Alloy 321 (UNS S32100) is stabilized stainless steel plate which offers as its main advantage an excellent resistance to intergranular corrosion following exposure to temperatures in the chromium carbide precipitation range from 800 to 1500°F (427 to 816°C). Alloy 321 stainless steel plate is stabilized against chromium carbide formation by the addition of titanium.
Alloy 321 stainless steel plate is also advantageous for high temperature service because of its good mechanical properties. Alloy 321 stainless steel plate offers higher creep and stress rupture properties than Alloy 304 and, particularly, Alloy 304L, which might also be considered for exposures where sensitization and intergranular corrosion are concerns.