Steam turbine, rotor shaft thereof, and heat resisting steel
US6224334A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 8, 1997 |
| Grant date | May 1, 2001 |
| Priority date | — |
| Expiry date | Jan 8, 2017 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF05D2300/171
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
A steam turbine comprising a rotor shaft integrating high and low pressure portions provided with blades at the final stage thereof having a length not less than 30 inches, wherein a steam temperature at first stage blades is 530.degree. C., a ratio (L/D) of a length (L) defined between bearings of the rotor shaft to a diameter (D) measured between the terminal ends of final stage blades is 1.4 to 2.3. This rotor shaft is composed of heat resisting steel containing by weight 0.15 to 0.4% C, not more than 0.1% Si, 0.05 to 0.25% Mn, 1.5 to 2.5% Ni, 0.8 to 2.5% Cr, 0.8 to 2.5% Mo and 0.15 to 0.35% V and, further, the heat resisting steel may contain at least one of Nb, Ta, W, Ti, Al, Zr, B, Ca, and rare earth elements.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.