AISI 321 (UNS S32100) Supplier | Bar, Tube, Plate - Hangbo Alloy
Date: 2025年11月20日 Categories: Stainless Steel Views: 368
Shanghai Hangbo Alloy Group Co., Ltd. is an ISO 9001:2015 certified manufacturer and global supplier of AISI 321 stainless steel (UNS S32100 / EN 1.4541 / GB 06Cr18Ni11Ti) round bars, plates, sheets, strips, seamless and welded tubes, pipes, forgings and wire. As the titanium-stabilized 18/8 austenitic grade, 321 resists intergranular corrosion in the 430–850°C sensitization range and retains creep strength at high temperature — the standard material for aircraft exhaust, jet-engine components, boiler and thermal-processing equipment.
Standards
- ASTM A240 / A240M — Plate, Sheet, Strip
- ASTM A276 — Bar, Rod, Shapes
- ASTM A312 / A213 — Seamless & Welded Pipe / Tube
- ASTM A182 / A182M — Forgings & Flanges
- ASME SA240 / SA276 / SA312
- UNS S32100 / EN 1.4541 / DIN X6CrNiTi18-10 / GB 06Cr18Ni11Ti
Precise ASTM Chemical Composition (%)
| Element | Range / Max |
|---|---|
| Chromium (Cr) | 17.0 – 19.0 |
| Nickel (Ni) | 9.0 – 12.0 |
| Titanium (Ti) | 5 × (C+N) min – 0.70 max |
| Carbon (C) | 0.08 max |
| Manganese (Mn) | 2.0 max |
| Silicon (Si) | 0.75 max |
| Phosphorus (P) | 0.045 max |
| Sulfur (S) | 0.030 max |
| Nitrogen (N) | 0.10 max |
Physical & Mechanical Properties
| Property | Typical Value (Min) |
|---|---|
| Tensile Strength (Annealed, ASTM A240) | 515 MPa (75 ksi) |
| Yield Strength (0.2% Offset) | 205 MPa (30 ksi) |
| Elongation (in 2") | 40% |
| Hardness | ≤ 217 HB / ≤ 95 HRB |
| Density | 8.0 g/cm³ |
| Melting Range | 1400 – 1425 °C |
| Max Continuous Service | ≈ 815 – 870 °C |
| Max Intermittent Service | ≈ 900 °C |
Depth Characteristics
- Titanium Stabilization: Ti binds carbon as stable TiC, preventing chromium-carbide precipitation and intergranular corrosion in the 430–850°C sensitization range.
- High-Temperature Creep Strength: Superior creep and rupture strength from 550–900°C for boiler, superheater and exhaust applications.
- No Post-Weld Heat Treatment: Stabilized structure permits welding without subsequent solution annealing in most service conditions.
- Thermal Cycling Endurance: Maintains integrity under repeated heating and cooling, ideal for aircraft and process equipment.
- Good Formability & Weldability: Comparable fabricability to 304 with weldability across all standard processes.
Manufacturing Process — Melting & Rolling
321 is melted in EAF and refined by AOD with precise control of titanium addition (added late in refining to maximize recovery) and carbon/nitrogen balance. Slabs are continuously cast, hot-rolled, then solution annealed at 950–1120°C and water quenched. The final anneal keeps titanium carbide finely distributed while the matrix stays fully austenitic. Plate and strip are pickled and passivated; bars are annealed, peeled and straightened; tubes are cold-pilgered and bright annealed for consistent high-temperature properties.
Testing & Inspection Methods — 100% PMI / UT
- PMI (Positive Material Identification): 100% XRF verification of Cr, Ni and Ti on every heat before dispatch.
- UT (Ultrasonic Testing): Full-length ultrasonic examination of bar per ASTM A388/E2375 where specified.
- Mechanical & Chemical: Tensile and hardness per ASTM A370/A240; chemical analysis per ASTM E353 with EN 10204 3.1 certificates.
- Plus: intergranular corrosion test (ASTM A262 Practice E), ferrite measurement, and 100% dimensional inspection.
High-Frequency Application Scenarios
- Aerospace: Aircraft exhaust manifolds, engine cowlings, anti-icing ducts and combustion components.
- Boilers & Pressure Vessels: Superheater tubes, boiler shells and headers operating in the creep range.
- Petrochemical: Furnace components, pyrolysis coils and thermal-oxidizer internals.
- Chemical Processing: Equipment exposed to 430–850°C where sensitization would attack unstabilized grades.
- Food & Thermal Cycling: Processing and drying equipment subject to repeated heating.
6+ Professional FAQs
1. Why is titanium added to 321?
Titanium (5 × C+N min) preferentially forms stable TiC, keeping chromium in solution and preventing intergranular corrosion during 430–850°C exposure.
2. How does 321 compare with 304?
321 is the stabilized high-temperature version: use it where service spans the 430–850°C sensitization range or where creep strength above 550°C is required.
3. How does 321 compare with 316?
Choose 321 for high-temperature and thermal-cycling service; choose 316 when chloride pitting resistance is the priority. 321 does not contain molybdenum.
4. Is post-weld heat treatment required?
For most applications, no — the titanium stabilization avoids sensitization in the heat-affected zone. Heavy-section or critical service should follow the applicable code requirements.
5. What is the maximum service temperature of 321?
Approximately 815–870°C continuous and up to about 900°C intermittent, limited by oxidation and scaling.
6. Which product forms are available?
Round bar, plate, sheet, strip, seamless and welded tube/pipe, forgings, flanges and wire — with EN 10204 3.1 certificates and full traceability.
Supply List
- Round Bar: Φ6mm – Φ500mm, peeled / ground
- Plate / Sheet: Thickness 0.3mm – 120mm, cut-to-size
- Seamless Tube: OD 6mm – 219mm
- Welded Pipe: OD 19mm – 1016mm
- Forgings / Flanges: Custom per drawings
- Wire: Φ0.5mm – 12mm
Need certified AISI 321 for high-temperature or aerospace service? Contact Shanghai Hangbo Alloy Group for instant quotations, stock availability and mill certificates — quick response within 10 minutes. Email: sales@hangboalloy.com / Tel: +86 13611656360.
