321 stainless steel Applications,321 stainless steel Welding
Type 321 stainless steel (UNS S32100) is an austenitic stainless steel that has fives times more titanium than carbon in its content. The increased titanium level aids in preventing carbide precipitation during welding. As a result, Type 321 is both creep resistant and resistant to oxidation.
321 stainless steel Chemical Composition
Carbon 0.08 max.
Manganese 2.00 max.
Sulfur 0.030 max.
Phosphorus 0.045 max.
Silicon 0.75 max.
Chromium 17.00 – 19.00
Nickel 9.00 – 12.00
Titanium 5x(C+N) min. – 0.70 max.
Nitrogen 0.10 max.
321 stainless steel Applications:
annealing covers, high-temperature tempering equipment, diesel and heavy duty automotive exhaust systems, firewalls, stack liners, boiler casings, welded pressure vessels, jet aircraft components, radiant super heaters, bellows and oil refinery equipment
321 stainless steel Processing:
Type 321 is non-hardenable by heat treatment. Annealing: Heat to 1750 - 2050°F, then water quench or air cool. Forming: Type 321 can be readily formed and drawn. Like most austenitic stainless steels, Type 321 work hardens and may require annealing after severe forming.
321 stainless steel Welding:
This particular alloy is generally considered to have comparable weldability to Types 304 and 304L. A major difference is the titanium addition that reduces or prevents carbide precipitation during welding. When a filler is needed, either AWS E/ER 347 or E/ER 321 is most often specified.
321 stainless steel Corrosion:
Type 321 exhibits excellent resistance to organic chemicals, dyestuffs, and a wide range of inorganic chemicals. It resists nitric acid well and the sulfur acids moderately. Long-time exposure in the 900 -1500°F range may lower its general corrosion resistance, but the grade still shows improved resistance to intergranular corrosion compared to unstabilized grades.