321/321H Stainless Steel Plate – High-Temperature

Corrosion Resistance

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.

 

Chemical Analysis

Weight % (all values are maximum unless a range is otherwise indicated)

Element	321	321H
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.
Manganese	2.00	2.00
Phosphorus	0.045	0.045
Sulfur	0.03	0.03
Silicon	0.75	0.75
Titanium	5 x (C + N) min.-0.70 max.	4 x (C + N) min.-0.70 max.
Nitrogen	0.10	0.10
Iron	Balance	Balance