Effect of Tempering Temperature on Microstructure and Wear Resistance of New Wear Resistant Steel

The microstructure transformation characteristics, hardness, impact toughness and wear resistance of a new wear-resistant steel under different tempering conditions (560, 580, 600 and 620 ℃) were comparatively studied with those of H13 steel. The results show that after tempering, the microstructure of the test steel is tempered sorbite; the hardness of the test steel decreases with the increase of the tempering temperature, the maximum tempering hardness is 55.1 HRC at 560 ℃, which is similar to that of H13. On the contrary, the impact energy increases with the tempering temperature increasing, and the maximum impact absorbed energy reaches 335 J at 620 ℃, which is 100 J higher than that of H13. The coefficients of friction of the two steels are close, and the lowest is 0.39-0.41 at 600-620 ℃. Both increment of Cr and decline of Si enhance the precipitation of secondary carbides, ensure the hardness and improve the impact toughness.