20th International Forgemasters Meeting - IFM 2017

In recent years, as part of measures against global warming, utilization of renewable energy has been increasing to reduce CO2 emission. Especially, geothermal power generation, which can supply large scale power steadily, has been being developed around the world, and there is a growing demand for large rotor forgings for large scale geothermal power generation. Japan Casting & Forging Corporation has been manufacturing rotor forgings of geothermal power generation for Fuji Electric, and the diameter of the rotor forgings for geothermal power plants has gotten larger and larger to increase power output and improve thermal efficiency. Therefore, a new steel was desired for such large diameter rotor forgings from the viewpoints of hardenability and cost-effectiveness. Fuji Electric and JCFC have jointly developed a new 2%CrMoV steel for rotor forgings for geothermal power generation, which has good mechanical properties, corrosion resistance and cost-effectiveness. This paper describes the verification results in laboratory testings and the manufacturing results of the actual rotor forging using the new steel.