321

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

 CrNiMoCuTiCMnSiPSNFe
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 5510AMS 5645
ASME SA 240ASME SA 312ASME SA 479
ASTM A 240ASTM A 276ASTM A 276 Condition AASTM A 276 Condition SASTM A 312ASTM A 479
EN 1.4541
GE B50T1181GE B50T12GE B50T81
QQS 763QQS 766d
UNS S32100
Werkstoff 1.4541

Inventory

321 Coil, 321 Plate, 321 Round Bar, 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