Stainless steel 

To put it simply, stainless steel is not easy to rust steel, in fact, a part of stainless steel, both rust, and acid (corrosion resistance).Stainless steel's rust and corrosion resistance are due to the composition of a chrome-rich oxide film (passivation film) on its surface.This rust resistance is relative to corrosion resistance.The experimental results show that the corrosion resistance of steel in the atmosphere, water and other weak medium and nitric acid oxidation medium, with the addition of chromium water content in steel and progress, when the chromium content reached a certain percentage, steel corrosion resistance attack sudden change, that is, from easy to rust to rust, not corrosion resistance to corrosion.There are many ways to classify stainless steel.According to the arrangement structure classification at room temperature, there are martensite, austensite, ferrite and duplex stainless steel;According to the primary chemical composition classification, basically can be divided into chromium stainless steel and chromium nickel stainless steel two systems;According to the use of stainless steel nitric acid resistance, resistance to sulfuric acid stainless steel, seawater resistance stainless steel, etc., according to the type of corrosion resistance can be divided into pitting stainless steel, stress corrosion resistance stainless steel, intercrystalline corrosion resistance stainless steel;According to function characteristic classification can be divided into non-magnetic stainless steel, free cutting stainless steel, low temperature stainless steel, high strength stainless steel and so on.Because stainless steel has outstanding corrosion resistance, formability, compatibility and in a very wide range of temperature in the strong patience and other series of characteristics, so in heavy industry, light industry, daily necessities occupation and building decoration and other occupations to obtain a wide range of applications.Austenitic stainless steel having an austenitic arrangement at room temperature.Steel with Cr about 18%, Ni 8%~10% and C about 0.1% has stable austenite arrangement.Austenitic chrome-nickel stainless steel contains the famous 18cr-8ni steel and on this basis, the addition of Cr, Ni content and participate in Mo, Cu, Si, Nb, Ti and other elements developed by the high cr-ni series of steel.Austenitic stainless steel is non-magnetic and has high resistance and plasticity, but the strength is low, it can not be strengthened through phase change, can only be strengthened through cold processing.Such as S, Ca, Se, Te and other elements, it has excellent cutting.This kind of steel in addition to oxidation resistance acid medium corrosion, if the element such as Mo, Cu also ability sulfuric acid, phosphoric acid and, acetic acid, urea corrosion.If the carbon content of this kind of steel is less than 0.03% or contains Ti and Ni, its intercrystalline corrosion resistance can be significantly improved.High silicon austenitic stainless steel has excellent corrosion resistance.Because of its comprehensive and outstanding induction function, austenitic stainless steel has been widely used in all walks of life. 

A versatile stainless steel widely used for making equipment and parts that require a good combination of corrosion resistance and formability.Can withstand general corrosion in the building, can resist food processing media erosion (but contains strong acid and chloride components at high temperatures may occur corrosion), can resist organic compounds, dyes and a wide variety of inorganic compounds.Type 304L (low carbon), good nitric acid resistance, and durable medium temperature and concentration of sulfuric acid, widely used as liquid gas tank, low temperature equipment (304N), appliances and other consumer products, kitchen equipment, hospital equipment, transport, waste water treatment equipment.304 is a versatile stainless steel widely used to make equipment and parts that require good overall performance (corrosion resistance and formability).

304L is a variant of 304 stainless steel with a lower carbon content. It is used where welding is required. The lower carbon content minimizes the carbides precipitated in the heat-affected zone near the welding seam.