321
321 stainless is a titanium stabilized grade commonly used for service in the 1000-1600°F temperature range. For service temperatures up to about 1600°F, a stabilizing treatment at 1550-1650°F, air cool, may be used to provide optimum resistance to intergranular corrosion and to polythionic acid stress corrosion cracking.
321 stainless is readily welded by all common methods including submerged arc. Appropriate weld fillers are AWS ER347 bare wire and E347 covered electrodes. 321 stainless is similar in machinability to 304 stainless steel. It has a machinability rating of 45% relative to AISI B1112.
Chemistry
| Cr | Ni | Mo | Cu | 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 | 0.75 | 0.7 | 0.08 | 2.0 | 1.0 | 0.04 | 0.03 | 0.1 | Balance |
Specifications
AMS 5510, AMS 5645
ASME SA 240, ASME SA 479
ASTM A 240, ASTM A 276, ASTM A 276 Condition A, ASTM A 276 Condition S, ASTM A 479
EN 1.4541
GE B50T1181, GE B50T12, GE B50T81
QQS 763, QQS 766d
UNS S32100
Werkstoff 1.4541
Inventory
321 Coil, 321 Plate, 321 Sheet
Common Trade Names
321, 321 Stainless, Alloy 321
Features
- Oxidation resistant to 1600°F
- Stabilized against weld heat affected zone (HAZ) intergranular corrosion
- Resists polythionic acid stress corrosion cracking
Applications
- Aircraft piston engine manifolds
- Expansion joints
- Thermal oxidizers
- Refinery equipment
- High temperature chemical process equipment
Physical Properties
Density: 0.286 lb/inch3
Melting Point: 2550 - 2600°F
| Temperature, °F | 200 | 400 | 800 | 1000 | 1200 | 1400 | 1600 |
| Coefficient* of Thermal Expansion, in/in°F x 10-6 | 9.3 | 9.4 | 10.0 | 10.3 | 10.6 | 10.9 | 11.1 |
| Thermal Conductivity Btu • ft/ft2 • hr • °F |
8.8 | 9.7 | 11.4 | 12.1 | - | - | - |
| Modulus of Elasticity, Dynamic psi x 106 | 28.0 | 26.5 | 23.8 | 22.5 | 21.2 | 19.7 | - |
Electrical Resistivity
| Temperature, °F | 68 | 212 | 392 | 752 | 1112 | 1472 | 1652 |
| ohm circ mil/ft | 430 | 470 | 515 | 600 | 670 | 725 | 760 |
* 70°F to indicated temperature.
Mechanical Properties
Average Elevated Temperature Tensile Properties
| Temperature, °F | 68 | 400 | 600 | 800 | 1000 | 1200 | 1400 |
| Ultimate Tensile Strength, ksi | 84 | 62 | 62 | 62 | 59.5 | 45.5 | 27.5 |
| 0.2% Yield Strength, ksi | 38 | 20.5 | 18 | 17 | 16.5 | 16 | 14 |
Average Stress for Rupture
| Temperature, °F | 1050 | 1100 | 1150 | 1200 | 1250 | 1300 | 1350 | 1400 | 1450 | 1500 |
| 1,000 hours, ksi | - | 30 | - | 19 | - | 11.2 | - | 6.8 | - | 4.0 |
| 10,000 hours, ksi | 31 | 23.5 | 17.3 | 12.9 | 9.7 | 7.2 | 5.4 | 4.0 | 3.05 | 2.3 |
| 100,000 hours, ksi | 23 | 16.5 | 12 | 8.7 | 6.3 | 4.6 | 3.3 | 2.45 | 1.75 | 1.27 |
Average Stress for Secondary (minimum) Creep Rate
| Temperature, °F | 1050 | 1100 | 1150 | 1200 | 1250 | 1300 | 1350 | 1400 | 1450 | 1500 |
| 1% in 1,000 hours, ksi | 30 | 20 | 13.1 | 8.8 | 5.8 | 3.85 | 2.55 | 1.7 | 1.13 | 0.75 |
| 1% 100,000 hours, ksi | 13.6 | 9.2 | 5.9 | 3.9 | 2.55 | 1.7 | 1.1 | 0.74 | 0.48 | 0.32 |