Deutsche Version: Formstücke aus 10CrMo9-10 (1.7380)
10CrMo9-10 · 2.25Cr-1Mo · EN 10253-2 Type B
The refinery hydroprocessing workhorse. Nelson curve compliance for elevated H₂ partial pressures. Service to 580°C. PWHT mandatory. Widely specified across European refinery and petrochemical projects.
Post-weld heat treatment is mandatory for P22. The higher Mo content compared to P11 increases hardenability and susceptibility to reheat cracking if PWHT is omitted or performed incorrectly. Time-temperature chart and hardness results are included on every EN 10204 3.1 certificate.
P22 (2.25Cr-1Mo) sits on the API 941 Nelson curve at a substantially higher hydrogen partial pressure limit than P11 or carbon steel — making it the default grade for refinery hydrodesulphurisation (HDS), hydrotreating (HDT), and hydrocracking (HCK) reactor effluent piping where elevated temperature and hydrogen partial pressure would cause high-temperature hydrogen attack (HTHA) in lesser grades.
The 1% Mo content provides stronger solid-solution strengthening for creep resistance than P11's 0.5% Mo. P22 is also widely used in conventional and combined-cycle power plants for high-temperature steam piping above 500°C, and in chemical plants for synthesis gas and reformer piping.
| Element | Min | Max | Note |
|---|---|---|---|
| Carbon (C) | 0.08 | 0.14 | Low C for weldability |
| Silicon (Si) | — | 0.50 | — |
| Manganese (Mn) | 0.30 | 0.60 | — |
| Chromium (Cr) | 1.90 | 2.60 | Nelson curve / oxidation |
| Molybdenum (Mo) | 0.87 | 1.13 | Creep resistance |
| Phosphorus (P) | — | 0.025 | — |
| Sulphur (S) | — | 0.010 | — |
| Grade | Cr% | Mo% | Nelson Curve Temp (400 bar H₂) | Max Temp |
|---|---|---|---|---|
| P12 (1.7335) | 1.0 | 0.5 | ~370°C | 550°C |
| P22 (1.7380) | 2.25 | 1.0 | ~440°C | 580°C |
| P5 (1.7362) | 5.0 | 0.5 | ~490°C | 650°C |
| P91 (1.4903) | 9.0 | 1.0 | Not normally applied | 650°C |
Nelson curve temperatures are indicative. Actual HTHA limits depend on hydrogen partial pressure — always consult API 941 Figure 1 for design.
200–250°C minimum. Higher hardenability than P11 due to increased Mo content. Strict preheat control is essential.
ER90S-B3 (GTAW/GMAW) or E9018-B3 (SMAW). Match Cr-Mo filler to base metal — do not substitute with P11 filler.
700–750°C. Hold time per thickness. Cooling rate must be controlled — rapid cooling from PWHT temperature increases risk of reheat cracking.
HAZ hardness ≤248 HBW. Results documented on EN 10204 3.1 certificate.
| EN designation | 10CrMo9-10 |
| Material number | 1.7380 |
| ASTM equivalent | A234 WP22 |
| ASME P-Number | P-No.5A |
| Max temperature | ≤580°C (sustained) |
| Min yield strength | 205 MPa |
| PWHT | 700–750°C (mandatory) |
| Filler (GTAW) | ER90S-B3 |
| Standard | EN 10253-2 Type B |
| Certificate | EN 10204 3.1 standard |
Nelson curve compliance confirmed on certificate. PWHT time-temperature chart included on EN 10204 3.1. 3.2 countersignature available.
Get QuoteDN15–DN600 and larger. Outside diameters follow the EN 10220 / EN ISO 1127 pipe series; wall thickness is matched to your connecting pipe.
| Size | OD (mm) |
|---|---|
| DN 15 | 21.3 |
| DN 20 | 26.9 |
| DN 25 | 33.7 |
| DN 32 | 42.4 |
| DN 40 | 48.3 |
| DN 50 | 60.3 |
| DN 65 | 76.1 |
| DN 80 | 88.9 |
| DN 100 | 114.3 |
| DN 125 | 139.7 |
| DN 150 | 168.3 |
| DN 200 | 219.1 |
| DN 250 | 273.0 |
| DN 300 | 323.9 |
| DN 350 | 355.6 |
| DN 400 | 406.4 |
| DN 450 | 457.0 |
| DN 500 | 508.0 |
| DN 600 | 610.0 |
ASTM A234 WP22 (2.25Cr-1Mo), ASME P-No. 5A.
In refinery hydroprocessing and other hydrogen service, where material selection follows the Nelson curves, and in steam piping up to about 580°C.
PWHT at 700–750°C is mandatory; ER90S-B3 filler is used for GTAW.
Supplying an Indian boiler or ASME B16.9 project? The equivalent grade is listed on our group site ibrfittings.com: ASTM A234 WP22 fittings.
