TP347H Stainless Steel Seamless Pipe DN10-DN400 ASTM EN

Key Parameters

• Alloy Grade: TP347H (a niobium-stabilized austenitic stainless steel, with "H" indicating a higher carbon content for improved high-temperature strength).
• Chemical Composition (Typical, %):
  • Chromium (Cr): 17.0 - 19.0 (boosts oxidation and corrosion resistance).
  • Nickel (Ni): 9.0 - 13.0 (stabilizes the austenitic structure, enhancing ductility and toughness).
  • Niobium (Nb) + Tantalum (Ta): 10×C - 1.00 (stabilizes carbides, preventing intergranular corrosion during welding or high-temperature service).
  • Carbon (C): 0.04 - 0.10 (higher carbon content compared to standard 347, improving creep strength at elevated temperatures).
  • Manganese (Mn): ≤ 2.0.
  • Silicon (Si): ≤ 0.75.
  • Phosphorus (P): ≤ 0.040.
  • Sulfur (S): ≤ 0.030.
• Mechanical Properties:
  • Tensile Strength: ≥ 550 MPa.
  • Yield Strength: ≥ 205 MPa.
  • Elongation: ≥ 35% (in 50mm gauge length).
  • High-Temperature Performance: Maintains stability at continuous service temperatures up to 900°C, with excellent resistance to creep (slow deformation under constant load) and oxidation.

Standards

• ASTM A312/A312M (Standard Specification for Seamless and Welded Austenitic Stainless Steel Pipes).
• ASTM A213/A213M (Standard Specification for Seamless Ferritic and Austenitic Alloy-Steel Boiler, Superheater, and Heat-Exchanger Tubes).
• ASME SA312/SA213 (Codes for pressure vessel and boiler applications, widely adopted in energy and petrochemical industries).
• EN 10216-5 (European standard for seamless steel tubes for pressure purposes, applicable to austenitic stainless steels).

Specifications

• Form: Seamless tube (no welds, ensuring uniform strength and leak resistance, critical for high-pressure systems).
• Processing: Hot-rolled (enhances grain structure, improving mechanical strength and suitability for high-temperature service).
• Nominal Diameter (DN): DN10 to DN200 (equivalent to outer diameters approximately 17.2mm to 219.1mm, covering a range of industrial piping needs).
• Wall Thickness: Typically 1.2mm to 12mm (customizable based on pressure and application requirements, with precise tolerances for seamless fit).
• Length: Common lengths include 6m, 12m, or cut-to-size as per customer specifications.

Similar Grades

• TP321H: Titanium-stabilized instead of niobium, offering similar high-temperature performance but with slightly lower creep strength than 347H.
• TP347: Lower carbon variant (C ≤ 0.08%) of 347H, suitable for moderate-temperature applications where high creep resistance is not required.
• 1.4550 (EN designation): European equivalent to TP347H, with matching chemical composition and mechanical properties.
• TP316H: Molybdenum-containing (2-3% Mo) for enhanced corrosion resistance in chloride environments, with high-temperature strength comparable to 347H.

Applications

• Power Generation: Boiler tubes, superheaters, and reheaters in fossil fuel and nuclear power plants, where resistance to high heat and steam oxidation is critical.
• Petrochemical Industry: Piping and heat exchangers in refineries and chemical plants, handling high-temperature hydrocarbons and corrosive process fluids.
• Aerospace and Aviation: Exhaust systems and high-temperature ducting in aircraft engines, where structural stability under extreme heat is essential.
• Oil and Gas: Downhole tubing and surface piping in high-temperature wells, resisting corrosion from aggressive reservoir fluids.
• Industrial Furnaces: Piping for furnace components, radiant tubes, and heat recovery systems exposed to continuous high temperatures.