304 is a versatile stainless steel, which is widely used to make equipment and parts that require good overall performance (corrosion resistance and formability). 301 stainless steel exhibits obvious work hardening during deformation, and is used in various occasions requiring higher strength. 302 stainless steel is essentially a variant of 304 stainless steel with higher carbon content, which can be made to obtain higher strength through cold rolling. 302B is a kind of stainless steel with high silicon content in Heilongjiang Stainless Steel Pipe Factory, which has high resistance to high temperature oxidation. 303 and 303Se are free-cutting stainless steels containing sulfur and selenium, respectively, and are used in occasions that mainly require free cutting and high surface gloss. 303Se stainless steel is also used to make parts that require hot upsetting, because under such conditions, this stainless steel has good hot workability. 304L is a variant of 304 stainless steel with lower carbon content and is used where welding is required. The lower carbon content minimizes the precipitation of carbides in the heat-affected zone near the weld, and the precipitation of carbides may cause stainless steel to produce intergranular corrosion (welding erosion) in certain environments. 304N is a nitrogen-containing stainless steel in Heilongjiang Stainless Steel Pipe Factory. Nitrogen is added to increase the strength of the steel.