ASTM A376 TP347H Stainless Steel Pipe
What Is ASTM A376 TP347H Stainless Steel Pipe?
ASTM A376 TP347H stainless steel pipe is a high-temperature resistant austenitic stainless steel pipe manufactured according to ASTM A376 / ASME SA376 standards. These pipes are designed for high-temperature and corrosive service, particularly in applications involving boilers, superheaters, heat exchangers, and refinery piping systems.
Grade 347H stainless steel is a stabilized chromium-nickel alloy containing niobium (Nb), which improves resistance to intergranular corrosion and carbide precipitation during high-temperature operation.
Because of its excellent high-temperature strength and oxidation resistance, ASTM A376 TP347H pipes are widely used in petrochemical plants, power generation systems, oil refineries, and high-temperature industrial pipelines.
ASTM A376 TP347H Pipe Specification
| Item | Specification |
|---|---|
| Standard | ASTM A376 / ASME SA376 |
| Material Grade | TP347H |
| Product Type | Seamless / Welded Pipe |
| Steel Type | Austenitic Stainless Steel |
| Size Range | 1/2″ – 36″ |
| Wall Thickness | SCH 10 – SCH XXS |
| Length | Up to 12 m or as required |
Standard Specification for Seamless Austenitic Steel Pipe for High-Temperature Service
Abstract
This specification covers seamless austenitic steel pipe intended for high-temperature central-station service. The grades covered are five H grades and two nitrogen grades. Pipe may be either hot finished or cold finished, with a suitable finishing treatment. All pipes shall be furnished in the heat-treated condition unless the order specifically states that no final heat treatment shall be applied. Tensile tests, hydrostatic test, nondestructive electric tests, ultrasonic tests, eddy-current tests, tension tests, and flattening tests shall be made to conform to the requirements specified.
ASTM A376 SS 347 Seamless Pipe Chemical Composition
| Grade | C | Ni | Si | N | S | Mn | P | Cr | Mo | |
| SS 347 | min. | 0.04 | 9.00 | – | – | – | – | – | 17.0 | 2.00 |
| max. | 0.10 | 13.00 | 1.00 | – | 0.030 | 2.00 | 0.045 | 20.0 | 3.00 | |
ASTM A376 TP347H Stainless Steel Seamless Pipe Physical Properties
| Properties | Metric | Imperial |
| Density | 7.7 – 8.03 g/cm3 | 0.278 – 0.290 lb/in³ |
ASTM A376 347H Seamless Pipe Mechanical Properties
| Grade | Tensile Strength (MPa) min | Elongation (% in 50mm) min | Yield Strength 0.2% Proof (MPa) min | Hardness | |
| Rockwell B (HR B) max | Brinell (HB) max | ||||
| SS 347 | 515 | 35 | 205 | 92 | 201 |
ASTM A376 Tp347 Equivalent grade
| Grade | UNS No | Old British | Euronorm | Swedish SS | Japanese JIS | ||
| BS | En | No | Name | ||||
| 347 | S34700 | 347S31 | 58G | 1.4550 | X6CrNiNb18-10 | 2338 | SUS 347 |
SA312 TP347H Tensile and SA312 TP347H Stainless pipe Hardness Requirement
|
Stainless Pipe Grade |
SA312 TP347H |
|
UNS Grade |
S34709 |
|
Tensile Strength Mpa |
515 |
|
Yield Strength Mpa |
205 |
|
Elongation % |
35 |
|
Hardness Brinell HBW max |
219 |
|
Hardness Vickers HV max |
230 |
|
Hardness Rockwell HRB max |
95 |
Heat Treatment
ASTM A376 TP347H pipes are typically supplied in solution annealed condition, with heat treatment performed at approximately:
1040°C – 1150°C
followed by rapid cooling.
This process ensures:
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Stable austenitic microstructure
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Maximum corrosion resistance
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Improved high-temperature performance
TP347/TP347H is an austenitic, niobium-stabilized stainless chromium-nickel steel for use at temperatures up to 850°C (1560°F).
Standards
ASTM: TP347, TP347H UNS: S34700, S34709 EN Number: 1.4550, 1.4912 EN Name: X6CrNiNb18-10, X7CrNiNb18-10 W.Nr.: 1.4550 DIN: X 6 CrNiNb 18 10 SS: 2338 AFNOR: (Z6CNNb 18.10) BS: 347S31, 347S51
Applications of ASTM A376 TP347H Pipes
ASTM A376 TP347H stainless steel pipes are widely used in industries requiring high-temperature corrosion resistance.
Power Generation
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Superheater tubes
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Boiler piping systems
Petrochemical Industry
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High-temperature refinery pipelines
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Process equipment piping
Oil Refineries
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Heat exchanger systems
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High-pressure steam pipelines
Chemical Processing
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Corrosion-resistant high-temperature piping systems
ASTM A376 TP347H Stainless Steel Pipe Supplier
We supply high-quality ASTM A376 TP347H stainless steel pipes manufactured in accordance with ASTM and ASME standards.
Our products offer:
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Wide size and thickness range
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Strict quality inspection
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Competitive factory prices
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Export packaging for international delivery
All pipes can be supplied with EN 10204 3.1 Mill Test Certificates.
