Chemical Composition and Mechanical Properties of Seamless Steel Pipe ASTM SA213 T22

Hit：342026-04-02 08:54:49　

Chemical Composition and Mechanical Properties of Seamless Steel Pipe ASTM SA213 T22
Application and Process Key Points
Applicable Temperature: Long-term operating temperature shall not exceed 580–593°C, suitable for superheater and reheater tube bundles in ultra-supercritical/supercritical boilers
Heat treatment process: Normalizing (900–950°C) + Tempering (680–730°C)
Welding Requirements: AWS E9018-B3 electrodes are recommended, with a preheat temperature of 150–200°C, and post-weld hydrogen removal treatment is required
Quality Control: Finished products must pass 100% eddy current flaw detection and ultrasonic inspection to ensure no internal defects

T22 seamless pipe mechanical properties (typical values at room temperature)
Tensile strength σb: ≥ 415 MPa
Yield strength σs: ≥ 205 MPa
Elongation δ5: ≥ 30%
Hardness: ≤ 163 HBW (some standards require ≤207 HB)
After normalizing and tempering treatment, the material exhibits a uniform bainitic microstructure with a grain size typically controlled between grades 5–8, ensuring excellent strength-ductility balance.
Chemical Composition of T22 Seamless Steel Pipe (According to ASTM A213/A213M Standard)
The primary alloying elements of SA213 T22 are chromium (Cr) and molybdenum (Mo), forming a 2.25Cr-1Mo system, with the specific composition range as follows:
Carbon (C): 0.05 – 0.15%
Silicon (Si): ≤ 0.50%
Manganese (Mn): 0.30 – 0.60%
Phosphorus (P): ≤ 0.025%
Sulfur S: ≤ 0.025%
Chromium (Cr): 1.90 – 2.60% (typical value around 2.25%)
Molybdenum (Mo): 0.87 – 1.13% (typical value around 1%)
The component design leverages chromium's oxidation resistance and molybdenum's creep-strengthening effect, enabling the material to maintain superior performance even below 580°C.