Product Overview – ASTM A312 TP347H Seamless Pipes
ASTM A312 TP347H is the high carbon version of TP347 stainless steel. The increased carbon content improves high-temperature tensile strength and creep resistance, making it suitable for prolonged service in boilers, superheaters, and refinery piping systems.
Niobium stabilization prevents chromium carbide precipitation during welding and thermal cycling. This ensures resistance to intergranular corrosion even in demanding ASME pressure applications.
Seamless construction provides superior pressure-bearing capability and structural uniformity.
Standard & International Identification - ASTM A312 TP347H Seamless Pipes
ASTM A312 TP347H Seamless Pipe Specifications
| Manufacturing Type : | Seamless |
| Available Sizes: | 1/8″ NB to 24″ NB |
| Schedules: | 5S, 10S, 40S, 80S, 160, XS, XXS |
| Length: | 6m, 12m, Custom Length |
| End Type : | Plain End (PE), Beveled End (BE) |
| Testing : | Hydrostatic, Ultrasonic, PMI Testing |
| Certification : | EN 10204 3.1 / 3.2 MTC |
| Dimensional compliance: | ASME B36.19M. |
All specifications are in accordance of ASTM A312 / ASME SA312 standards. Mechanical and chemical values are as per standard limits. Mill Test Certificates (MTC) available upon request.
Chemical Composition of ASTM A312 TP347H Seamless Pipe
(As per ASTM specification)
| Element | Max (%) |
|---|---|
| Carbon (C) | 0.04 – 0.10% |
| Manganese (Mn) | 2.00 % |
| Silicon (Si) | 1.00 % |
| Phosphorus (P) | 0.045 % |
| Sulfur (S) | 0.030 % |
| Chromium (Cr) | 17.0 – 19.0 % |
| Nickel (Ni) | 9.0 – 13.0% |
| Niobium (Nb + Ta): | 10 × Carbon content (min) |
| Iron (Fe) | Balance |
Note: The higher carbon range differentiates 347H from standard 347.
Mechanical Properties of TP347H Seamless Pipes
| Property | Minimum Value |
|---|---|
| Tensile Strength | ≥ 515 MPa |
| Yield Strength | ≥ 205 MPa |
| Elongation | ≥ 35% |
TP347H offers improved stress rupture strength at elevated temperatures compared to TP347.
High Temperature Performance & Advantages of TP347H Seamless Pipes
SS 347H seamless pipes provide:
For continuous service above 500°C, 347H is often specified over 347.
Applications of ASTM A312 TP347H Seamless Pipes
- 🔸Boiler tubes and components
- 🔸Superheaters and reheaters
- 🔸Oil & gas refinery piping
- 🔸Power plant pressure systems
- 🔸Petrochemical process equipment
- 🔸Heat recovery steam generators (HRSG)
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