Abstract: Effect of tempering parameters on microstructure of the G95Cr18 steel was investigated by means of OM, SEM and XRD. In addition, the effects of different tempering temperatures and times on hardness, tensile properties and impact property were studied by using Vickers hardness tester, electronic universal testing machine and drop hammer impact testing machine. The results show that the retained austenite content of the G95Cr18 steel decreases gradually with the increase of tempering temperature. When the tempering temperature is 200 ℃, the decomposition amount of retained austenite is less than 3.6%, which is caused by the increase of thermal stability due to the carbon partitioning effect. When the tempering temperature is higher than 400 ℃, the retained austenite content can meet the requirement of＜6%.The hardness of the G95Cr18 steel first decreases and then increases with the increase of tempering temperature, and the secondary hardening temperature is 400 ℃. With the tempering temperature increasing, the impact absorbed energy of the G95Cr18 steel increases first and then decreases. When the tempering temperature is 300 ℃, the impact absorbed energy reaches the maximum, which is 7.1 J. When the tempering temperature is lower than 300 ℃, increasing tempering times has little effect on the microstructure and strength and toughness of the G95Cr18 steel. When the tempering temperature reaches 500 ℃, the comprehensive properties of the G95Cr18 steel decreases with tempering times increasing.

Key words: G95Cr18 stainless steel, tempering, retained austenite, microstructure, mechanical properties