321 is a titanium stabilized austenitic chromium-nickel stainless steel developed to provide an 18-8 type alloy with improved intergranular-corrosion resistance.Because titanium has a stronger affinity for carbon than chromium, titanium carbide tends to precipitate randomly within the grains instead of forming continuous patterns at the grain boundaries. 321 should be considered for applications requiring intermittent heating between 8009F (427°C) and 1650°F (899°C)
Alloy |
% |
Ni |
Cr |
Fe |
N |
C |
Mn |
Si |
S |
P |
Ti |
321 |
Min. |
9 |
17 |
balance |
5*(C+N) | ||||||
Max. |
12 |
19 |
0.1 | 0.08 | 2.0 | 0.75 | 0.03 | 0.045 | 0.70 |
Denstiylbm/in^3 | Coefficient ofThermal Expansion (min/in)-°F | Thermal Conductivity BTU/hr-ft-°F | Specific Heat BTU/lbm -°F | Modules of Elasticity (annealed)^2-psi | |
---|---|---|---|---|---|
at 68 °F | at 68 – 212°F | at 68 – 1832°F | at 200°F | at 32 – 212°F | in tension (E) |
0.286 | 9.2 | 20.5 | 9.3 | 0.12 | 28 x 10^6 |
Grade | Tensile Strength ksi |
Yield Strength 0.2% Offset ksi |
Elongation - % in 50 mm |
Hardness (Brinell) |
---|---|---|---|---|
321 | ≥75 | ≥30 | ≥40 | ≤217 |
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, QQS 763, QQS 766d, UNS S32100, Werkstoff 1.4541
• Oxidation resistant to 1600°F
• Stabilized against weld heat affected zone (HAZ) intergranular corrosion
• Resists polythionic acid stress corrosion cracking
• Aircraft piston engine manifolds
• Expansion joints
• Firearms production
• Thermal oxidizers
• Refinery equipment
• High temperature chemical process equipment