the definition of stainless steel
 Stainless steel is stainless steel and acid-resistant steel or collectively referred to is in the air and fresh water or chemical corrosion in the medium a corrosion resistant high alloy steel, stainless steel is not easy to rusty steel. The stainless steel and corrosion resistance of the surface as a result of its rich in chromium (Cr, the corresponding elements in this article see Note 1) oxide film (passive film) is formed. This stainless steel and corrosion resistance is relative. Tests showed: that steel in the atmosphere, water and weak nitric acid medium of media, such as oxidation, the corrosion resistance of steel with chromium content increases, when the chromium content of up to a certain percentage, the steel corrosion resistance mutations , that is, from easy to difficult rust , corrosion resistance to corrosion never. Stainless steel in order to maintain the inherent corrosion resistance, stainless steel must contain more than 12 % chromium.