Stainless Steel 321
- UNS S32100
- ASTM A 240, A 479, A 276, A 312
- AMS 5510, AMS 5645
- ASME SA240, SA276, SA312, SA479
- QQS 763, 766D
- EN 1.4541, Werkstoff 1.4541
321 Stainless product forms available at Mega Mex
- Sheet
- Plate
- Bar
- Pipe & Tube
- Flanges
- Fittings
- Elbows, tees, stub-ends, returns, caps, crosses, reducers, pipe nipples. etc.
- Weld Wire (AWS Classifications: ER347, ER321 and E347, E321)
321 Stainless Steel Overview
A titanium stabilized austenitic stainless steel, 321 stainless, offers excellent resistance to intergranular corrosion post exposure to temperatures in the chromium carbide precipitation range (800 – 1500°F, 427 – 816°C).
The combination of this alloy being stabilized against chromium carbide formation and its good mechanical properties make 321 stainless advantageous for high temperature service. 321 has higher creep and stress rupture properties than 304 and 304L. 321 is commonly used for applications with prolonged service in the 800 – 1500°F temperature range.
Characteristics of 321 Stainless Steel
- Oxidation resistant to 1600°F
- Stabilized against weld heat affected zone (HAZ) intergranular corrosion
- Resists polythionic acid stress corrosion cracking
Stainless 321 Chemical Composition, %
| Cr | Ni | Mo | Ti | C | Mn | Si | P | S | N | Fe | |
|---|---|---|---|---|---|---|---|---|---|---|---|
|
MIN |
17.0 |
9.0 |
- |
5x(C+N) |
- |
- |
0.25 |
- |
- |
- |
- |
|
MAX |
19.0 |
12.0 |
0.75 |
0.70 |
0.08 |
2.0 |
1.0 |
0.045 |
0.03 |
0.1 |
Bal |
What applications use 321 Stainless Steel?
- Aircraft piston engine manifolds
- Expansion joints
- Thermal oxidizers
- Refinery equipment
- High temperature chemical process equipment
- Food Processing
Mechanical Properties
Average Elevated Temperature Tensile Properties
| Temperature, °F | Ultimate Tensile Strength, ksi | .2% Yield Strength, ksi |
|---|---|---|
|
68 |
93.3 |
36.5 |
|
400 |
73.6 |
36.6 |
|
800 |
69.5 |
29.7 |
|
1000 |
63.5 |
27.4 |
|
1200 |
52.3 |
24.5 |
|
1350 |
39.3 |
22.8 |
|
1500 |
26.4 |
18.6 |
Welding Stainless Steel 321
321 Stainless is readily welded by all common methods including submerged arc. Appropriate weld fillers are most often specified as AWS E/ER 347 or E/ER 321.
This alloy is generally considered to have comparable weldability to 304 and 304L stainless with the main difference being the titanium addition which reduces or prevents carbide precipitation during welding.