sa240 gr 304h temperature range

SA240 GR 304H Temperature Range

SA240 GR 304H (ASME SA 240 Grade 304H, UNS S30409) is a high-carbon austenitic stainless steel optimized for high-temperature service, offering enhanced creep resistance compared to standard 304 or 304L grades. Its temperature range is determined by ASME BPVC Section II, Part D, and industry standards like ASTM A240.

Recommended Temperature Range

• Continuous Service Temperature: Up to 1500°F (815°C). This is the maximum permitted temperature for long-term use in pressure vessels, boilers, and heat exchangers, where the material maintains structural integrity without excessive creep or scaling.
• Intermittent Service Temperature: Up to 1600°F (871°C) for short-term exposure, such as during startup/shutdown or intermittent operation.
• Onset of Scaling: Slight oxidation/scaling begins around 1200°F (649°C), increasing above 1500°F.
• Welding/Heat Treatment Range: Annealing at 1850-2050°F (1010-1120°C), followed by rapid cooling to restore corrosion resistance.

Key Factors Influencing Temperature Range

• Carbon Content (0.04-0.10%): Enhances strength at temperatures above 800°F (427°C), improving creep and rupture resistance vs. 304 (≤0.08% C).
• Limitations: Not suitable for sustained service above 1500°F due to oxidation; for higher temperatures, consider SA 240 GR 321 or 310.
• Comparison:
  • vs. 304/304L: 304H extends range to 1500°F (vs. ~800°F for 304L).
  • vs. 316H: Similar range but 316H better for chlorides.

For detailed specs, refer to ASME BPVC Section II, Part D, Table 1A (allowable stress up to 1500°F: 25.5 ksi at 1000°F).

Gangsteel offers SA240 GR 304H plates at $1.60/kg FOB (MOQ 1 ton). Contact admin@gangsteel.com for quotes.