先進型 12Cr 鋼ロータ材の 593℃-700MW 蒸気タービンプラントへの実用化

概要

論文の詳細を見る
The largest class IP rotor forging with 1200mm in maximum diameter, for steam turbine of 700MW class to be operated at 538/593℃ steam temperature, has successfully been manufactured with an advanced 12Cr rotor material which we call this alloy TMK1, through the electroslag remelting (ESR) process from 55t ingot. The quality and material characteristics of this advanced 12Cr rotor forging were evaluated for various locations of this rotor. In spite of a large ingot, neither chemical composition changes nor mechanical properties differences with positions in the rotor could be recognized. This is due to the ESR process and the advantages of the ESR are fully exhibited. Significant improvements in toughness and creep rupture properties were recognized in this rotor forging. Especially, the improvement of creep rupture strength in this advanced 12Cr steel is mainly attributed to dispersion strengthening by V_4C_3 and NbC in addition to solid-solution strengthening by Mo. It was confirmed that this rotor had sufficient characteristics for a large 12Cr steel rotor for 593℃ steam temperature.
社団法人日本鉄鋼協会の論文
1992-06-01