Effect of Heat Treatment Process on Microstructure and Properties of 1Cr15Ni4Mo3N Steel

The effect of heat treatment process on microstructure and mechanical properties of 1Cr15Ni4Mo3N steel was studied by mechanical testing and microstructure observation. The results show that the steel could obtain good machinability which suitable for machine processing by two levels annealing of 780 ℃×5 h air cooling and 590 ℃×4 h air cooling. And fine overall performance would be gained by following heat treatment of quenching at 1 070 ℃×1 h, cold treating at -70 ℃ and tempering at 200-470 ℃.