The corrosion resistance of stainless steel depends on the alloy elements in the steel. The basic elements of the stainless steel and nickel, molybdenum, titanium, niobium, copper, nitrogen, etc., in order to meet the needs of the various uses of stainless steel structure and performance. So easy to be chlorine ion corrosion, because the chromium, nickel, chloride is collocated essences and collocated essences will swap assimilated and forming of stainless steel corrosion.