ASTM A269 TP 347H Seamless Tubes

ASTM A269 TP 347H Seamless Tubes

ASTM A269 TP 347H Seamless Tubes are niobium-stabilized austenitic stainless steel tubes specifically developed for high-temperature service. The higher carbon content in 347H enhances creep strength and improves performance in elevated temperature environments while maintaining excellent resistance to intergranular corrosion.

These seamless tubes are widely used in power generation, petrochemical plants, and heat treatment equipment where superior strength and long-term stability at high temperatures are required.

Specifications

Standard	ASTM A269
Grade	TP 347H
Manufacturing Process	Seamless (Cold Drawn)
Outside Diameter	6 mm to 50.8 mm
Wall Thickness	0.5 mm to 6 mm
Length	Up to 6 Meters / Custom Length
Surface Finish	Annealed & Pickled, Bright Annealed
End Type	Plain End

Key Benefits

• High Creep Strength: Suitable for prolonged exposure to elevated temperatures.
• Niobium Stabilization: Prevents carbide precipitation and intergranular corrosion.
• Excellent Oxidation Resistance: Performs well in high-heat environments.
• Improved Structural Stability: Maintains mechanical properties at high temperatures.
• Reliable Weldability: Good fabrication characteristics for industrial use.

Chemical Composition (Typical)

Element	347H (%)
Carbon	0.04 – 0.10
Chromium	17.0 – 19.0
Nickel	9.0 – 13.0
Niobium (Columbium)	8 x C Min – 1.0 Max
Manganese	2.0 Max

Applications

• Power Generation Boilers
• Heat Exchangers
• Petrochemical Processing Units
• Refineries
• High-Temperature Instrumentation Lines
• Pressure Piping Systems

Quality Testing

• Hydrostatic or Air Underwater Testing
• Ultrasonic Testing (UT)
• Eddy Current Testing
• Tensile & Hardness Testing
• Dimensional & Visual Inspection

Conclusion

ASTM A269 TP 347H Seamless Tubes are engineered for high-temperature and high-pressure applications where strength, oxidation resistance, and corrosion protection are critical. Their stabilized composition and enhanced carbon content make them a reliable solution for demanding industrial environments requiring long-term performance.