321 stainless steel is made by adding titanium element on the basis of 304 composition. Its properties are very similar to 304 stainless steel. Titanium has excellent resistance to acid and alkali corrosion. When added to stainless steel, only about 1% is needed to greatly improve the rust resistance.

Austenitic stainless steel is prone to sensitization when exposed to temperatures ranging from 450°C to 850°C. During each process, carbides (mainly C23C6 chromium carbide) precipitate along grain boundaries and twin boundaries, and the neighborhoods of these boundaries of alloying elements are destroyed. In a specific corrosion environment, intergranular corrosion occurs. .

Due to the addition of stabilizing element titanium, 321 can resist the formation of chromium carbide at a temperature of 426°C~815°C, so it has better intergranular corrosion resistance and high temperature performance, and has higher creep resistance than 304 and 304L and stress-rupture properties.

In addition, 321 also has good low temperature toughness and excellent formability and welding characteristics, no need for annealing after welding.

321 stainless steel application scene

The addition of titanium in 321 makes it more suitable for high temperature applications, suitable for applications where 304 has sensitization and 304L has insufficient high temperature strength. Typical applications of 321 stainless steel plate and stainless steel tube products: thermal expansion joints, bellows, aircraft exhaust system components, heating element sheath tubes, furnace body components and heat exchangers, etc.