開発 Ni-Co 基鍛造超合金を用いた模擬タービンディスクの機械的特性

New kinds of cast and wrought (C & W) Ni-Co base superalloys (TMW alloys) have been developed based on the innovative concept of combining two kinds of γ-γ′ two-phase alloys, Ni-base and Co-base alloys, for the applications of turbine disks and high-pressure compressor blades. The results based on testing 20 kg ingots indicate that TMW alloys show excellent high temperature strength and formability, may provide 50°C temperature advantage in 630 MPa/100 h creep performance over C & W alloy U720Li. In this paper, we report our new results on the full-scale pancakes manufactured through the C & W process for real components. The results indicate that TMW alloys had good process-ability in the ingot making and forging into disk pancakes. Pancake disks with fine grain size of about 10 μm were successfully obtained for TMW alloys. TMW alloys provide 58°C to 76°C temperature advantages in 0.2% creep strain life under the 630 MPa condition, over alloy U720Li.