In layman's terms, steel, stainless steel is not easy to rust is actually part of  Welding Electrode, both stainless steel, and acid resistance (corrosion resistance). Stainless steel and corrosion resistance of stainless steel is due to the formation of chromium-rich oxide film on its surface (passivation film). This stainless steel and corrosion resistance is relative. The tests showed that the steel in the air, water and other weak medium and nitric oxide medium, the corrosion resistance increased with the increase of chromium content in the steel, when the chromium content up to a certain percentage of the steel corrosion resistance mutation rust from easy to easy to rust, never corrosion resistance to corrosion. The classification of stainless steel. Classification of the organizational structure at room temperature, martensitic, austenitic, ferritic and duplex stainless steel, chromium stainless steel and chrome-nickel stainless steel, two systems can basically be divided; by major chemical composition; according to the zoning There are stainless steel resistant to nitric acid, resistance to sulfuric acid stainless steel and seawater-resistant Stainless Steel Electrode， corrosion resistant types of points can be divided into the pitting resistance of stainless steel, stress corrosion resistance of stainless steel, the resistance to intergranular corrosion of stainless steel; classified according to functional characteristics can be divided into non-magnetic stainless steel, free cutting steel, low-temperature stainless steel, high strength stainless steel, and so on. Because stainless steel has excellent corrosion resistance, formability, compatibility, as well as strength and toughness in a wide temperature range, such as a series of characteristics, access to widely used in heavy industry, light industry, daily industry as well as architectural decoration industry . ,