13Ni-15Co-10Mo系マルエージ鋼 (400ksi級) の析出過程
1977 年 63 巻 3 号 p. 505-512
詳細
1977 年 63 巻 3 号 p. 505-512
A resistometric investigation of the precipitation process in 13Ni-15Co-10Mo 400ksi-grade maraging steels has been made in comparing with the precipitation in 18Ni-10Co-5Mo, 14Ni-15Co-5Mo, and 14Ni-15Co-7Mo maraging steels. Two precipitation stages are observed in aging of the 400ksi-grade maraging steels. The precipitation stages in the lower and higher temperature regions are named as stage-PA and stage-PB, respectively. In the precipitation of the 18Ni-10Co-5Mo, 14Ni-15Co-5Mo, and 14Ni-15Co-7Mo maraging steels, two stages are also observed.
In the 18Ni-10Co-5Mo, 14Ni-15Co-5Mo, and 14Ni-15Co-7Mo maraging steels, most of the precipitateds formed in the low temperature percipitation stage are resoluted by heating to temperatures where the high temperature precipitation stage preceeds rapidly. However, the reversion of the precipitates formed in the stage-PA of 400ksi-grade maraging steel is relatively small in heating up to 600°C. Accordingly, it is considered that the upper limit of temperatures where the stage-PA proceeds as the early precipitation stage of the 400ksi-grade maraging steel is located at a relatively high temperature. The strength of the 400ksi-grade maraging steel is reached to its maximum near the end of the stage-PA, and is decreased gradually with the proceeding of the stage-PB.
