Seamless chrome-moly alloy pipe for the hottest service — refineries, boilers, superheaters and power plants. ASTM A335 grades P1 through P92, supplied with correct pre-heat/PWHT guidance and EN 10204 3.1 / 3.2 certification.
When service temperature and pressure exceed the limits of carbon steel, chrome-molybdenum (Cr-Mo) alloy pipe to ASTM A335 takes over. The added chromium and molybdenum give creep strength and oxidation resistance up to ~600 °C, making these grades the backbone of refinery heaters, boilers, superheaters and thermal power plant.
AAM Steel supplies the full A335 range — from P11 / P22 (1¼–2¼Cr) for general high-temperature lines to the modern P91 / P92 (9Cr) grades for ultra-supercritical power. All are seamless, dimensioned to ASME B36.10M, and supplied with mandatory pre-heat and post-weld heat-treatment (PWHT) guidance.
1¼Cr-½Mo — boilers, superheaters, general high-temp.
2¼Cr-1Mo — power plant, hydrocracker; mandatory PWHT.
5–9Cr-½Mo — refinery & sulphur service.
9Cr-1Mo-V / 9Cr-2W — modern ultra-supercritical power.
| Grade | Cr–Mo | Max °C | Use |
|---|---|---|---|
| P1 | C-½Mo | ~510 | Low-alloy steam/heat lines |
| P2 | ½Cr-½Mo | ~510 | General low-alloy |
| P5 | 5Cr-½Mo | ~600 | Refinery, sulphur service |
| P9 | 9Cr-1Mo | ~600 | High-temp refinery |
| P11 | 1¼Cr-½Mo | ~570 | Boilers, superheaters |
| P12 | 1Cr-½Mo | ~570 | Power/heat exchangers |
| P22 | 2¼Cr-1Mo | ~580 | Power plant, hydrocracker |
| P91 | 9Cr-1Mo-V | ~600 | Modern high-temp power |
| P92 | 9Cr-2W | ~625 | Ultra-supercritical power |
Chrome-moly grade reference. Dimensions per ASME B36.10M — see the carbon steel size chart or use the pipe weight calculator.
Give us the grade (P11/P22/P91…), size, schedule and quantity — we'll quote with PWHT guidance, MTC and delivery terms.