Corrosion Resistance of Various Stainless Steel Pipe

304 is a versatile stainless steel that is widely used to make equipment and parts that require good comprehensive properties (corrosion resistance and formability).
301 stainless steel shows an obvious work hardening phenomenon during deformation and is used on various occasions requiring higher strength.
302 stainless steel is essentially a variant of 304 stainless steel with a higher carbon content. It can achieve higher strength through cold rolling.
302B is a stainless steel with a high silicon content, which has high resistance to high-temperature oxidation.
303 and 303Se are free-cut stainless steels containing sulfur and selenium respectively. They are used in situations where easy cutting and high surface brightness are mainly required.
303Se stainless steel is also used to make parts that require hot heading because, under such conditions, this stainless steel has good hot workability.
304L is a variant of 304 stainless steel with a lower carbon content and is used where welding is required. The lower carbon content minimizes the precipitation of carbides in the heat-affected zone close to the weld, and the precipitation of carbides may cause intergranular corrosion (welding erosion) of stainless steel in certain environments.
304N is a nitrogen-containing stainless steel. Nitrogen is added to improve the strength of the steel.
305 and 384 stainless steel contain high nickel and have low work hardening rates, making them suitable for various occasions that require high cold formability.
308 stainless steel is used to make welding rods.
309, 310, 314 and 330 stainless steel have relatively high nickel and chromium content to improve the oxidation resistance and creep strength of the steel at high temperatures. 30S5 and 310S are variants of 309 and 310 stainless steel. The only difference is that the carbon content is lower to minimize the precipitation of carbides near the weld. 330 stainless steel has particularly high resistance to carburization and thermal shock resistance.
Types 316 and 317 stainless steel contain aluminum, so their resistance to pitting corrosion in marine and chemical industrial environments is much better than that of 304 stainless steel. Among them, the variants of 316 stainless steel include low-carbon stainless steel 316L, nitrogen-containing high-strength stainless steel 316N, and free-cutting stainless steel 316F with a high sulfur content.
321, 347, and 348 are stainless steels stabilized with titanium, niobium plus tantalum, and niobium respectively. They are suitable for welding components used at high temperatures. 348 is a stainless steel suitable for the nuclear power industry and has certain restrictions on the combined amount of tantalum and cobalt.