what is sa240 304h stainless steel?

What is SA240 304H Stainless Steel?

At Gangsteel, a leading manufacturer and exporter of stainless steel products, we supply premium SA240 304H stainless steel plates compliant with ASME SA 240 and ASTM A240 standards. SA240 304H, also known as AISI 304H, UNS S30409, or 1.4948, is a high-carbon variant of the austenitic stainless steel 304, optimized for enhanced high-temperature strength and creep resistance.

This versatile material is ideal for applications like boilers, heat exchangers, and SA240 304H pipe, where durability at elevated temperatures (up to 815°C/1500°F) is critical. This guide details the properties, specifications, and uses of SA240 304H stainless steel. For inquiries, contact us at admin@gangsteel.com or explore our ASME SA 240 stainless steel plate offerings.

Overview of SA240 304H Stainless Steel

SA240 304His specified under ASME SA 240 for chromium and chromium-nickel stainless steel plates, sheets, and strips used in pressure vessels and high-temperature service. As a high-carbon (0.04-0.10%) version of 304, SA240 304H provides improved creep and stress rupture properties compared to SA 240 GR 304 (≤0.08% carbon) or SA 240 GR 304L (≤0.03% carbon). It retains the austenitic structure, offering non-magnetic properties in the annealed state (SA 240 304 non magnetic) and a density of 8.00 g/cm³. SA240 304H is commonly used in power generation, petrochemical, and chemical industries.

Chemical Composition of SA240 304H

The chemical composition of SA240 304H stainless steel ensures high-temperature performance and corrosion resistance:

• Carbon: Higher (0.04-0.10%) than 304 (≤0.08%) or 304L (≤0.03%), boosting creep resistance but potentially increasing sensitization risk during welding.
• Chromium: Forms a passive oxide layer for corrosion protection.
• Nickel: Maintains austenitic structure and non-magnetic properties.

For equivalents, SA240 304H aligns with EN 1.4948 and JIS SUS304H.

Mechanical Properties of SA240 304H

The mechanical properties of SA240 304H stainless steel for annealed plates (8-75 mm thick) support high-temperature structural use:

• High-Temperature Strength: SA240 304H excels with higher creep resistance than 304/304L, with allowable stress of 25.5 ksi at 1000°F vs. 18.6 ksi for 304.
• Comparison: Similar to 304 but superior to 304L (485 MPa tensile, 170 MPa yield) at elevated temperatures.

Physical Properties

• Density: 8.00 g/cm³, ideal for lightweight designs (e.g., a 1m x 1m x 3mm plate weighs ~24 kg).
• Melting Point: ~1400-1450°C, suitable for high-temperature processing.
• Thermal Conductivity: 16.2 W/m·K, moderate for heat transfer.
• Coefficient of Thermal Expansion: 17.2 × 10⁻⁶/K (20-100°C), stable across temperatures.
• Electrical Resistivity: 0.72 × 10⁻⁶ Ω·m, good for non-conductive applications.

Corrosion Resistance

SA240 304Hstainless steel provides corrosion resistance similar to 304:

• Excellent in atmospheric conditions, freshwater, and mild acids (food-grade).
• Outperforms SS204 vs SS 304 due to higher nickel content.
• Less resistant to chloride pitting than SA 240 GR 316L (molybdenum-enhanced). For chloride environments, explore sa 240 gr 316l.

Higher carbon increases sensitization risk during welding, potentially reducing weld zone corrosion resistance unless annealed.

Weldability

• Weldability: Fair, using ER308H or ER308 fillers. The higher carbon (0.04-0.10%) raises sensitization risk, requiring controlled heat input (<2.0 kJ/mm) or post-weld annealing.
• Comparison: SA 240 GR 304L (≤0.03% carbon) is better for welds; SA 240 GR 321 (titanium-stabilized) for high-temperature welds. See sa 240 gr 304l.

Applications of SA240 304H

SA240 304Hstainless steel is used in:

• Boilers and Pressure Vessels: High-temperature strength for steam drums and headers.
• Heat Exchangers: Creep resistance for elevated temperatures.
• Chemical Industry: Vessels and SA 240 GR 304 pipe for mild corrosives at high temperatures.
• Power Generation: Superheaters, reheaters, and components up to 815°C.
• Piping and Fittings: SA240 304H pipe, flanges, and fittings for high-temperature systems.

For milder environments, consider sa 240 gr 304 or sa 240 gr 304l.

Pricing and Availability at Gangsteel

As of October 18, 2025, SA240 304H stainless steel plate prices (2B finish, 3-6mm thick) range from $1.60-$3.50/kg globally, slightly higher than SA 240 GR 304 ($1.55-$3.50/kg) due to specialized applications. Gangsteel offers competitive pricing at $1.60/kg FOB (MOQ 1 ton) for standard sizes (e.g., 4’x8’, 5’x10’) and custom cuts like plate 2 mm SUS 304, with finishes like 2B, No.1, and polished. Our SS 304 plate price is 5-10% below market averages. Contact admin@gangsteel.com for quotes.

Why Choose Gangsteel?

Gangsteel offers certified SA240 304H stainless steel with consistent properties and competitive SA240 304H stainless steel plate price. Our 600+ ton inventory supports global delivery for applications from high-temperature pressure vessels to heavy plates. For more details on SA240 304H stainless steel, visit our sa 240 gr 304h page or email admin@gangsteel.com.