347H Stainless Steel - Superior creep strength above 1000°F with excellent intergranular corrosion resistance. Ideal for refinery and chemical processing applications. Request pricing.
Delivery :
FOB
minimum order :
50 kilograms
Supply Ability :
5000kilograms / Month
Stock Time :
7-10Day
Country of Origin :
CHINA
Quantity :
add to cart
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347H is the high-carbon variant of niobium-stabilized 347 stainless steel, specifically formulated for enhanced creep resistance and stress-rupture strength at temperatures exceeding 537°C (1000°F). With controlled carbon content (0.04-0.10%) and niobium stabilization (min. 8× carbon), it offers superior high-temperature mechanical properties while maintaining excellent resistance to sensitization and intergranular corrosion. This grade is the preferred choice for petroleum refining, chemical processing, and power generation equipment requiring long-term structural integrity at elevated temperatures .
1. Product Specifications & Physical Data
ZYTC Alloy supplies 347H stainless steel in comprehensive mill forms for high-temperature industrial applications requiring verified creep properties and complete material traceability.
Available Forms: Sheet, plate, pipe, tube, bar, and fittings .
Specifications: ASTM A240, ASTM A276, ASTM A312, EN 10088-2 1.4961, UNS S34709 .
Chemical Composition (Weight %)
347H Stainless Specification
Chromium (Cr)
17.0 - 20.0
Nickel (Ni)
9.0 - 13.0
Niobium + Tantalum (Nb+Ta)
8 × C min - 1.0 max.
Carbon (C)
0.04 - 0.10
Manganese (Mn)
2.0 max.
Silicon (Si)
1.0 max.
Phosphorus (P)
0.040 max.
Sulfur (S)
0.030 max.
Iron (Fe)
Balance
Physical Properties
Metric
Imperial
Density
7.9 - 8.0 g/cm³
0.285 - 0.289 lb/in³
Melting Point
1400 - 1425°C
2550 - 2600°F
Modulus of Elasticity
190 - 210 GPa
27.6 - 30.5 × 10⁶ psi
Poisson's Ratio
0.27 - 0.30
0.27 - 0.30
Mechanical Properties
Value
Unit
Tensile Strength (min.)
515 MPa
75 ksi
Yield Strength (min.)
205 MPa
30 ksi
Elongation (min.)
30%
30%
Hardness (Brinell)
187 max.
187 max.
Rupture Strength (750°C/100,000h)
38-39 MPa
5.5-5.7 ksi
2. Fabrication & Material Comparison
Heat Treatment: Solution anneal 1010-1193°C (1850-2180°F), rapid water quench; cannot be hardened by heat treatment .
Hot Working: Forge at 1149-1232°C (2100-2250°F); reheat as necessary .
Cold Working: Good ductility permits forming operations; work-hardening rate similar to standard 347 .
Machining: Similar to standard 347; requires constant positive feeds, slow speeds, rigid setups, and adequate coolant .
Welding: Excellent weldability using TIG, MIG, and resistance methods; 347 filler recommended; no post-weld heat treatment required for corrosion resistance .
Material Comparison:
vs. 347 Stainless: Higher carbon provides superior creep strength above 537°C; identical niobium stabilization ensures sensitization resistance .
vs. 321H: Niobium-stabilized vs. titanium-stabilized; 347H offers higher creep strength; 321H offers better oxidation resistance .
vs. 316H: Stabilization prevents sensitization without molybdenum; 347H preferred for applications requiring intergranular corrosion resistance after elevated temperature exposure .
vs. 309/310: Lower chromium and nickel; 347H offers cost-effective high-temperature performance for applications requiring stabilization .
Contact ZYTC Alloy for certified 347H stainless steel materials with complete traceability, ASTM specifications, technical datasheets, and competitive pricing on standard sizes or custom-fabricated components.
