Abstract: The effect of quenching and tempering times on the microstructure and friction and wear behavior of C110 seamless steel pipe was studied. The results show that with the increased of quenching and tempering times, the grain size of C110 steel was refined, but the refinement effect was becoming less and less obvious, and the second phase in the material continued to aggregate and grow. Under the joint influence of grain size and second phase, the hardness of C110 steel showed a trend of first increasing and then decreasing with the increased of quenching and tempering times. After secondary quenching and tempering treatment, the grain refinement and fine grain strengthening effect of C110 steel were significant, while the growth of the second phase was not significant, indicated the best wear resistance of the material.