ASTM A376 TP347H Seamless Pipes Supplier High-Temperature Austenitic Steel Pipes
1. TP347H Austenitic Stainless Steel Pipes Overview
ASTM A376 TP347H seamless pipes are high-temperature austenitic stainless steel tubes stabilized with niobium (Nb). Engineered for superior creep resistance and oxidation resistance up to 815°C (1,500°F), they withstand extreme thermal cycling and corrosive environments. Compliant with ASTM A376 standards, these pipes are solution-annealed for optimal microstructural stability, making them ideal for critical high-pressure applications.
2. TP347H Chemical Composition
The niobium-stabilized chemistry prevents chromium carbide precipitation, enhancing intergranular corrosion resistance.
| Element | Min (%) | Max (%) |
|---|---|---|
| Carbon (C) | 0.04 | 0.10 |
| Chromium (Cr) | 17.0 | 20.0 |
| Nickel (Ni) | 9.0 | 13.0 |
| Niobium (Nb) | 8×C min | 1.10 |
| Manganese (Mn) | - | 2.00 |
| Silicon (Si) | - | 0.75 |
| Phosphorus (P) | - | 0.045 |
| Sulfur (S) | - | 0.030 |
| Iron (Fe) | Balance | Balance |
3. TP347H Equivalent Grades
Globally recognized cross-standard designations:
| Standard | Equivalent Grade |
|---|---|
| UNS | S34709 |
| EN | 1.4912 |
| DIN | X8CrNiNb16-13 |
| JIS | SUS 347H TB |
| GB | 0Cr18Ni11Nb |
4. TP347H Mechanical Properties
Post-solution annealing properties per ASTM A376:
| Property | Value |
|---|---|
| Tensile Strength | ≥515 MPa (75 ksi) |
| Yield Strength (0.2%) | ≥205 MPa (30 ksi) |
| Elongation (%) | ≥35% (50mm gauge length) |
| Hardness (Max) | 192 HB / 90 HRB |
| Test Temperature | Room Temperature (20°C) |
5. TP347H Dimensional Tolerances
Manufactured to ASTM A376/A999 specifications:
| Parameter | Tolerance |
|---|---|
| Outer Diameter (OD) | ±0.75% for OD ≤ 48.3mm; ±0.50% for OD > 48.3mm |
| Wall Thickness | +20% / -12.5% |
| Length | +6mm / -0mm (for lengths ≤6m) |
| Straightness | 0.0015 × length (mm) |
6. TP347H High-Temperature Applications
Designed for critical thermal and corrosive environments:
- Power Generation: Superheaters, reheaters, and boiler tubes in coal-fired/thermal plants.
- Petrochemical: Catalytic cracker units, furnace manifolds, and reformer tubes.
- Aerospace: Exhaust systems and heat exchangers.
- Nuclear: Steam generator tubing and pressurizer components.
- Industrial Processing: High-temperature fluid transfer systems.
Why Choose Our TP347H Seamless Pipes?
- Precision cold-drawn/hot-finished for uniform wall consistency.
- 100% non-destructive testing (UT/ET) and hydrostatic certification.
- Traceable mill test reports (MTRs) compliant with ASTM A376.
- Custom sizes: OD 6mm–914mm, Wall Thickness 1.24–50mm.
Get in Touch
Have questions about our products or want to discuss a custom order? Our team is ready to help you.