representing about 85% of our total
stainless steel consumption. Ferritic grades are less costly than
austenitic grades and are ideally suited to these applications.


“Compared with austenitic grade 304, standard ferritics neither meet
the deep-drawing requirements of every part nor show as good
corrosion resistance in chloride environments, nor do they have the
same welding characteristics. However, they remain excellent
materials for home appliances and, in terms of manufacturing, the
adapted grades we use have good punching and drawing properties.
So we’re happy with ferritics.


“With the nickel price going up crazily, our purchasing costs for
stainless steel have increased sharply. Replacing austenitics with
ferritics not only lowers our raw-material costs but also saves
resources and protects our environment.


I would go so far as to say that while austenitics dominate today’s
stainless steel market, the future of stainless-steel consumption lies
with ferritics.”





P 31
Forming ferritic grades


Thanks to their good drawing characteristics, ferritic stainless steels
can meet the challenges of complex, three-dimensional designs.


Since their use in complex designs does not impair any of their
remarkable corrosion resistant, heat resistant and decorative qualities,
ferritic grades are often the right choice for both industrial and
consumer products.


Cold forming operations change the shape of strip or sheet products
by subjecting them to plastic strain. The forming operation involves
complex combinations of tensile and compressive loading, using a
combination of stretching and deep drawing deformations.


Although the overall drawing capacity of austenitic grades is better
than that of ferritics, some ferritic grades (notably titanium-stabilised,
17% chromium grades) show excellent drawing performance.




DRAWING FERRITIC GRADES


Drawing is the process most commonly used for forming hollow
objects from a flat sheet or “blank”. The good drawing behaviour of
ferritic stainless steels, coupled with their considerable price
advantage, can make ferritics the optimum choice.




HOW DRAWING WORKS


In the drawing process, shaping of the part is achieved by pressing a
flat sheet blank into a die cavity, by means of a punch. The metal is
drawn inwards, slipping between the die and the blankholder to form
the walls or “skirt” of the part.




“…some ferritic grades show excellent drawing performance.”



P 31 tables and pictures
Stamped top and bottom of boilers, in grade 441, S. Africa.




DEEP DRAWING


The slipping effect differentiates “drawing” from the “stretch-forming”
method, in which the blank is constrained by the blankholder.




Sink, in grade 430, Japan.





P 32
SUCCESSFUL DRAWING MEANS


? The absence of fracture
? Excellent surface appearance
? Minimum material consumption
? High fabrication productivity
? Low tool wear




THE LDR FACTOR


The Limited Drawing Ratio (LDR) is an important deep-drawability
parameter.


Limited Drawing Ratio (LDR) refers to the quotient of the maximum
blank diameter (D) that can be deep drawn into a cylinder in one step
and the diameter of that cylinder. LDR = D/d.


Ferritics have higher LDR values than austenitics, which makes them
particularly suitable for drawing.




STRETCH-FORMING FERRITIC GRADES


Ferritic grades are inferior to austenitics in pure stretch-forming.


The table below compares the stretching performance of various
grades “dome height” refers to the maximum degree of deformation
before “necking” (the phase just before failure) of a blank undergoing
stretching.




“Ferritics have higher LDR values than austenitics, which makes them
particularly suitable for drawing.”



P 32 Tables and pictures
Microwave oven, in grade 430, BA finish, S. Korea.




LIMITED DRAWING RATIO (LDR)




LDR GRADE COMPARISON


limited drawing ratio (LDR)




STRETCH FORMING


In stretch-forming, the drawn area becomes thinner.




STRETCH- FORMING PERFORMANCE


Dome height (K50) for different stainless steels


dome height (K50) in mm





P 33
FORMING LIMIT CURVES


In practice, industrial forming operations involve a combination of both
pure drawing and pure stretch-forming deformation, in a series of
“passes”.


Forming limit curves are a useful guide to maximum deformation
before failure, in both deep drawing and stretching processes.
Established for the principal stainless steel grades, they can be used
to analyse a forming operation.


These curves define local deformations during and after forming in
terms of two principal “true strains”: longitudinal (“major strain”) and
transverse (“minor strain”). The curves plot the effects of the various
combinations of these two strains, up to the point of fracture. The
higher the position of its curve the better a grade’s formability.




HOW FERRITICS BEHAVE


Generally, the work hardening and elongation characteristics of ferritic
stainless steels are comparable to those of highstrength carbon
steels. They are not the same as those of austenitic grades.


Design, construction and fabrication parameters and the material
properties of the ferritic grade concerned must be considered
together, in order to get the best out of the drawing process.




“RIDGING”


After certain forming operations, ferritic grades are sometimes prone
to surface phenomena known as “ridging” and “roping”.


This defect takes the form of a series of lines or ridges, parallel to the
sheet rolling direction. “ridging” describes the overall profile of the
deformed surface and includes both the microgeometry modifications
and the “roping” undulations caused by the deformation.


The addition of a stabilising element, such as titanium, will bring
improvement here. Titanium-stabilised grade 430 Ti gives remarkable
results in this regard and is thus often chosen to replace an austenitic
in applications involving deep drawing.




“Titanium-stabilised grade 430Ti is often chosen to replace an
austenitic in applications involving deep drawing.”



P 33 tables and pictures
major strain ?1


minor strain ??2




Stamped catalytic converter housing, in grade 441.




With and without surface defect.




Dryer drum: 409 welded sheet, formed by expansion.




Stamped manifold, in grade 441.





P 34
LUBRICATION


Good lubrication of the blank and the tooling is essential for successful
drawing, to avoid altering the surface appearance and to prevent
sticking phenomena detrimental to tool life.


If ferritic stainless steels are delivered with a bright, smooth surface, a
high-viscosity drawing lubricant may be used. Lubricants used with
stainless steels are special oils with high pressure resistance and
containing little or no chlorine. Uniformly applied on the blank, they are
easily removable from a stainless steel component after drawing.




TOOLING


Using the right tooling is vital, since it has a decisive influence on
friction conditions and thus on metal flow during the forming operation.
In special cases, tooling (mold and die) can be made of copper, iron or
aluminium bronze.


Surface treatments, such as a TiCN layer, may be applied, to increase
the life of the tooling. The blank holder and die tools have to be
carefully polished. The punch can remain rough.




THE FORMING PROPERTIES OF THE MAIN STEEL GROUPS


The table below compares the forming properties of ferritic stainless
steels (which have a specific metallurgical structure and hence
specific behaviour) to those of carbon steel and austenitic stainless
grades. It uses standard criteria applied in defining deformation
characteristics. “Bcc” (body-centred cubic) and “fcc” (face-centred
cubic) refer to the particular atomic structure of each type of steel.




“Lubricants used with stainless steels are easily removable from a
component after drawing.”



P 34 Tables and pictures
Welded bended tubes of a manifold, in grade 441.




Carbon Steel


Ferritic SS


Austentific SS


structure


bcc


fcc


work hardening


low


high


springback


deep drawing


excellent


good


stretch forming


ridging


no


can occur




Bending of 430Ti welded tube.


1.4003 hydroformed welded tube.


Deformation of the weld (1.4003).


Corrugated and finned heat exchanger welded tubes, in grade 439.





P 35
THE CASE FOR FERRITICS


While the tables and curves show that austenitics are superior,
overall, in terms of formability, the ferritic cost advantage is such that
looking into the use of a ferritic grade can often pay clear dividends.
Favouring the drawing method, especially, allows a remarkably wide
use of ferritic grades. Indeed, in certain specific cases – such as deep
drawing or springback effects – ferritics behave better than
austenitics.


Users should thoroughly discuss technical questions regarding the
use of ferritic grades with a reputable material supplier. Stainless steel
industry expertise is always on hand, to help users find ways to make
ferritic grades work and to ensure that the most appropriate grade is
chosen for any given application.




“…Favouring drawing allows exceptionally wide use of ferritic grades.”





P 36
INCREASINGLY STRINGENT ANTI-POLLUTION REGULATIONS
PLUS TECHNICAL AND ECONOMIC REQUIREMENTS MAKE
FERRITIC THE BASIC MATERIAL FOR EXHAUST SYSTEMS.




BERNHARD BLAESER


DIRECTOR, MACADAMS BAKING SYSTEMS (PTY) LTD SOUTH
AFRICA


“My company makes baking ovens and provers. With the substantial
increases in austenitic prices in the recent past, many players in the
industry have moved away from or are in the process of moving away
from stainless steel altogether. This is especially so in non-heat
applications, like the external panels of ovens, and other bakery
equipment not directly in contact with food. As ferritic prices have not
been as severely affected, an alternative is to substitute ferritic. In
essence then, manufacturers should consider substituting austenitics
with ferritics, rather than dropping stainless steel entirely.”




P 37
Joining ferritic grades


Ferritic grades are well suited to all the numerous methods of joining
stainless steels.


Welding: achieving complete joining of two or more materials through
melting and re-solidification of the base and filler metals.


Soldering: producing joining of materials by heating them to soldering
temperature (below the solidus of the base metal) in the presence of
filler metals with a liquidus of 450°c.


Mechanical joining: includes clinching, seaming, riveting and
mechanical fasteners.


Adhesive bonding: achieved by pressing clean, activated surfaces
together after applying a bonding agent that bonds using either
oxygen, water or a chemical reaction.




WELDING


Of the many welding processes developed for carbon steels that can
be used with stainless steels only a few are really appropriate for
these materials and have become standard: arc, resistance, electron,
laser-beam and friction welding.


Welding is the most efficient and least costly way to join metals. The
process makes possible structures of lighter weight (through the
optimal use of materials), joins all commercial metals and provides
design flexibility.


The welding characteristics of stainless steels are affected by
chemical composition, metallurgical structure and physical properties.
Ferritic grades have some useful advantages over austenitics when it
comes to welding, since they feature lower thermal expansion, lower
electrical resistivity and higher thermal conductivity.




STABILISED AND UNSTABILISED FERRITIC GRADES


On average, ferritic stainless steels tend to be less prone than
austenitics to the intergranular corrosion that can result from welding.



P 37 tables and pictures
Joining methods


Adhesive bonding


Soldering/Brazing


Mechanical joining


Welding





P 38
This is especially true of “stabilised” ferritic grades, which contain
strong carbide formers, such as titanium (Ti) and niobium (Nb). These
tie up the carbon in the steel, during the welding process, preventing it
combining with chromium to form chromium carbide. With consequent
chromium depletion at grain boundaries prevented, stabilised ferritic
Grades are virtually immune to intergranular corrosion.


To ensure complete stabilisation, Ti content must be five times greater
than carbon content, or Nb plus Ti must be three times greater than
carbon content. Sometimes, the introduction of nitrogen into this
formula can be advisable, to refine the grain in the melted zone.


Unstabilised ferritic grades contain no Ti or Nb and can therefore be
susceptible to intergranular corrosion in the heat affected zone, due to
chromium carbide formation. This effect is called “sensitisation”. Its
extent depends mainly on the carbon level.


The corrosion resistance of sensitised steels can, however, be
restored by annealing, at a temperature range of 600-800°c.




OVERMATCHING FILLER METALS


To ensure that a weld will be corrosion resistant, any ferritic filler metal
used should slightly overmatch the composition of the base metal in
terms of Cr, Mo, Ti and/or Nb alloying elements. This is because
heating will tend to cause a loss of chrome in the weld zone.
Alternatively, austenitic filler metal can be used, with an overmatch of
Cr and Mo alloying elements.




PROTECTIVE GASES


Being high in chromium, stainless steels are highly oxidizable in the
molten state. If they are not protected from air during the welding
process, chromium will be lost and oxides will form, resulting in lack of
soundness and decreased corrosion resistance in the weld. Protection
of the weld surface and neighbouring area is usually ensured by the
provision of an inert gaseous shield. This shielding gas can either be
an inert gas of pure argon (Ar) or helium (He) or a mixture of Ar and
he.


For the welding of ferritics, these shielding gases should be pure
argon or argon-helium mixtures. Argon-hydrogen mixtures, often used
for austenitic grades, bring a risk of hydrogen embrittlement in the
weld joint, in the case of ferritic grades. Argon is the most commonly
employed backing gas (protecting the rear of the workpiece). Nitrogen
must not be used with ferritic grades.




TROUBLESHOOTING FERRITIC WELDING PROBLEMS


As well as the risks referred to above, there can also be risks of
embrittlement by “phase formation” and “grain coarsening” at high
temperatures. Their solutions are listed in the following “remedies”
table.




“…stabilised ferritic grades are virtually immune to intergranular
corrosion.”



P 38 Tables and pictures
Degree of sensitisation


Grade weldability


Typical type i.e. 430


Low (C + N) i.e. 410L


Extra-low (C + N) + stabilization i.e. 430Ti, 409L





P 39
ARC WELDING


Arc welding is the form of welding most commonly employed with
ferritic grades.




GAS TUNGSTEN ARC WELDING (GTAW OR TIG/WIG)


In this process (also known as the Tungsten or Wolfam Inert Gas
Process), the energy needed to melt the metal is supplied by an
electric arc between the tungsten electrode and the workpiece.


Stainless steels are always welded in the straight-polarity DC mode
(the electrode being the negative pole), under an inert atmosphere. If
a filler metal is used, this will be in the form of uncoated rods (manual
welding) or coiled wire (automatic welding).




GAS METAL ARC WELDING (GMAW OR MIG)


Unlike the GTAW process, in GMAW (also known as the Metal Inert
Gas Process) the electrode is consumable. The arc is struck between
the molten filler wire and the workpiece. The shielding gas, injected
through the torch, around the wire, is usually argon with an addition of
2% to 3% oxygen, though more complex mixtures may be used for
certain welding modes.


Since the weld is essentially composed of filler metal, it is vital that the
filler metal’s composition should promote penetration and perfect
wetting of the base metal.


This high-productivity process is more difficult to perform than GTAW
welding but results can be excellent when the process is well
controlled.




RESISTANCE WELDING


In resistance welding, an electric current is passed through the parts
to be joined and welding is caused by resistance heating.



P 39 Tables and pictures
Stainless steel group


Special feature


Phenomenon


Cause


How to avoid


Unstabilised grades


Sensitisation


Poor corrosion resistance in welded zone


Cr-carbide precipitation in grain boundary


Annealing in temperature range 600-800°C


Stabilised grades


Grain coarsening


Poor toughness in welded zone


Excessive grain growth due to high temperature


Minimising the heat input of welding


High Cr-Mo grades


475°C embrittlement


Embrittlement occurs at 400~500°C


Sigma (?) phase formation due to decomposition of ??phase


Reheating at 600°C and cooling rapidly


High Cr-Mo grades


Sigma (?) phase embrittlement


Embrittlement occurs at 550~800°C


Sigma (?) phase formation


Reheating above 800°C and cooling rapidly


Unstabilised grades


Martensitic phase embrittlement


Embrittlement occurs in lower Cr and higher-C types


Martensitic phase formation due to faster cooling


Removing the martensitic phase by long annealing in the 600-700°C
range




Welded tank, grade 441, S. Africa.




Ferritic tube mill, Brazil.




Welded structural frame in grade 1.4003.





P 40
Several resistance welding techniques exist, the most common being
spot welding and seam welding. In both cases, the major advantages
of resistance welding are:


The limited modification of the microstructure in the heat affected
zones (HAZ);


The virtual absence of surface oxidation, if the sheets are correctly
cooled;


The very low level of distortion of the sheets after welding;


“Forging” deformation during welding, which is particularly useful for
the joining of ferritic steels.


Compared to the requirements of mild steel, the main differences in
process parameters for stainless steel are the lower and more
precisely adjusted welding powers (due to low electrical and thermal
conductivities) and higher electrode forces.




OTHER PROCESSES


Other welding processes applicable to ferritic stainless steels include
electron and laser beam welding and friction welding.




SOLDERING AND BRAZING


Soldering and brazing are processes for joining metallic components
in the solid state by means of a fusible filler metal that has a melting
point well below those of the base metals. Soldering employs soft filler
alloys with melting points below 450°c, whereas brazing alloys are
harder and melt at higher temperatures.


The advantages of these joining techniques include the following
convenient features:


? They require only a low-temperature heat source.
? Joints can be permanent or temporary.
? Dissimilar materials can be joined.
? The rate of heating and cooling is slow.
? Parts of varying thicknesses can be joined.
? Realignment is easy.
? They require less heat than welding.


In deciding on the suitability of soldering or brazing for a specific
structural joint, care should be taken to evaluate carefully the strength
or performance required of the joint.


In all cases, while carrying out the joining, it is essential to ensure
perfect wetting of the two solid parts by the molten filler material.


Sensitisation will occur more readily in the case of unstabilised
grades.




PICKLING, PASSIVATION AND DECONTAMINATION


The slight discoloration resulting from welding should be eliminated by
either mechanical descaling or a chemical treatment called pickling.


Pickling is carried out in a fluonitric solution (10%hno3 + 2%hf) or
using pickling pastes designed specially for welds.


It can be followed by a passivation and decontamination treatment –
to help the passive layer (see p. 59) reform quickly and remove
organic metallic residues (iron-rich particles). The process involves
immersion in a cold 20%-25% nitric acid bath.


Local passivation of weld zones can also be carried out by means of
special passivating pastes.



P 40 tables and pictures
Soldering a gutter, tin-coated grade 430Ti.




Before and after pickling.




Brazing welded tubes, grade 441.





P 41
MECHANICAL JOINING


Mechanical joining techniques used for carbon steels can be equally
successfully used with stainless steels.


Mechanical joining has certain advantages:


? Dissimilar materials can easily be joined.
? There is no heat affected zone (HAZ).
? Parts of varying thicknesses can be joined.
? There is no thermal expansion.


Consideration should, however, be given to the fact that the
mechanical properties of mechanical joints may have certain
weaknesses, since there is no complete coalescence of the joining
partners. The joining operation method may also require two-side
access.


It is vital to ensure that none of the surfaces in contact are liable to
induce corrosion due to galvanic coupling. To avoid this risk, parts to
be joined should preferably be made from the same stainless steel or
an equivalent grade. Certainly any screws, bolts, fasteners or rivets
should be of stainless steel.




SCREWING AND BOLTING


Stainless steel screws and bolts are available in all the principal
grades. While 17% Cr ferritic grades are best suited to use in only
mildly aggressive environments, their corrosion resistance in chloride-
containing media is enhanced by the addition of 1% to 1.5%
molybdenum.




RIVETING


This technique is always carried out at ambient temperature, using
rivets of a maximum diameter of about 5 mm. It is strongly
recommended that joints be designed in such a way that the rivets are
loaded in shear rather than in tension.




CLINCHING


This relatively recent joining technique can be readily applied to
stainless steels, thanks to their high ductility. Being a cold forming
process, it causes no structural modification or surface oxidation.


Since the sheets to be joined must overlap, clinching is usually
combined with an adhesive bonding, producing a hermetically sealed
joint, to avoid risk of crevice corrosion. This can also damp vibrations.




SEAMING


In this mechanical sheet-joining technique, the edges of one or both of
the sheets concerned are bent through an angle of 180°, to produce a
tight seam. As with clinching, different materials can be joined – for
example, an austenitic and a ferritic grade.


Perfectly leak-proof joints can be achieved with this technique, which
is widely used in the manufacture of domestic appliances.



P 41 Tables and pictures
Mechanical joining of stainless steels


Mechanical fasteners


Without any additional part


Riveting


Screws


Self-piercing and thread-forming screws


Clinching


Seaming


Self-piercing rivets




Auto-riveting on 430, 1.5 mm.




Exploded display of washing-machine interior.





P 43
ADHESIVE BONDING


Adhesive bonding can be employed to reinforce mechanical joints,
and in its own right for joining thin stainless steel sheets.


The advantages of adhesive bonding are:


There is no modification of the surface appearance, geometry or
microstructure of the assembled areas.


Dissimilar materials can be joined easily and aesthetically.


Correctly designed, joints can have excellent fatigue strength.


The method can provide thermal, electrical or acoustic insulation.


Parts of varying thickness can be joined.


Points to take into consideration, however, include the fact that such
joints will tend to have a temperature limit of 200°c and will have a
certain sensitivity to moisture. Adhesive joints will not be as strong as
joints produced by welding or brazing. For this reason they are mostly
used to produce lap joints, with the load spread over a sufficient area
to limit local stresses.


It is also possible that a smooth-surfaced stainless steel (especially
bright annealed) will not have good adhesive properties.


After roughening, surfaces should be very clean, dry and well
prepared. The essential condition for good bonding is satisfactory
wetting of the substrate by the adhesive.


As an example of adhesive bonding, bus and coach manufacturers
now often construct a body frame of stainless steel shaped sections,
often in ferritic grade 1.4003/410. The skin (sheet and/or glass) is
adhesively bonded to this body frame. This approach increases the
vehicle’s life and reduces its weight.



P 41 tables and pictures
Bonding of guttering, tin-coated 430Ti.




Windows bonded to a 1.4003 tubular frame.





P 44
NICK MCDONALD


MARKETING MANAGER, LINCAT LIMITED, LINCOLN, UK


“Established in 1971, Lincat has been a front runner in the
manufacture of professional kitchen equipment for 36 years. Grade
430 ferritic stainless steel, which we’ve used from the start, is the
absolute bedrock of our product range.


“This grade ideally matches the spec of these applications and is an
economical way of enjoying the advantages of stainless steel, which
are so important when dealing with food preparation and presentation.
In addition, 430’s relatively low thermal expansion characteristic is a
big technical plus in high-temperature applications.


We make virtually everything in 430 ferritic, except some components,
such as the inner tanks of wet-well bains-marie, where we are still
using 304. On the fabrication side, our products are designed to be
very easy to keep clean and 430 is an easy material to work with in
this respect.


“Staying closely in touch with our customers’ needs, we’ve built a
reputation for outstanding product reliability and sturdy, durable
construction. Grade 430 ferritic is an essential part of the equation.
We and our customers are very satisfied with it.”





P 45
Products and applications


Ferritics are often associated with decorative trim, sinks and car
exhausts. Their actual and potential usefulness extends far beyond
these narrow confines…


Ferritic stainless steels are straight chromium steels, containing no
nickel. They resist corrosion and oxidation, are highly resistant to
stress corrosion cracking, are usefully magnetic and offer a host of
other technical, aesthetic and practical advantages. They often prove
better value in the long run than carbon steel and are significantly less
costly than their nickel-containing, austenitic cousins.


Their range of uses is currently under-explored and the pages that
follow show something of the range of possible uses of these
materials. The chapter covers applications from many sectors of the
market and many parts of the world.


This publication aims to inspire actual and potential users of ferritic
stainless steels by illustrating existing, successful applications. It
further aims to encourage responsible and informed material selection
– optimal matching of material and application has never been more
important.




AUTOMOTIVE


EXHAUST SYSTEM COMPONENTS


Grade 1.4509/441, diesel particle filter, Peugeot 607, Faurecia


Grade 1.4509/441, manifold, Faurecia


Grade 1.4512/409, silencer, Faurecia, S. Korea


Grade 304 & 441, diesel particle filter, E Class Mercedes, Faurecia


Grade SUS430J1L Catalytic Converter Shell, Honeycomb In 20%Cr-
5%Al


Grade 1.4509/441, catalytic converter, Faurecia




DECORATIVE TRIM


Grade SUS430, S. Korea


Grade SUS430J1L, Japan





P 46
Grade SUS430, S. Korea


Grade 1.4016/430, blackcoated trim, USA


Grade 1.4113/434, USA




S.U.V. FRONT ELEMENT


Grade 1. 4513, Plastic Omnium, France




CAR BOOT SILL


Grade 1.4510/430ti, Peugeot 307, France




HEADLIGHT


Grade 1.4513, headlight trim, Italy




TRUCK


Grade 1.4113, truck decorative trim, USA




CLAMPS


Grades 1.4509/441 and 1.4016/430




FILTERS


Grade 1.4512/409l, Taiwan, China




BRAKE DISCS


Grade 1.4028/420




THERMOSTAT


Grade 1.4512/409, France




PADDLE WHEEL


Grade 1.4512/409, 1.5 mm thick, France





P 47
BUILDING & CONSTRUCTION


ACCESSORIES


IRONMONGERY – WINDOW HINGES & FASTENERS


Grade 1.4016/430, Europe




GUTTERING


Grade 1.4510/430Ti, tin-coated, Europe


Grade 1.4521/444, Europe




CHIMNEY DUCT


Grade 1.4521/444, Europe




CONSTRUCTION


SQUARE-TUBE EXTERIOR INSULATING MEMBERS


Grade SUH409L (1.4512/409), JSSA, Japan




EMERGENCY HOUSING


Grade 1.4016/430, painted, VERNEST® and Centro Inox, Italy




COMMUNICATION-SYSTEM SHELTER


Grade SUS436L (1.4526/436), JSSA, Japan




FACTORY BUILDING


Grade 1.4003, Columbus new finishing mill, S.Africa




ROOF STRUCTURE


Roof-support: a potential application for ferritics.




BUILDING


Grade SUS445J1 & SUS445J2, Nakano Sakaue Bldg., 1996, Japan


Resin Coated SUS445J2, Phoenix Resort, 1994, Japan


Outer Parts SUS445J1, Inner SUS304, Nihonbashi Mitsui Bldg., 2005,
Japan





P 48
CIVIL CONSTRUCTION


NOISE-ABSORBING PLATE FOR OVERPASS


Grade SUS436 (1.4526/436), JSSA, Japan




STRUCTURAL STEELWORK OF BRIDGE


Grade 1.4003/410 painted, SASSDA, South Africa (bridge in service
for over 8 years).




INNER WALL OF TUNNEL


Grade SUS430J1L (1.4016/430), JSSA, Japan


Grade 1.4016/430, painted, Monte Mario Tunnel, Centro Inox, Italy




WINDBREAKER FENCE


Grade SUS445J2, JSSA, Japan




PLATFORM SCREEN DOOR


Grade 1.4510/439, hair-line finish, KOSA, S. Korea




ELECTRIFICATION MASTS


Grade 1.4003 (first major application in 1982, along seashore – 10m
from surf, no corrosion), S. Africa




POWER GENERATION


Grade 1.4003/ 410, x-grid cooling tower packing, S. Africa




CLADDING


BUILDING FAÇADE CLADDING


Grade SUS445m2, low-reflectivity matt finish, ASSDA, Australia


Grade 1.4521/444 brushed no. 4 (horizontal panels), Vivo Building,
Rio De Janeiro, Nucleo Inox, Brazil (coastal environment)


Grade SUS445J2, Future Science Museum, JSSA, Japan


Grade 1.4526/436, Ugine & Alz Steel Service Centre, Arcelor Mittal
Stainless, Katowice, Poland





P 49
LIFTS


ESCALATOR STEPS


Grade SUS430LX (1.4016/430), Japan




LIFT PANELS


Grade 1.4510/439




ROOFING


MEDIADOME ROOF


Grade SUS445J2, Kitakyushu Mediadome (Fukuoka Pref.)1998,
Japan




SCHOOL ROOF


Grade 430Ti (standing seam technique), Ugine & Alz, Austria




GYMNASIUM ROOF


Grade 445, KOSA, S. Korea




CANOPY


Grade 446, KOSA,
Seoul, S. Korea.




CHALET ROOF


Grade 1.4510/430Ti (standingseam
technique), Ugine & Alz,
Germany.




AIRPORT ROOF


grade SUS447J1, Kansai airport terminal building (architect Renzo
Piano), JSSA, Osaka, Japan




URBAN FURNITURE


LAMP POST

Grade 1.4510/439, electro-polished welded pipe, KOSA, Seoul, S.
Korea




POST BOXES


Grade 1.4003/410, painted, SASSDA, South Africa. “Utility” ferritics
are often painted, when aesthetic considerations are important.




TICKET MACHINE ON RAILWAY PLATFORM


Grade 1.4003/410, painted (15 years in service), SASSDA, UK




ELECTRIFICATION BOXES


Grade 1.4003/410, painted (15 years in service), SASSDA, S. Africa





P 50
COMMERCIAL FOOD EQUIPMENT


BAKERY OVEN


grade 430, Macadams Baking Systems (PTY) Ltd, S. Africa




GAS COOKING EQUIPMENT


Grade 430, Lincat, UK




COFFEE SERVER


Grade SUS430J1, JSSA, Japan




HEATED MERCHANDISER


Grade 430, Lincat, UK




CONVEYOR TOASTER


Grade 430, Lincat, UK




MICROWAVE OVEN


Grade 430 (interior and exterior), JSSA, Japan




BURNER RANGE


Grade 430 (gas hob), POSCO, S. Korea




REFRIGERATOR


Resin-coated SUS430J1L panel, JSSA, Japan




COFFEE MACHINE


Grade 430, Lincat, UK




RESTAURANT TROLLEY


Grade 430




DISPLAY MERCHANDISER


Grade 430, Lincat, UK




WALL CUPBOARD


Grade 430, Lincat, UK





P 51
HOME & OFFICE


In the following applications, ferritic (400-series) grades are now
established as ideal, on grounds of their aesthetic quality, their
resistance to cleaning and disinfection agents, their low thermal
expansion coefficient and their magnetism (for induction cooking).
They also offer considerable economic advantages over other
materials.


DOMESTIC COOKING EQUIPMENT


GAS COOKER


KOSA, S. Korea




VARIOUS


TKN, Germany




MICROWAVE OVEN


grade SUS430J1, JSSA, Japan




GAS COOKING TOP


TSSDA, Thailand




BARBECUE


Grade 1.4016/430, windscreen and brazier, Ompagrill and Centro
Inox, Italy


Grade 1.4016/430 barbecue, USA




COOKWARE AND POTS


WOK




INDUCTION COOKWARE


Groupe SEB (Tefal)




PRESSURE COOKER


Grade 430, Groupe SEB




PANS


Grade 430, POSCO, S. Korea




DISHWASHERS


DISHWASHER


Grade 430 interior panel


Resin coated SUS430J1L outer panel, JSSA, Japan





P 52
Grade 430 (exterior and interior panel), Haier, PRC




ELECTRICAL APPLIANCES


MIXER


Grade 1.4513, TKN, Italy


Grade 430




ELECTRIC RICE COOKER


Resin coated SUS430, JSSA, Japan




ELECTRIC KETTLE


Resin coated SUS430, JSSA, Japan




EQUIPMENT


SHELVES


Grade 1.4016/430, horizontal shelves, Graepel and Centro Inox, Italy




RUBBISH CONTAINER


Grade 1.4016/430, Graepel and Centro Inox, Italy




PARTITION


Grade 430, POSCO, S. Korea




HANDRAIL


Grade 430 welded tube




LCD FRAME


Grade 410, POSCO, S. Korea




HOODS


KITCHEN HOOD


Grade 430, Blanco, TKN, Germany


Grade 430, Falmec, Nucleo Inox, Brazil





P 53
KITCHENWARE


LIQUID DISPENSER


Grade 430




ELECTRIC KETTLE


Grade 430, Groupe SEB




PASTA COOKING POT


Single layer SUS430J1L (induction heating), JSSA, Japan




REFRIGERATORS


FRIDGE & FREEZER


Grade 430 panel


Grade 430 door panel, TKN, Germany




SINKS


DOMESTIC KITCHEN SINK


Grade 430, Tramontina, Brazil




WASHING MACHINES


DRUM


Grade 430 (drum and exterior panel), TKN, Germany


Grade 430 drum, LG electronics, S. Korea




DRYERS


DRUM


Grade SUS430, JSSA, Japan


Grade 409, Whirlpool, Europe




TABLEWARE


ASIAN SPOON


Grade 430




CUTLERY


400-series grades, IKEA





p 54
INDUSTRY


Ferritic is extensively used where the maintenance of carbon steel is a
virtual impossibility.


DAM OUTLET PIPES


painted grade 1.4003/410, Columbus, S. Africa




FLOOD CONTROL GATES


painted grade 1.4003/410, Columbus, S. Africa




TANKS


Grade SUS430J1L, coloured-resin coated (outer jacket), JSSA, Japan




FRACTIONATING COLUMN


Grade 410S, Europe




CONVEYOR BELT


Grade 410S, Europe




BURNERS


Grade 1.4509/441 (high oxidation resistance)




Burner


Grade SUS430, boiler gas burner, JSSA, Japan.




BOILERS


BOILER INNER TUBE


Grade 1.4521/444, KOSA, S. Korea




“HYDROBOIL” INSTANT BOILING WATER HEATER


Grade 1.4521/444, ZIP industries and ASSDA, Australia




BOILER


Grade 444, Europe




HOT WATER TANK


Grade 1.4521/444, Europe


Grade SUS444, JSSA, Japan





P 55
FOOD PROCESSING


WALLS & CEILINGS


Grade 445M2, Melbourne, Australia




HEAT EXCHANGERS


Substitution from cupro-nickel (due to erosion by vapour and migration
of copper), carbon steel (erosion problems) and 304 (higher thermal
expansion than the carbon steel frame).


MOISTURE SEPARATOR REHEATER WELDED TUBES


Grade 1.4510/439, VALTIMET, Europe


FEEDWATER HEATER WELDED TUBES


Grade 1.4510/439, VALTIMET, Europe




CONDENSER WELDED TUBES


Grade 1.4510/439, VALTIMET, Europe




SOLAR WATER HEATERS


SOLAR WATER HEATER


Grade SuS444, Suncue Company Ltd. and YUSCO, Taiwan, china


Grade 1.4509/441 (cylinder), Sun tank and SASSDA, S. Africa


Solar panels: frame and collector a potential application for ferritic
Grades 441/444.




SUGAR INDUSTRY


CONVEYOR SYSTEM


Grade 1.4003/410, Columbus, S. Africa. Here, ferritic has lasted over
18 years.




SLATE CARRIER


Grade 1.4003/410, Columbus, S. Africa. This machine has been in
service 22 years.




SCALDING JUICE HEATER COVER


Grade 1.4003/410, Columbus, S. Africa. Carbon steel (top) compared
to ferritic (bottom) after 6 years in service.




HEAT EXHANGER TUBES


Grade 1.4521/444, Nucleo Inox, Brazil




CRYSTALISER & DIFFUSER


Grade 1.4003/410, Columbus, S. Africa





P 56
TANKS


WATER TANKS & PIPES


Grade 444, Brazil




WATER TANK


Grade 444, KOSA, S. Korea


Partially in grade SUS444, finish no. 4, JSSA, Japan




FERMENTATION AND STORAGE TANK


Grade 444, Nucleo Inox, Brazil. Sander Inox has successfully
produced such tanks for 7 years.


Grade 444, Nucleo Inox, Brazil




MOTORCYCLE


MOTORCYCLE EXHAUST


Grade 1.4512/409l, YUSCO, Taiwan, China


Grade 1.4509/441, Centro Inox, Italy. The new Vespa ET2 is equipped
with a ferritic catalytic silencer.


Grade 409L


Grade 409L, Acesita, Brazil




DISC BRAKE ROTOR


Grade SUS410SM1, JSSA, Japan


VARIOUS


Grade 420 brake discs, 1.4113 decorative trim, Italy





P 57
TRANSPORTATION


BUS & COACH BODY FRAME


Grade 1.4003/410, Columbus, S. Africa.


Grade 1.4003/410 (lower part painted), Columbus, S. Africa.


Grade 1.4003 welded tubes and panel, Solaris Bus & Coach Co.
Poland




CONTAINER


Grade 1.4003/410 (frame and panels), POSCO, S. Korea


Grade 1.4003/410, painted (frame and door panels)




COAL WAGON


Grade 1.4003/410 (panels), Columbus, S. Africa. In service for over
20 years.


Grade 1.4003/410 (panels), Columbus, S. Africa. In service for over
15 years.


Grade 1.4003 (interior of previous), SASSDA, S. Africa


Grade 1.4003/410, painted, Europe


Grade 409/410, painted, TISCO, PRC


Grade 1.4003, SASSDA, S. Africa




TRAMWAY


Grade 1.4003/410 (body frame and painted panels), Europe





P 59
APPENDICES


The chemical composition of ferritic stainless steels


Ferritic stainless steels have properties similar to those of mild steel
but show much better corrosion resistance. Their development began
over a century ago.


EARLY FERRITICS


Stainless steel was “discovered” around 1900–1915. As with many
discoveries, it was actually the result of the accumulated efforts of
several scientists. Research was published in England, France and
Germany on alloys with compositions that would be known today as
the 410, 420, 430, 442, 446 and 440c grades.


Stainless steels must have a very low level of carbon. For many years
it was difficult to obtain such a low carbon level, which explains the
late arrival of good ferritic grades (in the 1980s).




THE GRADES AND THEIR CHEMISTRIES


Chromium (Cr) is by far the most important alloying element in the
production of stainless steel. It forms the “passive” surface film that
makes stainless steel corrosion resistant and increases scaling
resistance, wear resistance and tensile strength.


A minimum of 10.5% chromium content (by weight) is required for the
protective, self-repairing surface layer of chromium oxide to form
reliably. The higher the chromium content, the stronger the passive
layer.


If the stainless steel surface is machined or accidentally damaged, the
passive layer instantaneously re-forms, in the presence of air or water.




CHEMICAL COMPOSITION AND INTERNATIONAL STANDARDS


The following tables show the chemical analysis of the five groups of
ferritic stainless steels.



P 59 Tables and pictures
THE PASSIVATION PROCESS


Standard steel


Fe+C


Formation of iron oxyde


Rust


Stainless steel


Fe+C + Cr>10,5%


Formation of Chromium oxyde


Passive layer




THE 5 GROUPS OF FERRITIC GRADES


Group 1


10%-14%


Types 409, 410, 420
Cr content: 10%-14%


Group 2


14%-18%


Type 430
Cr content: 14%-18%


Group 3


14%-18% stabilised


Types 430Ti, 439, 441, etc.
Cr content: 14%-18%. Include stabilizing elements such as Ti, Nb, etc.


Group 4


Added Mo


Types 434, 436, 444, etc.
Mo content above 0.5%


Group 5


Others


Cr content of 18%-30% or not belonging to the other groups





P 60 – 61
STANDARDS:


ASTM A 280 - 06C, NOVEMBER 2006


EN 10088-2, SEPTEMBER 2005


JIS G 4305, 1991




GROUP 1


10%-14%Cr


GROUP 2


14%-18%Cr


GROUP 3


14%-18%Cr stabilised


GROUP 4


Added Mo


GROUP 5


Others


Chemical component (Maximum weight %)


Standard


Ref.


C


Si


Mn


P


S


Cr


Mo


Ti


Nb


Cu


Al


N


Ni





P 62
IMPRESSIVE USE OF FERRITIC WELDED TUBES IN A POWER
STATION CONDENSER.





P 63
APPENDICES


Surface finishes


Surface finishing treatments applied to stainless steels can take many
forms. The main finishes are described below. Ferritic surface finishes
are the same as those for austenitic and other grades.


Description

ASTM

EN10088-2

Notes







Hot rolled

1
1E/1D
A comparatively rough,
dull surface produced
by hot rolling to the
specified thickness,
followed by annealing
and descaling.
Cold rolled

2D
2D
A dull, cold rolled finish
produced by cold rolling
to the specified
thickness, followed by
annealing and
descaling. May also be
achieved by a final light
pass on dull rolls.

Cold rolled

2B

2B
A bright, cold rolled
finish commonly
produced in the same
way as No. 2D finish,
except that the
annealed and descaled
sheet receives a final
cold roll pass on
polished rolls. This is a
general-purpose cold
rolled finish and is more
readily polished than
No. 1 or No. 2D.
Bright
annealed

BA
2R

BA finish produced by
performing bright
annealing in an inert
atmosphere after cold
rolling. Smoother and
brighter than No. 2B.
Brushed or
dull
polished

No. 4

1J/2J
A general-purpose
bright polished finish
obtained by finishing
with a 120-150 mesh
abrasive, following
initial grinding with
coarser abrasives.

Satin
polished
(matt)

No. 6

1K/2K
A soft satin finish
having lower reflectivity
than brushed (or dull
polished) finish. It is
produced by a tampico
brush.

Bright
polished
(mirror)

No. 8

1P/2P
The most reflective
finish commonly
produced. It is obtained
by polishing with
successively finer
abrasives then buffing
with a very fine buffing
compound. The surface
is essentially free of grit
lines caused by
preliminary grinding
operations.

Electropolis
hed
surfaces

-
-
This surface is
produced by electrolytic
attack. This
electrochemical process
improves the surface
finish by removing
peaks of surface
irregularity.





(nb: the above table is not official and should be used only as a guide)





P 64-64
APPENDICES


References


Bucher, L., P.-O. Santacreu, et al. “Elasto-Viscoplastic behaviour of
ferritic Stainless Steel AISI 441-EN 1.4509 from room temperature to
850°c.” Journal of ASTM International (JAI) Vol. 3, Issue 7 (2006).
also: Fatigue and Fracture Mechanics (symposium), Vol. 35.


Cunat, Pierre-Jean. “Working with Stainless Steels” Paris: SIRPE,
1998.


Fedosseev, A, And D. Raabe. “Application of the method of
superposition of harmonic currents for the simulation of
inhomogeneous deformation during hot rolling of FeCr.” Scripta Metall.
Mater Vol. 30 (1994): 1-6.


Gümpel, P., N. Arlt, et al. “Simulation des korrosionsverhaltens von
nichtrostenden Stählen in PKW-Abgasanlagen.“ Automobiltechnische
Zeitschrift (ATZ) no. 4 (2004): 350-356.


Huh, M.-Y., J.-H. Lee, et al. “Effect of Through-Thickness Macro and
Micro-texture gradients on ridging of 17%Cr Ferritic Stainless Steel
Sheet.” Steel Research Vol. 76, no. 11 (2005): 797-806.


Kim, D. S., J. H. Park, et al. “Improvement of Cleanliness of 16%Cr-
containing Ferritic Stainless Steel in AOD Processes”, La Revue de
Metallurgie no. 4, Paris (2004): 291-299.


Kim, K, Y. Kim, et al.“POSCO’s development of Ferritic Stainless
Steel.” The Second Baosteel Biennial Academic Conference Vol. 3,
Shanghai, china (2006).


Lee, S.-B., M.-C. Jung, et al. “Effect of Niobium on Nitrogen Solubility
in High Chromium Steel.” ISIJ International Vol. 42 (2002): 603-608.


Lee, S.-B., J.-H. Choi, et al.“Aluminum Deoxidation Equilibrium in
Liquid Fe-16 Pct Cr Alloy.” Metallurgical and Materials Transactions B,
Vol. 36b (2005): 414-416.


Miyazaki, A., J. Hirasawa, et al. “development of high heat-resistant
ferritic Stainless Steel with high formability, RMH-1, for Automotive
Exhaust Manifolds.” Kawasaki Steel Technical Report no. 48 (2003):
328.


Miyazaki, A., Takao, et al. “Effect of Nb on the Proof Strength of
Ferritic Stainless Steels at Elevated Temperatures.” ISIJ International
Vol. 42, No. 8 (2002): 916-920.


Murayama, M, N. Makiishi, et al. “Nano-scale chemical analysis of
passivated surface layer on stainless steels.” Corrosion Science Vol.
48 (2006): 1307-1308.


Park, J. H., D. S. Kim, et al.“Inclusion Control of Fe-16%Cr Stainless
Steel Melts by Aluminum Deoxidation and Calcium Treatment.” AIST
Transactions in Iron & Steel Technology Magazine Vol. 4, No. 1
(2007): 137-144.


Park, S. H., K.Y. Kim, et al.“Evolution of Microstructure and Texture
Associated with Ridging in Ferritic Stainless Steels.” ICOTOM 13,
Seoul, Korea (2002): 1335.


Park, S. H., K. Y. Kim, et al. “Investigation of Microstructure and
Texture Evolution in Ferritic Stainless Steels, ISIJ International Vol.42,
No.1 (2002): 100.


Park, S. H., K. Y. Kim, et al. “Effect of Annealing Process on the
Microstructure and Texture Evolution in Type 430 Stainless Steel.”
Journal of the Korean Institute of Metals & Materials Vol.39, No. 8
(2001): 883.


Park, S. H., K. Y. Kim, et al. “Effect of annealing process on the
microstructure and texture evolution in Fe-16%Cr ferritic stainless
steel.” Rex & GG Aachen, Germany (2001): 1203.


Park, S. H., K. Y. Kim, et al. “Effect of initial orientation and austenitic
phase on the formation of deformation band and recrystallization
behavior in hot rolled ferritic stainless steels.” THERMEC 2000, Las
Vegas, USA (2000): 163.


Raabe, D. “Experimental investigation and simulation of
crystallographic rolling textures of fe-11wt.% cr.” Materials Science
and Technology No. 11 (1995): 985-993.


Raabe, D. “On the influence of the Chromium content on the evolution
of rolling textures in ferritic stainless steels.” Journal of Materials
Science No. 31 (1996): 3839-3845.


Raabe, D. “Metallurgical reasons and mechanical consequences of
incomplete recrystallization.” Stahl und Eisen No. 120 (2000): 73–78.


Raabe, D, and K. Lücke. “Influence of particles on recrystallization
textures of ferritic stainless steels.” Steel Research No. 63 (1992):
457-464.


Raabe, D, and K. Lücke. “Textures of ferritic stainless steels.”
Materials Science and Technology No. 9 (1993): 302-312.


Santacreu, P.-O., L. Bucher, et al. “Thermomechanical fatigue of
stainless steels for automotive exhaust systems.” La Revue de
Métallurgie No. 1, paris (Jan. 2006): 37-42.


Santacreu, P.-O., O. Cleizergues, et al. “Design of stainless steel
automotive exhaust manifolds.”La Revue de Métallurgie nos. 7-8,
Paris (July-Aug. 2004): 615-620. also: JSAE paper No. 20037127
(2003).


Schmitt, J.-H., F. Chassagne, et al. “Some Recent Trends in Niobium
Ferritic Stainless Steels”. Proceedings of the symposium Recent
Advances of Niobium Containing Materials in Europe, Düsseldorf (20
May 2005): 137.


Sinclair, C. W., And J.-D. Mithieux, “Coupling recrystallization and
texture to the mechanical properties of ferritic stainless steel sheet.”
Proceedings of 2nd International Conference on Recrystallization &
Grain Growth, Annecy, France (30 Aug.–3 Sept. 2004): 317.


Sinclair, C.W., J.-D. Mithieux, et al. “Recrystallization of Stabilized
Ferritic Stainless Steel Sheet”, Metallurgical and Materials
Transactions A, Vol. 36a (Nov. 2005): 3205.


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and Applications Series Vol. 8, Euro Inox (2006).


Toscan, F., Galerie, et al. “Relations between Oxidation Kinetics and
Chromium Diffusion in Stainless Steels.” Materials Science Forum
Vols. 461-464 (2004): 45-52. Online at www.scientific.net.


Yazawa, Y., Y. Kato, et al. “Development of Ferritic Stainless Steel
with Excellent Deep Drawability for Automotive Fuel tanks.” Review of
Automotive Engineering Vol. 26 (2005): 59.


Yazawa, Y., M. Muraki, et al. “Effect of Chromium Content on
Relationship Between r-value and {111} Recrystallization Texture in
Ferritic Steel.” ISIJ International Vol. 43, No. 10 (2003): 1647-1651.


Yazawa, Y., Y. Ozaki, et al. “Development of ferritic stainless steel
sheets with excellent deep drawability by {111} recrystallization texture
control.” JSAE Review No. 24 (2003): 483.





P 66
APPENDICES


ISSF Membership


COMPANY MEMBERS


Acciaierie Valbruna


Acerinox S.A.


Acesita S.A.


Aichi Steel Corporation


Arcelor Mittal


Baoshan Iron And Steel Co. (Stainless Steel Branch)


Cogne Acciai Speciali S.p.A.


Columbus Stainless (Pty) Ltd


Daido Steel Co. Ltd.


Deutsche Edelstahlwerke GmbH


Hyundai Steel Company


Industeel


JFE Steel Corporation


Jindal Stainless Ltd.


JSC Dneprospetsstal


Ningbo Baoxin Stainless Steel Co., Ltd.


Nippon Kinzoku Co., Ltd.


Nippon Metal Industry Co. Ltd.


Nippon Steel and Sumikin Stainless (NSSC)


Nippon Yakin Kogyo Co., Ltd.


Nisshin Steel Co., Ltd.


North American Stainless


Outokumpu Oyj


Panchmahal Steel Limited (PSL)


POSCO


POSCO Specialty Steel Co., Ltd.


Shanghai Krupp Stainless (SKS)


SIJ - Slovenska Industrija Jekla d.d./Slovenian Steel Group


Steel Authority of India Ltd. (SAIL)


Sumitomo Metal Industries, Ltd.


Taiyuan Iron And Steel (Group) Co. Ltd. (TISCO)


Takasago Tekko K.K.


Tang Eng Iron Works Co. Ltd.


Thainox Stainless Public Company Limited


ThyssenKrupp Acciai Speciali Terni S.p.A.


ThyssenKrupp Mexinox S.A. De C.V.


ThyssenKrupp Nirosta GmbH


Ugine & Alz


Ugitech S.A.


Viraj Group


Walsin Lihwa Corporation


Yieh United Steel Corporation (YUSCO)


Zhangjiagang Pohang Stainless Steel Co. Ltd. (ZPSS)


Affiliated Members


Australian Stainless Steel Development Association (ASSDA)


British Stainless Steel Association (BSSA)


Cedinox


CENDI


Centro Inox


Edelstahl-Vereinigung e.V.


Euro Inox


EUROFER


Institut De Développement De L’inox (ID Inox)


Informationsstelle Edelstahl Rostfrei (ISER)


Indian Stainless Steel Development Association (ISSDA)


Japan Stainless Steel Association (JSSA)


Jernkontoret


Korea Iron And Steel Association (KOSA)


New Zealand Stainless Steels Development Association (NZSSDA)


Nucleo Inox


Southern Africa Stainless Steel Development Association (SASSDA)


Special Steel And Alloys Consumers And Suppliers Association
(USSA)


Specialty Steel Industry Of North America (SSINA)


Stainless Steel Council Of China Specialist Steel Enterprises
Association (CSSC)


Swiss Inox


Taiwan Steel And Iron Industries Association (TSIIA)


Thai Stainless Steel Development Association (TSSDA)


Union De Empresas Siderúrgicas (UNESID)





P 67
Acknowledgements


ISSF is grateful to Friedriche Teroerde (ICDA) for writing the foreword
to this brochure and to Philippe Richard (Arcelor Mittal Stainless,
France), who coordinated a working group consisting of Jacques
Charles (Ugine & Alz , France), Peirteh Huang (Yusco, Taiwan,
China), Kwangyuk Kim (Posco, South Korea), Jochen Krautschick
(ThyssenKrupp Nirosta, Germany), Juan Antonio Simon (Acerinox,
Spain) and Hideaki Yamashita (JFE, Japan). Thanks also go to Benoît
Van Hecke (Euro Inox, Belgium) for checking the text and to Paul
Snelgrove, freelance consultant and English-language writer (Paris,
France), for his invaluable help in preparing the brochure.


Thanks are also due to de blauwe peer (Ghent, Belgium) for design
and production, to MBCOM (Paris, France) for designing the cover
and to Stevens Creative Printing (Merelbeke, Belgium) for printing.


PHOTO CREDITS


ISSF wishes to thank the companies and individuals who have
contributed photographs to this publication. In those cases where the
original source of a photograph used is not known, ISSF extends its
apologies to the copyright owner.


Front cover: MBCOM, Paris, France;


p. 2-3: Ugine & Alz (Arcelor Mittal Group), France;


p. 4: Columbus Stainless [Pty] Ltd, S. Africa;


p. 5: Acesita (Arcelor Mittal Group), Brazil;


p. 7: Lincat Limited, Lincoln, UK;


p. 8: ISSF China, PRC;


p. 9 (tl): BSH Bosch und Siemens Hausgerate GmbH, Munich,
Germany;


p. 9 (bl): Whirlpool Corporation, Cassinetta di Biandronno, Italy;


p. 9 (r): Groupe SEB, Rumilly, France;


p. 10: Acesita (Arcelor Mittal Group), Brazil;


p. 11 (tl): IKEA, Aelmhult, Sweden;


p. 11 (bl): Yiu Heng International Company Limited, Macao;


p. 11 (r): Takara Standard Corporation, Japan;


p. 12 (t): Acesita (Arcelor Mittal Group), Brazil;


p. 12 (b): Tramontina, São Paulo, Brazil;


p. 13 (l): Lincat Limited, Lincoln, UK;


p. 13 (r): Korea Iron & Steel Association (KOSA), Seoul, S. Korea;


p. 14: POSCO, Pohang, S. Korea;


p. 15 (l & c): Ugine & Alz (Arcelor Mittal Group), France;


p. 15 (tr): Suncue Company Ltd. and Yieh United Steel Corp.
(YUSCO), Taiwan, China;


p. 15 (br): Japan Stainless Steel Association (JSSA), Tokyo, Japan;


p. 16 (l): Southern Africa Stainless Steel Development Association
(SASSDA), Rivonia, S. Africa;


p. 16 (r): Acesita (Arcelor Mittal Group), Brazil;


p. 17: Acesita (Arcelor Mittal Group), Brazil;


P. 18 (L): Ugine & Alz (Arcelor Mittal Group), France;


P. 18 (Tr): Mac Brothers Catering Equipment, Cape Town, S. Africa;


p. 18 (br): Centro Inox and ThyssenKrupp Acciai Speciali Terni S.p.A.,
Italy;


p. 19: Acesita (Arcelor Mittal Group), Brazil;


p. 20 (t): BSH Bosch und Siemens Hausgerate GmbH, Munich,
Germany;


p. 20 (b): Faurecia, Nanterre, France;


p. 21 (l): Valtimet, Boulognebillancourt, France;


p. 21 (c): Ugine & Alz (Arcelor Mittal Group), France;


p. 21 (r): Acesita (Arcelor Mittal Group), Brazil;


p. 22 (l): Sander Inox and Nucleo Inox, Brazil;


p. 22 (r): Ompagrill and Centro Inox, Italy;


p. 23: BSH Bosch Und Siemens Hausgerate GmbH, Munich,
Germany;


p. 24 (tl & tr): Japan Stainless Steel Association (JSSA), Tokyo,
Japan;

p. 24 (br): Columbus Stainless [Pty] Ltd, S. Africa;


p. 25 (l): Korea Iron & Steel Association (KOSA), Seoul, S. Korea;


p. 25 (tc): Ugine & Alz (Arcelor Mittal Group), France;


p. 25 (tr): Faurecia, Nanterre, France;


p. 26 (t): Group SEB, Rumilly, France;


p. 26 (b): LG Electronics, S. Korea;


p. 27 (l): Columbus Stainless [Pty] Ltd, S. Africa;

p. 27 (r): Japan Stainless Steel Association (JSSA), Tokyo, Japan;


p. 28 (l): BSH Bosch Und Siemens Hausgerate GmbH, Munich,
Germany;


p. 28 (r): Korea Iron & Steel Association (KOSA), Seoul, S. Korea;


p. 29: Taiyuan Iron & Steel (Group) Company Ltd. (TISCO), Taiyuan,
PRC;


p. 30 (t): ISSF China, PRC;


p. 30 (b): Qingdao Haier International Trading Co. Ltd., PRC;


p. 31 (l): Suntank, Pretoria, S. Africa;


p. 31 (r): Japan Stainless Steel Association (JSSA), Tokyo, Japan;


p. 32 (box): POSCO, Pohang, S. Korea;


p. 33 (all): Ugine & Alz (Arcelor Mittal Group), France;


p. 34 (l): Centro Inox, Italy;


p. 34 (tr): Faurecia, Nanterre, France;


p. 34 (b): all 4 photos Ugine & Alz (Arcelor Mittal Group), France;


p. 35: Acesita (Arcelor Mittal Group), Brazil;


p. 36 (t): ThyssenKrupp Nirosta GmbH, Krefeld, Germany;


p. 36 (b): Macadams Baking Systems (Pty) Ltd, Cape Town, S. Africa;


p. 37 (l): Faurecia, Nanterre, France;


p. 37 (r): Ugine & Alz (Arcelor Mittal Group), France;


p. 38 (l): Faurecia, Nanterre, France;


p. 38 (r): Ugine & Alz (Arcelor Mittal Group), France;


p. 39 (l): Suntank, Pretoria, S. Africa;


p. 39 (tr): Acesita (Arcelor Mittal Group), Brazil;


p. 39 (br): Solaris Bus & Coach Co., Poland;


p. 40 (l):
Brandt Edelstahldach GmbH, Cologne, Germany;


p. 40 (r): Ugine & Alz (Arcelor Mittal Group), France;


p. 41 (tr): Ugine & Alz (Arcelor Mittal Group), France;


p. 41 (br): ThyssenKrupp Nirosta GmbH, Krefeld, Germany;


p. 42 (tl): Willem De Roover, Ghent, Belgium;


p. 42 (bl): Faurecia, Nanterre, France;


p. 42 (tr): Centro Inox, Milan, Italy;


p. 42 (br): Ugine & Alz (Arcelor Mittal Group), France;


p. 43: Hanjin, S. Korea;


p. 44 (t): Groupe SEB, Rumilly, France;


p. 44 (b): Lincat Limited, Lincoln, UK;


p. 58: ThyssenKrupp Nirosta GmbH, Krefeld, Germany;


p. 62: Valtimet, Boulogne-Billancourt, France;


p. 63: POSCO, Pohang, S. Korea.




DISCLAIMER


Every effort has been made to ensure that the information presented
in this publication is technically correct. However, the reader is
advised that the material contained herein is intended for general
information purposes only. ISSF, its members, staff and consultants
specifically disclaim any liability or responsibility for loss, damage or
injury resulting from the use of the information contained in this
publication (in printed, electronic or other formats).


DATE OF PUBLICATION APRIL 2007 - COPYRIGHT - ISBN 2-
930069-51-1





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