Alloy 321 (UNS S32100) is titanium stabilized austenitic stainless steel plate with good general corrosion resistance. It has excellent resistance to intergranular corrosion after exposure to temperatures in the chromium carbide precipitation range of 800 - 1500°F (427 - 816°C). The alloy resists oxidation to 1500°F (816°C) and has higher creep and stress rupture properties than alloys 304 and 304L. It also possesses good low temperature toughness.
Alloy 321H (UNS S 32109) stainless steel plate is the higher carbon (0.04 - 0.10) version of the alloy. It was developed for enhanced creep resistance and for higher strength at temperatures above 1000oF (537°C). In most instances, the carbon content of the plate enables dual certification.
Alloy 321 stainless steel plate cannot be hardened by heat treatment, only by cold working. It can be easily welded and processed by standard shop fabrication practices.
Weight % (all values are maximum unless a range is otherwise indicated)
|Chromium||17.00 min.-19.00 max.||17.00 min.-19.00 max.|
|Nickel||9.00 min.-12.00 max.||9.00 min.-12.00 max.|
|Carbon||0.08||0.04 min.-0.14 max.|
|Titanium||5 x (C + N) min.-0.70 max.||4 x (C + N) min.-0.70 max.|
Typical Values at 68°F (20°C)
in 2 in.
|psi (min.)||(MPa)||psi (min.)||(MPa)||% (min.)||(max.)|
Alloy 321 stainless steel plate exhibits good general corrosion resistance that is comparable to 304. It was developed for use in the chromium carbide precipitation range of 1800 – 1500°F (427 – 816°C) where un-stabilized alloys such as 304 are subject to intergranular attack.
The alloy can be used in most diluted organic acids at moderate temperatures and in pure phosphoric acid at lower temperatures and up to 10% diluted solutions at elevated temperatures. Alloy 321 resists polythionic acid stress corrosion cracking in hydrocarbon service. It can also be utilized in chloride or fluoride free caustic solutions at moderate temperatures.
Alloy 321 stainless steel plate does not perform well in chloride solutions, even in small concentrations, or in sulfuric acid service.