Stainless 321 · UNS S32100 · W. Nr. 1.4541
Stainless 321 (S32100): composition, properties, fittings and flanges
Stainless 321 (S32100, W. Nr. 1.4541) is Titanium-stabilised austenitic stainless steel. Stainless 321 is specified at Chromium 17.00 - 19.00, Nickel 9.00 - 12.00, Titanium 5 x C min to 0.70 max. 321 is stabilised with titanium so that it can be held at 425 - 815 °C without chromium carbide precipitation, making it the standard…
- UNS
- S32100
- W. Nr.
- 1.4541
- Density
- 8.00 g/cm³ (0.289 lb/in³)
- Key strength
- 515 MPa / 75 ksi
Identification and standards
| Short form | Stainless 321 · UNS S32100 · W. Nr. 1.4541 |
|---|---|
| Classification | Titanium-stabilised austenitic stainless steel |
| UNS | S32100 |
| Werkstoff number | 1.4541 |
| Material family | Stainless Steel |
Chemical composition
| Element | Composition (wt %) | Why it is there |
|---|---|---|
| Chromium (Cr) | 17.00 - 19.00 | Passive film and oxidation resistance |
| Nickel (Ni) | 9.00 - 12.00 | Austenite stability |
| Titanium (Ti) | 5 x C min to 0.70 max | Carbon stabilisation |
| Carbon (C) | 0.08 max | - |
| Manganese (Mn) | 2.00 max | - |
| Silicon (Si) | 0.75 max | - |
| Phosphorus (P) | 0.045 max | - |
| Iron (Fe) | Balance | Matrix |
Note Single figures are maximum limits unless shown as a range. Always confirm against the heat-specific EN 10204 3.1 certificate supplied with your order.
Mechanical properties
| Tensile strength, min (annealed) | 515 MPa / 75 ksi |
|---|---|
| 0.2 % yield strength, min | 205 MPa / 30 ksi |
| Elongation in 2 in, min | 40 % |
| Typical hardness, annealed | 145 - 190 HB |
| Useful continuous service temperature | About 815 °C |
Warning Values depend on product form, section thickness and heat treatment. Larger sections generally achieve lower strength than thin product; always design against the applicable code allowable stress rather than these figures.
Physical properties
| Density | 8.00 g/cm³ (0.289 lb/in³) |
|---|---|
| Melting range | 1400 - 1455 °C (2550 - 2650 °F) |
| Modulus of elasticity | 193 GPa (28.0 x 10⁶ psi) |
| Thermal conductivity at 20 °C | 16.1 W/m·K |
| Mean coefficient of thermal expansion, 20-100 °C | 16.6 µm/m·°C |
| Specific heat capacity | 500 J/kg·K |
Specifications by product form
| Forgings & flanges | ASTM A182 F321 · ASME SA-182 |
|---|---|
| Butt weld fittings | ASTM A403 WP321 · ASME SA-403 |
| Seamless pipe & tube | ASTM A312 TP321 · ASME SA-312 |
| Plate / sheet / strip | ASTM A240 321 · ASME SA-240 |
| Bar / rod | ASTM A276 / A479 |
| Welding consumables | ER321 or ER347 |
| UNS / EN / China | UNS S32100 · W. Nr. 1.4541 · GB 06Cr18Ni11Ti |
Product forms available
Hangbo supplies this grade in the following forms. Sizes outside the listed range can often be produced to order.
- Forged flanges blanks and finished flanges to ASME B16.5, B16.47 Series A/B and B16.36
- Butt weld elbows, tees, reducers, caps and stub ends to ASME B16.9 and MSS SP-43
- Seamless pipe and tube to the applicable ASTM / ASME pipe specification
- Forged rings, discs and hubs machined to your drawing
Typical applications
- Aircraft exhaust systems and expansion joints
- Refinery heater tubes and thermal oxidiser ducting
- Pressure vessels and heat exchangers held at 425 - 815 °C
- Welded heavy-section equipment that cannot be annealed
Welding, forming and machining
- Welding
- Weld with ER321 or ER347 filler. ER347 is often preferred because niobium survives the weld pool better than titanium.
- Heat treatment
- Stabilise at 870 - 900 °C, or solution anneal at 950 - 1120 °C and water quench.
- Hot and cold forming
- Hot work in the range stated by the mill for this grade, then re-solution or re-age before final machining so that the delivered condition matches the certificate.
- Machining
- Machine with sharp carbide or high-speed steel tooling, positive rake, constant feed and ample coolant. Never dwell - the surface work-hardens quickly.
Buy Stainless 321 from Hangbo
Material is supplied with full heat-number traceability, solution annealing or ageing performed under calibrated furnace control, and an EN 10204 3.1 certificate covering chemical analysis, mechanical properties, heat treatment records and the agreed NDT scope. Positive material identification and third party inspection and test reports from SGS are available for critical service.