ASTM A312 TP347H Seamless Stainless Steel Pipe | TP347 Pipe Mabufacturer
ASTM A312 TP347H seamless stainless steel pipes and ASTM A312 TP347 stainless steel pipes are niobium-stabilized austenitic stainless steel pipes designed for high-temperature, high-pressure and corrosive service applications.
Manufactured according to ASTM A312, these stainless steel pipes provide excellent resistance to intergranular corrosion, oxidation and creep deformation, making them suitable for long-term elevated-temperature service environments.
TP347 and TP347H stainless steel pipes are widely used in:
- oil refineries
- petrochemical plants
- power generation facilities
- heat exchangers and boilers
- high-temperature process piping systems
We are a professional supplier and exporter of ASTM A312 TP347H seamless stainless steel pipe, SA312 TP347H pipe and ASTM A312 TP347 stainless steel pipe.
What is ASTM A312?
ASTM A312 is the standard specification covering:
- seamless stainless steel pipe
- welded stainless steel pipe
- heavily cold-worked austenitic stainless steel pipe
These pipes are intended for:
- high-temperature service
- corrosive service
- pressure piping applications
ASTM A312 specifies requirements for:
- chemical composition
- mechanical properties
- heat treatment
- dimensional tolerances
- testing and inspection procedures
ASTM A312 TP347 and TP347H Stainless Steel Grades
ASTM A312 TP347
TP347 is a niobium-stabilized austenitic stainless steel that helps prevent chromium carbide precipitation during welding and elevated-temperature exposure.
Main characteristics:
- excellent corrosion resistance
- good weldability
- oxidation resistance
- resistance to intergranular corrosion
- suitable for elevated-temperature service
ASTM A312 TP347H
TP347H is the high-carbon version of TP347 stainless steel developed to improve:
- creep strength
- elevated-temperature performance
- long-term thermal stability
TP347H stainless steel pipes are commonly used in:
- boilers
- heat exchangers
- petrochemical processing equipment
- exhaust systems
- high-temperature chemical processing plants
By adding niobium (Nb) as a stabilizing element, TP347H improves resistance to carbide precipitation and structural instability during high-temperature operation.
TP347H performs particularly well in sustained operating temperatures between:
- 800°F – 1500°F (427°C – 816°C)
TP347H is also suitable for heavy welded components that cannot be re-annealed after welding.
ASTM A312 TP347 vs TP347H
| Property | TP347 | TP347H |
|---|---|---|
| UNS Number | S34700 | S34709 |
| Carbon Content | Lower Carbon | Higher Carbon |
| Main Feature | Corrosion Resistance | Better Creep Strength |
| High Temperature Performance | Good | Excellent |
| Typical Applications | General Corrosive Service | High-Temperature Service |
TP347H is commonly selected for sustained elevated-temperature applications requiring improved creep resistance.
ASTM A312 TP347 / TP347H Pipe Specifications
| Specification | Details |
|---|---|
| Standard | ASTM A312 / ASME SA312 |
| Grades | TP347 / TP347H |
| Manufacturing Types | Seamless / Welded / Cold Worked |
| Material Type | Austenitic Stainless Steel |
| Dimensions Standard | ASME B36.19M / ASME B36.10M |
| Outer Diameter | 10.3 – 762 mm |
| Wall Thickness | 1 – 50 mm |
| Length | Random Length / Fixed Length |
| Delivery Condition | Solution Annealed |
| Surface Finish | Pickled / Passivated |
Equivalent Material Standards
| Country | Standard | Grade |
|---|---|---|
| USA | ASTM | TP347 / TP347H |
| UNS | UNS | S34700 / S34709 |
| EN / DIN | DIN | 1.4550 |
| Japan | JIS | SUS347 / SUS347HTB |
| Korea | KS | STS347 / STS347H |
| China | GB | 06Cr18Ni11Nb / 07Cr18Ni11Nb |
Chemical Composition of ASTM A312 TP347H
| Element | Composition (%) |
|---|---|
| Carbon (C) | 0.04 – 0.10 |
| Manganese (Mn) | ≤ 2.00 |
| Phosphorus (P) | ≤ 0.045 |
| Sulfur (S) | ≤ 0.030 |
| Silicon (Si) | ≤ 1.00 |
| Chromium (Cr) | 17.0 – 19.0 |
| Nickel (Ni) | 9.0 – 13.0 |
| Niobium + Tantalum (Nb + Ta) | 8 × C min – 1.00 max |
The niobium stabilizing element improves resistance to intergranular corrosion and carbide precipitation.
Mechanical Properties of ASTM A312 TP347H
| Property | Requirement |
|---|---|
| Tensile Strength | ≥ 515 MPa |
| Yield Strength | ≥ 205 MPa |
| Elongation | ≥ 35% |
| Hardness | ≤ 192 HBW / ≤ 90 HRB |
These mechanical properties provide reliable performance under elevated-temperature and pressure conditions.
Heat Treatment Requirements
ASTM A312 TP347H stainless steel pipes are normally supplied in solution annealed condition.
| Grade | Heat Treatment |
|---|---|
| TP347H | Solution Annealing |
Solution Annealing Temperature
- 1900°F (1040°C) Minimum
Cooling Method
- Water quenching
- Rapid cooling
Proper heat treatment improves:
- corrosion resistance
- weldability
- microstructural stability
- toughness
ASTM A312 vs ASME SA312
ASTM A312 and ASME SA312 are technically equivalent specifications for austenitic stainless steel pipes.
SA312 TP347H pipes are commonly specified in:
- boiler systems
- pressure vessels
- ASME code piping projects
The ASME designation is generally used for pressure equipment and boiler applications.
Testing and Inspection
To ensure compliance with ASTM A312 requirements, TP347H stainless steel pipes can be supplied with:
- flattening test
- flaring test
- hardness test
- hydrostatic test
- eddy current testing (ET)
- ultrasonic testing (UT)
Optional inspections include:
- PMI testing
- spectro chemical analysis
- mechanical properties testing
- radiographic testing
- straightness testing
- roughness testing
- intergranular corrosion testing
- impact testing
- grain size determination
Surface Finish
ASTM A312 TP347H pipes can be supplied with:
- pickled finish
- passivated finish
- annealed and pickled finish
- polished finish
- bright annealed finish
Surface condition can be customized according to project requirements.
Applications of ASTM A312 TP347H Stainless Steel Pipe
ASTM A312 TP347H seamless stainless steel pipes are widely used in:
- refinery heater tubes
- boiler superheater systems
- reheater piping
- heat exchanger piping
- high-temperature chemical processing
- thermal equipment
- petrochemical process piping
- exhaust systems
Their excellent oxidation resistance and creep strength make them suitable for long-term elevated-temperature service.
Why Choose Our ASTM A312 TP347H Pipe?
We provide:
- full material traceability
- strict quality inspection
- PMI testing
- custom dimensions
- fast delivery
- third-party inspection support
- worldwide export service
Our ASTM A312 TP347H seamless stainless steel pipes are manufactured according to international standards for reliable high-temperature industrial performance.
ASTM A312 TP347 Stainless Steel Seamless Pipe
ASTM A312 TP347 and TP347H stainless steel pipes offer outstanding resistance to intergranular corrosion, oxidation, and creep deformation, making them ideal for demanding high-temperature and high-pressure industrial applications.
Fully compliant with ASTM A312, TP347 / TP347H pipes are widely used in refineries, petrochemical plants, power generation facilities, and high-temperature piping systems where reliability and long service life are critical.
With excellent weldability, strong high-temperature strength, and superior corrosion resistance, TP347H stainless steel pipes are a proven solution for critical industrial environments.
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ASTM A213 TP347H Boiler Tubes
