查看文章

The aim of the study is to investigate the effect of aging of solution annealed M250 grade maraging steel on the microstructure, room temperature hardness and eddy current (EC) parameters. Specimens of M250 maraging steel were subjected to solution annealing at 1093K for 1h followed by aging at 755K for various durations in the range of 0.25–100h. The hardness was found to increase continuously with aging due to precipitation of intermetallics reaching a maximum and decreased there after due to reversion of martensite to austenite. The aging treatment led to three major microstructural changes, i.e. decrease in dislocation density and quenched-in point defects during initial aging (up to 0.25h), increase in volume fraction of intermetallic precipitates at intermediate duration and a systematic increase in reverted austenite at longer duration (beyond 40h). These microstructural changes alter the electrical …