304H – High-Carbon 304 Steel: High-Temperature Strength Optimized Alloy

Overview

304H is a high-carbon austenitic stainless steel, optimized for high-temperature applications requiring enhanced creep strength and dimensional stability. With a carbon content of 0.04-0.10%, it delivers superior high-temperature mechanical performance compared to 304 and 304L, enabling continuous service at temperatures up to 650°C and oxidation resistance up to 850°C. It retains the 18.00-20.00% Cr and 8.00-12.00% Ni composition for corrosion resistance, forming a stable austenitic structure that is non-magnetic in the annealed state. This grade has excellent bending and welding properties, making it suitable for high-temperature pressure-bearing components in power and petrochemical industries.

Chemical Composition (wt%)

C: 0.04-0.10, Si ≤ 1.00, Mn ≤ 2.00, P ≤ 0.045, S ≤ 0.030, Cr: 18.00-20.00, Ni: 8.00-12.00, N ≤ 0.10

Typical Mechanical Properties (Annealed Condition)

Tensile Strength (Rm): ≥ 515 MPa; Yield Strength (Rp0.2): ≥ 205 MPa; Elongation (A): ≥ 35%; Brinell Hardness (HB): ≤ 201

Core Advantages

High carbon content enhances high-temperature creep strength and organizational stability; excellent high-temperature oxidation resistance (up to 850°C); good welding and bending performance; non-magnetic; suitable for high-temperature pressure-bearing equipment.

Applications

Large power generator boiler superheater tubes, reheater tubes, steam pipelines, petrochemical heat exchange tubes, and high-temperature industrial furnace components.

Equivalent Grades

UNS S30409, STS304H, SUS304H, EN 1.4307, GB 07Cr19Ni10

Stainless Steel Suppliers

If you have project requirements for stainless steel, we welcome your order. GNEE has a large inventory of popular products for you to choose from. It can be processed into various practical product forms, including plates, coils, tubes, bars, wires, etc. For detailed chemical composition information and free samples, please contact our factory immediately. We offer competitive prices and excellent service.Email: info@gneestainless.com

 

Testing and Documentation: Factory test certificate, EN 10204 3.1, chemical report, mechanical report, destructive testing report, non-destructive testing report, PMI test report, visual inspection report, third-party inspection report, NABL certified laboratory report.
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