Stainless
steel is not a single alloy, but rather the name applies to a group
of iron-based alloys containing a minimum of 10.5% chromium. Other
elements are added and the chromium content increased to improve the
corrosion resistance and heat-resisting properties, enhance
mechanical properties, and / or improve fabricating characteristics.
There are over 50 stainless-steel grades that were originally
recognized by the American Iron and Steel Institute (AISI.) Three
general classifications are used to identify stainless steel. Among
alloy types, “304” is the basic chromium-nickel
austenitic stainless steel and has been found suitable for a wide
range of applications. It is the most readily available in a variety
of product forms. This grade is easy to form and fabricate with
excellent resistance to corrosion.
3. Cleaning
of Stainless Steel
Stainless
steel need not be cleaned for aesthetic considerations and to
preserve corrosion resistance. Stainless steel is protected from
corrosion by a thin layer of chromium oxide. Oxygen from the
atmosphere combines with the chromium in the stainless steel to form
this passive chromium oxide film that protects from further
corrosion. Any contamination of the surface by dirt, or other
materials, hinders this passivation process and traps corrosive
agents, reducing corrosion protection. Thus, some form of routine
cleaning is necessary to preserve the appearance and integrity of the
surface.
Stainless
steels are easily cleaned by many different methods. They actually
thrive with frequent cleaning, and, unlike some other materials, it
is impossible to “wear out” stainless steel by excessive
cleaning. The effect of surface / pattern roughness, grain / pattern
orientation, and designs that allow for maximum rain cleaning
(exterior applications) should be considered.
