347H stainless steel plate

Q: What is the key difference between 347H and 347 stainless steel plates?

A: The core difference is carbon content: 347H (UNS S34709, EN 1.4550) has a higher carbon range (0.04-0.10%) vs. 347's ≤0.08%. Higher carbon enhances high-temperature strength and creep resistance, making 347H suitable for prolonged service at ≥600°C.

 

Q: What are the critical chemical composition and equivalent grades of 347H?

A: Key components: Cr 17.0-19.0%, Ni 9.0-13.0%, Nb+Ta 8×C-1.0%, C 0.04-0.10%. Equivalents: JIS SUS347H, GB 07Cr18Ni11Nb, ASTM A240 347H, DIN X6CrNiNb18-10 H.

 

Q: What are the mechanical properties and operating temperature range of 347H?

A: Operating temp: -270°C to 950°C. Annealed mechanical properties: Tensile strength ≥515 MPa, Yield strength ≥205 MPa, Elongation ≥40%, Hardness (HB) ≤201.

 

Q: What are the typical industrial applications of 347H stainless steel plate?

A: Designed for high-temperature/high-pressure welded equipment: boiler superheaters/reheaters, nuclear power plant components, chemical reactor vessels, jet engine exhaust systems, and petrochemical cracking units.

 

Q: When should 347H be selected over 347, 321H, or 316H stainless steel plates?

A: Choose 347H for ≥600°C prolonged service requiring superior creep resistance and intergranular corrosion (IGC) resistance. 347 is for lower temp (≤600°C) welded applications; 321H has lower high-temp strength; 316H excels in chloride corrosion but lacks 347H's creep performance.