|MICC Sheath types||UNS Ref.||DIN Ref.|
Similar to 304 (18%Cr-10%Ni) but with Titanium added as a stabiliser.
Titanium prevents sensitisation & weld decay. 321 loses stabilising additive (Ti) during welding.
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 for engine parts, heat exchangers, exhaust stacks, rocket engines, manifolds, and etc.
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.