ASTM A 240, A 479, A 276
UNS S32100
321 Stainless is available in the following forms at Mega Mex
- Stainless Steel 321 Sheet
- Stainless Steel 321 Plate
- Stainless Steel 321 Bar
- Stainless Steel 321 Pipe & Tube
- Stainless Steel 321 Fittings (i.e. flanges, slip-ons, blinds, weld-necks, lapjoints, long welding necks, socket welds, elbows, tees, stub-ends, returns, caps, crosses, reducers, and pipe nipples)
- Stainless Steel 321 Weld Wire
321 Stainless Steel Overview
Stainless 321 is a heat resistant, titanium stabilized, austenitic alloy that’s commonly used for service in the 1000°-1600°F temperature range. 321 stainless is primarily used in applications that involve continuous and intermittent service temperatures within the carbide precipitation range of 800°-1500°F. Type 321 is similar to type 304 stainless but with a titanium addition of at least five times the carbon content. This titanium addition reduces or prevents carbide precipitation during welding and in the 800°-1500°F service conditions. In order to provide optimum resistance to intergranular corrosion and to polythionic acid stress corrosion cracking in service temperatures at 1500°-1650°F an air cool may be used.
What are the characteristics of 321 Stainless?
- 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 | Cu | Ti | C | |
|---|---|---|---|---|---|---|
| MIN | 17.0 | 9.0 | – | – | 5x(C+N) | – |
| MAX | 19.0 | 12.0 | 0.75 | 0.75 | 0.70 | 0.08 |
| Mn | Si | P | S | N | Fe | |
| MIN | – | 0.25 | – | – | – | – |
| MAX | 2.0 | 1.0 | 0.04 | 0.03 | 0.1 | Bal |
What applications might 321 Stainless Steel be used?
- Aircraft piston engine manifolds and exhaust stacks
- Expansion joints
- Thermal oxidizers
- Refinery equipment
- High temperature chemical process equipment
Mechanical Properties
Average Elevated Temperature Tensile Properties
| Temperature, °F | Ultimate Tensile Strength, ksi | .2% Yield Strength, ksi |
|---|---|---|
| 68 | 84 | 38 |
| 400 | 62 | 20.5 |
| 600 | 62 | 18 |
| 800 | 62 | 17 |
| 1000 | 59.5 | 16.5 |
| 1200 | 45.5 | 16 |
| 1400 | 27.5 | 14 |
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.