Contrary to the perception most people have, stainless
steel is not only one material, but rather many
specialty steels. There are probably over 100 different
stainless steels readily available in the North
American market, and many more that can be had if one
is willing to go through the trouble of special
ordering.
To oversimplify things, steel is an alloy of iron and carbon (steels of various types contain from 0.04 percent to 2.25% carbon);
by adding not less 10.5% chromium (by weight) to the
basic low carbon steel
the properties change drastically: it makes the steel
less prone to rust and staining (thus
"stain less").
Classification
There are three general types of classifications used to
identify stainless steels, which ultimately give the
name of a particular steel:
Corrosion resisting properties.
The chromium present within the steel structure
oxidates and allows the formation of a relatively
rough, yet invisible, protective film. This film of
corrosion-resisting chromium oxide on the steel
surface is self-healing: whenever damaged, be it
mechanically or chemically, it will regenerate itself
in the presence of oxygen. The corrosion resistance
is generally enhanced by an increased chromium content,
as well as other alloying elements such as molybdenum
and nickel.
An application to be seriously considered: metal roofs...
...such as standing seam roofs, may last well over 100 years without any major need for maintenance, repair, or replacement. Material costs on such project will vary with the size of each project; they may be as low as $1.00 per square foot for stainless steel ( about the same as for copper). Coastal applications where the salt air environment may void the traditional roof warranty are key target areas
