321 Stainless Steel

321 stainless steel is a variant of type 304 but with added titanium as a stabiliser (around five times the amount of carbon).

The addition of titanium improves the high-temperature performance of the alloy while reducing the effects of carbide precipitation in the heat-affected zone under welding. 321 offers improved creep strength, and corrosion resistance is excellent, particularly in chemical and oxidating atmospheres. Type 321 is more challenging to form than other austenitic grade materials, although it can be readily formed and drawn. The alloy finds extensive use in the oil & gas sector in the production of pressure vessels, boilers and heat exchangers.


Typical commercial applications include:

  • Excellent chemical & oxidation corrosion resistance
  • Stabilised with titanium
  • Good creep strength
  • Easily welded

321 stainless steel alloy finds typical use in commercial engineering applications, including pressure vessels, industrial boilers, heat exchangers and aircraft components.

About Intergranular Corrosion

Intergranular corrosion (also referred to as intergranular attack) relates to localised corrosion of grain boundaries within an alloy where most of the grain remains unaffected. While the integrity of the product is not affected by any significant material loss, the corrosion effects can prove catastrophic. Intergranular corrosion may lead to component failure in applications such as pressurised vessels or piping systems. Choosing a material grade with resistance to this type of corrosion is critical in specific applications, and 321 stainless is highly suitable.


Like the majority of austenitic stainless steels, 321 stainless is non-magnetic due to the higher inclusions of chromium and nickel.

Stock Range

We stock Type 321 stainless steel in flats, round bars sheets and plates.

321 Stainless Steel
321 Stainless pdf
321 Stock

Product Summary

Product 321
Type Austenitic Stainless Steel
Availability Flats, round bar, sheet and plate
Benefits Excellent chemical & oxidation corrosion resistance, stabilised with titanium good creep strength, easily welded
Applications Pressure vessels, industrial boilers, heat exchangers, aircraft components
Datasheet 321 - Technical Datasheet
Reference Home/ Products/ Stainless Steels/ 321

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