One, 304, 316 these names are "imported" address, the label number of the national standard is more cumbersome so less used.According to the corrosion resistance of common stainless steel models to queue, roughly this is an inequality: 316>304>202>201>430>420.

Two, the chromium content in stainless steel is about 13%--18%, nickel content is about 8%--11%, these two kinds of metal elements in the corrosion medium has a high corrosion resistance, so stainless steel generally does not occur oxidation reaction (rust).

As the name suggests, stainless steel is stainless steel, here "stainless" is relative, not absolute is relative to carbon steel.Stainless steel is not easy to rust, but not absolutely not rust, just in the same condition and environment, is not easy to corrosion and rust than carbon steel.Rusting its essence is corrosion or called rust, is due to the surface of iron and steel and the atmosphere of oxygen, water and its acid, alkali, salt and other substances chemical action or electrochemical action caused by discoloration or corrosion is called rust, the surface of the material produced is rust is the oxide of iron.