| STAINLESS
STEEL OVERVIEW: FEATURES & BENEFITS
Features
General Information
The many unique values provided by stainless steel make it
a powerful candidate in materials selection. Engineers, specifiers
and designers often underestimate or overlook these values
because of what is viewed as the higher initial cost of stainless
steel. However, over the total life of a project, stainless
is often the best value option.
What is Stainless
Steel?
Stainless steel is essentially a low carbon steel which contains
chromium at 10% or more by weight. It is this addition of
chromium that gives the steel its unique stainless, corrosion
resisting properties.
The chromium content
of the steel allows the formation of a rough, adherent, invisible,
corrosion-resisting chromium oxide film on the steel surface.
If damaged mechanically or chemically, this film is self-healing,
providing that oxygen, even in very small amounts, is present.
The corrosion resistance and other useful properties of the
steel are enhanced by increased chromium content and the addition
of other elements such as molybdenum, nickel and nitrogen.
There are more
than 60 grades of stainless steel. However, the entire group
can be divided into five classes. Each is identified by the
alloying elements which affect their microstructure and for
which each is named.
Benefits of Stainless
Steel
Corrosion resistance
Lower alloyed grades resist corrosion in atmospheric and pure
water environments, while high-alloyed grades can resist corrosion
in most acids, alkaline solutions, and chlorine bearing environments,
properties which are utilized in process plants.
Fire and heat resistance
Special high chromium and nickel-alloyed grades resist scaling
and retain strength at high temperatures.
Hygiene
The easy cleaning ability of stainless makes it the first
choice for strict hygiene conditions, such as hospitals, kitchens,
abattoirs and other food processing plants.
Aesthetic appearance
The bright, easily maintained surface of stainless steel provides
a modern and attractive appearance.
Strength-to-weight
advantage
The work-hardening property of austenitic grades, that results
in a significant strengthening of the material from cold-working
alone, and the high strength duplex grades, allow reduced
material thickness over conventional grades, therefore cost
savings.
Ease of fabrication
Modern steel-making techniques mean that stainless can be
cut, welded, formed, machined, and fabricated as readily as
traditional steels.
Impact resistance
The austenitic microstructure of the 300 series provides high
toughness, from elevated temperatures to far below freezing,
making these steels particularly suited to cryogenic applications.
Long term value
When the total life cycle costs are considered, stainless
is often the least expensive material option.
Cycle of Stainless
Steel
To ensure a high quality of life, the materials that we use
as consumers and manufacturers should meet not only technical
performance standards, but have a Long Service Life, be Usable
in a Great Number of Applications, and be Environmentally
Friendly. Once their service is complete, they should be 100%
Recyclable, thereby completing the life cycle to be used once
again. Stainless Steel is such a material.
The longevity of
stainless is the result of the alloying composition and, therefore,
it has a natural corrosion resistance. Nothing is applied
to the surface that could add additional material to the environment.
It does not need additional systems to protect the base metal,
the metal itself will last.
Stainless steel
needs less maintenance and its hygienic qualities means that
we do not have to use harsh cleaners to get a clean surface.
There is little or nothing to dump into the drain that could
have an environmental impact.
Stainless steel
products complete their service life. There is less concern
about disposal since this material is 100% recyclable. In
fact, over 50% of new stainless steel comes from old remelted
stainless steel scrap, thereby completing the full life cycle.
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