The content of alloying elements. Generally speaking, steel with a chromium content of 10.5% is not easy to rust. The higher the content of chromium and nickel, the better the corrosion resistance. For example, the content of nickel in 304 material is 8-10%, and the content of chromium is 18-20%. In general, such stainless steel will not rust.

Stainless steel refers to the steel resistant to weak corrosive media such as air, steam and water and chemical corrosive media such as acid, alkali and salt, also known as stainless and acid resistant steel. The corrosion resistance of stainless steel depends on the alloy elements contained in the steel.

Surface treatment is a process that uses the marginal new technologies of modern physics, chemistry, metallurgy, heat treatment and other disciplines to change the condition and properties of the surface of parts to meet the predetermined performance requirements.

To accurately identify 304 stainless steel materials, we must do the composition analysis of metal materials. It involves internal sampling of metal materials, sample melting, chemical analysis of the content of various metal elements in steel, and finally judge whether it is really 304 stainless steel through the national standard.