321 Stainless Steel is a standard austenitic 18/8 stainless steel grade, (304), but stabilized by Titanium. The titanium within means the stainless steel is intergranular corrosion resistant after heating, (between 425-900 degrees Celsius). Remarkably high strength as well as scaling resistance and phase stability set 321 Stainless Steel apart from other similar grades. This grade is not, however, recommended for welding consumable, as the titanium component does not allow good transfer of heat across a high temperature arc.
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 312, ASME SA 479
ASTM A 240, ASTM A 276, ASTM A 276 Condition A, ASTM A 276 Condition S, ASTM A 312, ASTM A 479
EN 1.4541
GE B50T1181, GE B50T12, GE B50T81
QQS 763, QQS 766d
UNS S32100
Werkstoff 1.4541
Inventory
321 Stainless Steel Bars, 321 Stainless Steel Angle Bars, 321 Stainless Steel Flanges, 321 Stainless Steel Tubes & 321 Stainless Steel Pipe Fittings
Common Trade Names
321, 321 Stainless Steel, 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
- Stainless Steel Pipe Fittings
- Ball Valves
- Thermal oxidizers
- Refinery equipment
- Stainless Steel tubes
- Expansion joints
- High temperature chemical process equipment
Physical Properties
Density: 0.286 lb/inch3
Melting Point: 2550 - 2600°F
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 | - |
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 |
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.
Source: Yaang Pipe Industry (www.yaang.com)
