321
Type 321 is a stainless steel alloy containing chromium and nickel. It has excellent resistance to intergranular corrosion due to the addition of titanium. Compared to Type 302, Type 321 shows lower overall corrosion. It is specifically used in situations where resistance to intergranular corrosion is needed and where the components experience continuous heating or cooling between 800 and 1500ºF. Typical applications of Type 321 include exhaust stacks, manifolds, and ring collectors.
Chemical Composition Limits
| Weight% | C | Si | Mn | P+S | Cr | Ni | Ti | N | Fe | Cu | Mo |
| AMS 5510 Alloy 321 | 0.08 max | 0.25-1.00 | 2.0 max | 0.040P 0.030S | 17-19 | 9-12 | 0.7 max | 0.1 max | Bal | 0.75 max | 0.75 max |
Mechanical Properties
| Material | Condition | Tensile Strength (ksi) | Yield Strength (ksi) | % Elongation | Hardness HB |
| Alloy 321 AMS 5510 | AMS 5510 Sheet (Sol Trtd) | 70-100 | 25 | 40 | – |
| Alloy 321 AMS 5645 | AMS 5645 Bar (Sol Trtd) | – | – | – | 255 max |
Specifications
| AMS 5510 Sheet / strip / plate | AMS 5557 Welded/seamless tube |
| AMS 5559 Welded / thin wall tube | AMS 5570 Seamless tube |
| AMS 5576 Welded tube | AMS 5645 Bars / wire / forging |
| MIL-S-6721 | MIL-T-8606 Seamless tube |
| MIL-T-8606 Welded tube | MIL-T-8808 Seamless tube |
| MIL-T-8808 Welded tube | QQ-S-766 |
| ASTM A240 / ASME SA240 | ASTM A167 / ASME SA167 |
| ASTM A193 Grade B8T CL1 | ASTM A276 / ASME SA276 |
| ASTM A314 / ASME SA314 | ASTM A320 Grade B8T |
| ASTM A479 / ASME A479 | ASTM A484 / ASME SA484 |
| AISI 321 | BS 2S129 |
| BS T67 Tube | BS S524 Sheet |
| BS S526 Sheet | BS 970; 321S31 |
| EN58B | WS 1.4541 |
| Z10CnNb18-11 | UNS S32100 |