In the air or chemically corrosive media can resist corrosion of a high-alloy steel, stainless steel is a kind of steel with beautiful surface and good corrosion resistance, without having to go through color plating and other surface treatment, and play the inherent surface properties of stainless steel, used in many aspects of the steel, usually called stainless steel. The representative performance of 13 chromium steel, 18-chromium-nickel steel and other high-alloy steel.

From the metallographic point of view, because stainless steel contains chromium and the surface of the formation of a very thin chromium film, this film separates the invasion of oxygen with the steel to play a role in corrosion resistance.

In order to maintain the inherent corrosion resistance of stainless steel, steel must contain more than 12% of chromium.