sa 240 304h material properties

SA 240 304H Material Properties

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

This article details the material properties of SA 240 304H, including chemical composition, mechanical properties, physical properties, corrosion resistance, weldability, and applications for uses like boilers, heat exchangers, and SA 240 GR 304 pipe. For inquiries, contact us at admin@gangsteel.com or explore our ASME SA 240 stainless steel plate offerings.

Overview of SA 240 304H Material Properties

SA 240 304H is specified under ASME SA-240/SA-240M for chromium and chromium-nickel stainless steel plates, sheets, and strips used in pressure vessels, boilers, and high-temperature corrosive service. The high carbon content (0.04-0.10%) distinguishes it from SA 240 GR 304 (≤0.08% carbon) and SA 240 GR 304L (≤0.03% carbon), providing improved strength at elevated temperatures (up to ~815°C/1500°F). SA 240 304H 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. Gangsteel’s sa 240 gr 304h plates meet these standards.

Chemical Composition

The chemical composition of SA 240 304H enhances its high-temperature performance:

• Carbon: Higher content (0.04-0.10%) increases creep resistance and strength at elevated temperatures compared to SA 240 GR 304.
• Chromium: Forms a passive oxide layer for corrosion resistance in mild environments.
• Nickel: Ensures austenitic structure and non-magnetic properties.
• Comparison: Lacks molybdenum (unlike SA 240 GR 316L) and titanium (unlike SA 240 GR 321), limiting chloride resistance but optimizing high-temperature strength.

For detailed specifications, refer to our SS 304 data sheet for comparison with SA 240 GR 304.

Mechanical Properties

The mechanical properties of SA 240 304H for annealed plates (8-75 mm thick) support high-temperature applications:

• Strength: Comparable to SA 240 GR 304 (515 MPa tensile, 205 MPa yield) but stronger than SA 240 GR 304L (485 MPa tensile, 170 MPa yield). Higher carbon enhances creep strength at elevated temperatures (e.g., allowable stress of 25.5 ksi at 1000°F vs. 18.6 ksi for 304).
• Ductility: High elongation (≥40%) supports forming for applications like plat stainless 304 or plate 2 mm SUS 304.
• Cold-Working: Can increase tensile strength (up to 900 MPa) but reduces ductility.

Physical Properties

• Density: 8.00 g/cm³, identical to SA 240 GR 304, 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.
• Maximum Service Temperature: ~815°C (1500°F) for continuous service, higher than 304/304L due to enhanced creep resistance.

Corrosion Resistance

SA 240 304H offers corrosion resistance similar to SA 240 GR 304:

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

The higher carbon content may increase sensitization risk during welding, potentially reducing corrosion resistance in weld zones unless annealed.

Weldability

• Weldability: Fair, using ER308 or ER308H fillers. The higher carbon content (0.04-0.10%) increases the risk of sensitization (chromium carbide precipitation), requiring controlled heat input (<2.0 kJ/mm) or post-weld annealing to maintain corrosion resistance.
• Comparison: SA 240 GR 304L (≤0.03% carbon) is preferred for critical welds due to lower sensitization risk. For high-temperature welds, SA 240 GR 321 (titanium-stabilized) is an alternative. See sa 240 gr 321.

Applications

SA 240 304H material is used in:

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

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

Pricing and Availability at Gangsteel

As of October 18, 2025, SA 240 304H 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 starting 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, and dual-certified SA 240 TP 304/304L plates are available for flexibility. For pricing details, contact admin@gangsteel.com.

Why Choose Gangsteel?

Gangsteel provides certified SA 240 304H plates with consistent material properties and competitive SA 240 304 plate price. Our 600+ ton inventory supports global delivery for applications from high-temperature pressure vessels to heavy plates.

For quotes or to learn more about SA 240 304H material properties, visit our sa 240 gr 304h page or email admin@gangsteel.com.