347 Stainless Steel (1.4550) offers superior intergranular corrosion resistance for high-temp & welded assemblies. Ideal for aircraft & chemical processing. Get a quote.
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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347 stainless steel is a niobium (columbium) + tantalum stabilized austenitic grade specifically formulated to prevent sensitization and intergranular corrosion in the 425-815°C (800-1500°F) temperature range. Niobium preferentially forms carbides, preventing chromium carbide precipitation and maintaining corrosion resistance after welding or elevated temperature exposure. This alloy offers excellent high-temperature strength, creep resistance, and oxidation resistance, making it the preferred choice for aircraft exhaust systems, chemical processing equipment, and boiler components requiring long-term reliability at elevated temperatures .
1. Product Specifications & Physical Data
ZYTC Alloy supplies 347 stainless steel in comprehensive mill forms for high-temperature industrial applications requiring verified properties and complete material traceability.
Available Forms: Sheet, plate, bar (flat, hex, round, square), forging stock, tube, and welding wire .
Specifications: ASTM A240, ASTM A276, ASTM A312, EN 10088-2 1.4550, UNS S34700 .
Chemical Composition (Weight %)
347 Stainless Specification
Chromium (Cr)
17.0 - 20.0
Nickel (Ni)
9.0 - 13.0
Niobium + Tantalum (Nb+Ta)
10 × C min - 1.0 max.
Carbon (C)
0.08 max.
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
Thermal Conductivity (RT)
16.2 W/m·K
112 BTU·in/hr·ft²·°F
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; avoid working below 927°C .
Cold Working: Good ductility permits stamping, spinning, deep drawing; work-hardening rate similar to 304 .
Machining: Slightly tougher to machine than 304; requires constant positive feeds, slow speeds, rigid setups, and adequate coolant to manage work hardening .
Welding: Excellent weldability using TIG, MIG, and resistance methods; 347 filler recommended; oxyacetylene not recommended due to carbon pickup .
Material Comparison:
vs. 321 Stainless: Niobium stabilization vs. titanium stabilization; 347 offers superior creep strength above 750°C; 321 offers better oxidation resistance .
vs. 347H: Higher carbon variant (0.04-0.10%) for enhanced high-temperature strength; 347H preferred for creep-limited applications .
vs. 304 Stainless: Stabilization prevents sensitization; essential for applications requiring intergranular corrosion resistance after welding or elevated temperature exposure .
vs. 309/310: Lower chromium and nickel; 347 offers cost-effective high-temperature performance for applications requiring stabilization .
Petrochemical: Elevated temperature process equipment, reformers, cracker tubes
Welded Fabrications: Heavy-section components requiring post-weld high-temperature service without sensitization
Contact ZYTC Alloy for certified 347 stainless steel materials with complete traceability, ASTM/EN specifications, technical datasheets, and competitive pricing on standard sizes or custom-fabricated components.
