ASTM A335 / ASME SA335 P9 / UNS S50400 Cr-Mo Alloy Steel Seamless Pipe

ASTM A335 / ASME SA335 Grade P9 / UNS S50400 Alloy Steel Seamless Pipe Black Painted
 

ASTM A335 P9 is a seamless, chromium-molybdenum alloy steel pipe designed for high-temperature and high-pressure applications. With 8–10% chromium and 0.9–1.1% molybdenum, it offers exceptional resistance to oxidation, creep, and thermal stress at temperatures up to 650°C (1,200°F). It is widely used in critical environments like power plant steam lines, oil refineries, petrochemical processing, and boiler systems where long-term reliability under extreme conditions is essential. P9 requires specialized welding/preheat treatment but outperforms lower-grade alloys in demanding industrial settings.

Equivalent Material ​of ASTM A335/ASME SA335 Alloy Steel Seamless Pipe

Chemical composition(%) of ASTM A335/ASME SA335 Alloy Steel Seamless Pipe

Advantages:

• Superior creep strength under sustained high temps.

• Oxidation/sulfidation resistance (due to Cr content).

• Good weldability (requires pre/post-weld heat treatment).

Mechanical Property of ASTM A335/ASME SA335 Alloy Steel Seamless Pipe

Application

1. Power Plants: Superheaters, reheaters, high-temp steam lines.

2. Oil & Gas: Refinery piping, catalytic cracker units, hydrogen service.

3. Petrochemical: High-pressure/temperature process pipelines.

4. Boilers: Critical pressure parts in fossil-fuel boilers.