A297 HP

Grade HP is a high-temperature austenitic stainless steel casting alloy specified by ASTM A297/A297M, intended for service in extreme thermal environments requiring excellent oxidation resistance and structural stability. It typically contains approximately 25% chromium and 35% nickel, offering superior creep strength and resistance to carburization and scaling. HP is widely used in reformer tubes, furnace coils, and high-temperature process equipment found in petrochemical plants and metallurgical operations. Its high nickel content and stable microstructure make it suitable for prolonged exposure to elevated temperatures and thermal cycling, where durability and dimensional integrity are critical.