Stainless type 302 may be said to be the original 18/8 stainless steel. It is an austenitic stainless steel for safe continuous use up to 1600 ºF (870ºC) and is resistant to atmospheric corrosion and a wide range of inorganic chemicals.
Type 302 stainless is used in a wide variety of forms such as wire for applications such as springs and cables, and as flat-rolled material for a whole range of kitchen ware and hospital equipment. It is used for forged parts where its strength, toughness and corrosion resisting properties render its use appropriate.
Much higher forging pressures are required than for carbon and low alloy steels. The stock to be forged should be heated to 2100/2300ºF (1150/1260ºC) and not forged below 1700ºF (925ºC.) Parts may be air cooled with no danger of cracking and for maximum corrosion resistance parts should be annealed after forging.
The only heat treatment performed on this grade of stainless steel, as with all austenitic stainless steels, is that of annealing. The material should be annealed at 1850/2050ºF (1010/1120ºC) and water quenched. Type 302 should not be subjected to temperatures between 800/1650ºF (425/900ºC), nor slowly cooled through that range, to prevent the occurrence of intergranular corrosion.
Stainless type 302 produces long, gummy chips, so the use of chip curlers and breakers is recommended. The material work hardens rapidly, so good feeds and slow speeds tend to improve machinability, as does the use of small amounts of cold reduction on work pieces.
Type 302 stainless may be readily welded by the shielded fusion and resistance welding processes. Oxyacetylene welding is not recommended due to the danger of carbon pick up in the weld. If a filler metal is required a type 308 is recommended, and post weld annealing is recommended to prevent intergranular corrosion. Type 302 welds normally have good toughness.