321/321H Stainless Steel
Type 321 is an electric-furnace processed austenitic stainless steel. It is non-heat treatable and non-magnetic in the annealed condition. This alloy contains 18% chromium, 8% nickel and a substantial addition of titanium. The titanium forms insoluble and stable carbide, which ties up all the carbon in the alloy and therefore prevents it from precipitating as chromium carbides. This leaves the chromium in solution to resist corrosion to a very high degree. This is extremely beneficial in applications of temperatures ranging from 800° F, to 1600° F., as it eliminates the necessity for re-annealing after fabrication.
Type 321 is used principally for applications involving welding or sustained elevated temperature operations where re-annealing is not practical, It is used extensively in the aircraft and missile industries.
This alloy is extremely resistant to intergranular corrosion and has very good corrosion resistance in weld areas. It has slightly less corrosion resistance to atmospheric conditions than Type 302 or Type 304 in the annealed condition.