Effect of Tempering Temperature on Microstructure and Properties of 5Cr5MoSiV1 Steel

The spheroidized annealed 5Cr5MoSiV1 steel was quenched at 1 050 ℃ for 1 h and tempered at different temperatures (515,530,560,590,620 ℃) for 1 h. The effect of tempering temperature on the microstructure, hardness, impact toughness, and wear resistance of the steel was studied. The result show that the microstructure of tempered 5Cr5MoSiV1 steel at different temperatures consisted of tempered sorbite and a small amount of carbides. With the increase of tempering temperature, the carbide increased in number and aggregated and grew. When the tempering temperature exceeded 560 ℃, the recovery and recrystallization of the matrix increased, and the characteristics of martensite strip gradually became blurred. With the increase of tempering temperature, the hardness of 5Cr5MoSiV1 steel decreased, the impact absorption energy first remained basically unchanged and then increased, and the wear mass loss first decreased fluctuatingly and then increased. The suitable tempering temperature for 5Cr5MoSiV1 steel was 590 ℃, and the steel had good impact toughness and wear resistance with a hardness of 51.1 HRC, an impact absorption energy of 25.7 J, and a wear mass loss of 3.864 g.