In order to investigate the effect of rotational speed on rolling contact fatigue and wear properties of wheel steel under water lubrication,the spalling life,friction coefficient and wear rate of wheel steel samples at different rotational speeds were measured by rollingsliding test.Based on the observation of wear morphology and crack growth morphology,the influence factors of spalling life,friction and wear at different rotational speeds were compared and analyzed.The results show that the oxidation degree of wheel material as well as the friction coefficient are gradually increased with the increase of rotational speed.When the rotational speed is increased from 250 r/min to 500 r/min,the friction coefficient is increased slightly,and the wear rate is decreased due to the increase of strain rate.When the rotational speed is increased from 500 r/min to 1 000 r/min,the wear rate is increased because of the sharp increase of friction coefficient.With the increase of rotational speed,the thickness of plastic flow layer,crack propagation angle,crack branching depth and maximum crack propagation depth show a decreasing trend.The increase of friction coefficient caused by the increase of rotational speed not only shortens the crack initiation life,but also reduces crack branching depth,which leads to the decrease of rolling contact fatigue life with the increase of rotational speeds.