Sughrue Mion, PLLC
Low alloy steel for geothermal power generation turbine rotor, and low alloy material for geothermal power generation turbine rotor and method for manufacturing the same
A low alloy steel ingot contains from 0.15 to 0.30% of C, from 0.03 to 0.2% of Si, from 0.5 to 2.0% of Mn, from 0.1 to 1.3% of Ni, from 1.5 to 3.5% of Cr, from 0.1 to 1.0% of Mo, and more than 0.15 to 0.35% of V, and optionally Ni, with a balance being Fe and unavoidable impurities. Performing quality heat treatment including a quenching step and a tempering step to the low alloy steel ingot to obtain a material, which has a grain size number of from 3 to 7 and is free from pro-eutectoid ferrite in a metallographic structure thereof, and which has a tensile strength of from 760 to 860 MPa and a fracture appearance transition temperature of not higher than 40° C.
KABUSHIKI KAISHA TOSHIBA THE JAPAN STEEL WORKS,LTD.
C C C C C C
C22C C21D C21D C21D C22C C22C
inventional inventional inventional inventional inventional inventional
Shigeru Makoto Joji Akihiro Osamu Tsukasa Tetsuya Kenichi Koji Satoru Reki Itaru Kazuhiro Kenichi Liang Masayuki
Suzuki Takahashi Kaneko Taniguchi Watanabe Azuma Yamanaka Imai Kajikawa Ohsaki Takaku Murakami Miki Okuno Yan Yamada