Definition of stainless steel: stainless steel usually refers to
the corrosion resistance of air, water, acid, alkali salt or other
media. According to the ability of different alloy components,
attention is paid to rust prevention and acid resistance. Although
some steel rusts, it is not necessarily acid resistance. Acid steel
is usually Has anti-rust properties. All stainless steel is not one
that can cope with all corrosive environments and cannot rust.
"Stainless steel" is a wrong name, because no one can deal with all
corrosive environments and cannot rust. The real meaning of
stainless steel is just "difficult to rust".
Classification of stainless steel:
(1) According to the structure, it is divided into: martensitic
stainless steel, iron surface stainless steel, austenitic stainless
steel, duplex stainless steel;
(2) According to the main chemical composition of steel, it is
divided into: chromium nickel stainless steel, chromium nickel
molybdenum stainless steel, and ultra-low carbon stainless steel.
(For the production of fasteners, the 300 series austenitic
stainless steel is mainly used. The main chemical composition of
this stainless steel is 18% chromium and 8% nickel, which is
generally called 18-8 stainless steel, which is a chromium-nickel
stainless steel series )
(3) The characteristics of austenitic stainless steel: in the
normal state, there is no magnetism, and it is slightly magnetic
after cold processing; at different temperatures, it can maintain
its Ostian structure without phase change, so it cannot be hardened
by heat treatment; however, when applied to When cold working, it
hardens and increases strength.