ASTM A240 304H Stainless Steel Composition & High‑Temperature Strength
ASTM A240 304H (UNS S30409) is the high‑carbon variant of the 304 austenitic stainless steel family. With 18–20% chromium, 8–11% nickel, and a carbon content of 0.04–0.10%, it provides improved creep strength and long‑term stability at elevated temperatures.
304H performs reliably in continuous service between 500–800°C, making it suitable for boiler components, heat exchangers, furnace structures, steam piping, and high‑temperature pressure equipment. It maintains good weldability, though heat input should be controlled to ensure microstructural stability. 304H is supplied as sheets, plates, tubes, bars, and strips. As a heat‑resistant upgrade to 304, it offers superior high‑temperature strength for petrochemical, thermal‑processing, and power‑generation applications.
304H performs reliably in continuous service between 500–800°C, making it suitable for boiler components, heat exchangers, furnace structures, steam piping, and high‑temperature pressure equipment. It maintains good weldability, though heat input should be controlled to ensure microstructural stability. 304H is supplied as sheets, plates, tubes, bars, and strips. As a heat‑resistant upgrade to 304, it offers superior high‑temperature strength for petrochemical, thermal‑processing, and power‑generation applications.