Stainless steel (Stainless Steel) refers to the resistance of air, steam, water and other corrosive medium and weak acid, alkali, salt and other chemical etching medium corrosion of steel, also known as acid-resistant stainless steel. Practical applications, often the weak corrosion resistance as stainless steel, corrosion medium, while the resistance to chemical corrosion of steel known as acid-resistant steel. As the two differences in the chemical composition, the former necessarily resistant to chemical corrosion, while the latter are generally of a stainless steel. Corrosion resistance of stainless steel depends on the alloying elements contained. Stainless basic alloying elements nickel, molybdenum, titanium, niobium, copper, nitrogen, etc., to meet the various uses of stainless steel organization and performance requirements. Stainless steel is easy to chloride ion etching, as chromium, nickel, chlorine elements of the same position, with the position of the original elements may be interchanged to form a corrosion of stainless steel assimilation.