Stainless Steel refers to the steel which is resistant to weak corrosive media such as air, steam, water and chemical corrosive media such as acid, alkali and salt, also known as stainless acid-resistant steel. In practical application, steel resistant to weak corrosion medium is often called stainless steel, while steel resistant to chemical corrosion medium is called acid-resistant steel. Because of the difference in chemical composition, the former is not necessarily resistant to chemical medium corrosion, while the latter is generally stainless. The corrosion resistance of stainless steel depends on the alloying elements contained in the steel. The basic alloying elements of stainless steel include nickel, molybdenum, titanium, niobium, copper and nitrogen to meet the requirements of the structure and properties of stainless steel for various uses. Stainless steel is easy to be corroded by chloride ion, because chromium, nickel and chlorine are isotopes, which can be exchanged and assimilated to form corrosion of stainless steel.
Stainless steel case is the most common material in wrist watch. The cost of using stainless steel as the case is relatively low and the color is beautiful.