1. Specifications & Capability
FUSHUN METAL open-die forges high-pressure and intermediate-pressure (HP / IP) turbine rotor bodies to ASTM A470 Class 8 and the European grade 30CrMoNiV5-11 (1.6946), 1000-1800 mm in diameter and up to 100 t single weight. These are the most highly stressed rotating forgings in a steam turbine, produced from vacuum-degassed ingots on a 20/80 MN fast forging press.
Rotor bodies are supplied with the governing-stage wheel discs forged integrally, eliminating shrink-fit joints and improving high-temperature integrity. Mechanical properties are verified on body samples or separately forged prolonged test pieces.
| Grade | Standard | Typical Use |
|---|---|---|
| ASTM A470 Cl.8 | ASTM A470 | HP/IP rotor bodies, sub-critical and supercritical |
| 30CrMoNiV5-11 / 1.6946 | EN 10250-3 | European HP/IP rotor steel |
2. Components & Service Conditions
These forgings are the single-piece rotor bodies for sub-critical and supercritical steam turbines, serving 300 MW and larger units. The HP/IP rotor carries the hottest, highest-pressure steam – roughly 540-600 C for supercritical machines – together with the full centrifugal load of the blading.
Under sustained high temperature the controlling failure modes are creep rupture and thermal fatigue, so the steel must combine elevated-temperature strength with a low FATT to resist brittle fracture at cold start. Forging a single body with integral discs removes the shrink-fit interfaces that concentrate stress and creep damage, giving the rotor the long service life a utility demands.
3. Grade Equivalents – ASTM A470 Cl.8 / 1.6946
| Designation | Standard | Notes |
|---|---|---|
| ASTM A470 Cl.8 | ASTM A470 | Vacuum-treated Cr-Mo-V rotor steel |
| 30CrMoNiV5-11 / 1.6946 | EN 10250-3 | European Cr-Mo-Ni-V rotor steel |
| 30Cr1Mo1V | GB/T 8732 | Reference only, not used in certification |
| Grade | C | Si | Mn | Cr | Mo | Ni | V |
|---|---|---|---|---|---|---|---|
| 30CrMoNiV5-11 (1.6946) | 0.27-0.34 | 0.40 max | 0.15-0.40 | 1.20-1.50 | 0.55-0.80 | 0.40-0.80 | 0.20-0.30 |
The chromium-molybdenum-vanadium combination provides the creep strength required at HP/IP steam temperatures, while nickel and low impurity control secure the FATT.
4. Manufacturing Process
Steelmaking. FUSHUN METAL melts in an electric arc furnace with ladle refining and vacuum degassing, then casts large ingots up to 114 t. Vacuum treatment lowers hydrogen below the level that causes flaking and controls the trace elements that govern creep ductility.
Forging. The rotor is forged as a single body with integral discs on a 20/80 MN fast forging press, with multiple upsetting and drawing operations to refine the grain and close central porosity.
Heat treatment. Multiple normalizing cycles refine the grain, followed by quenching and tempering to set the strength, toughness and FATT; elevated-temperature creep tests verify long-term rupture strength.
Testing. Full-section UT, MT, mechanical and FATT tests with body sampling where specified, and full traceability from ingot to final machining.
5. Standards & Certification
HP/IP rotors are supplied to ASTM A470 (vacuum-treated carbon and alloy steel forgings for turbine rotors and shafts) and EN 10250-3, with inspection certificates under EN 10204 3.1 and optional 3.2 third-party inspection. FUSHUN METAL holds ISO 9001 and AS9120B certification.
Related forgings: LP rotors and generator rotors.
6. Typical Applications
Supercritical units
HP/IP rotor bodies for supercritical and ultra-supercritical steam turbines.
Sub-critical units
Rotor bodies for 300 MW and larger sub-critical turbines.
Combined-cycle
HP rotors for combined-cycle steam turbine trains.
Refurbishment
Replacement rotors for life-extension programs.
7. Inquiry Essentials
To quote your HP/IP rotor, please provide the rotor drawing, the required strength class, the FATT and creep or stress-rupture requirements, the applicable standard or class, and any body sampling or witness requirements.
