Effect of DC Magnetic Field on Friction and Wear Properties of 45 Steel at Different Velocities

In order to study the effect of Direct Current (DC) magnetic field on friction and wear properties at different velocities, dry sliding friction–wear tests of 45 steel friction coupled with or without magnetic field were conducted at different velocities on a pin–disk tribometer. The test results indicate that the friction coefficient is hardly influenced by magnetic field at various sliding velocities and decreases with the increase in sliding velocity. The magnetic field decreases the wear coefficient of 45 steel dramatically at low sliding velocity; however, it has little effect on wear coefficient at high sliding velocity. The sliding velocity range of oxidation wear of 45 steel is extended by magnetic field. At low sliding velocity, the magnetic field promotes the transition of adhesive wear to oxidative wear of 45 steel. While the sliding velocity is increasing, the ability of magnetic field capturing wear debris is weakening and the influence of magnetic field on tribological behavior and wear mechanism is decreasing. The analysis results of force model for wear debris in non-friction contact area indicate that the quantity of wear debris attracted on the disk is related to the size of wear debris, sliding velocity, magnetic flux density in friction contact area, permeability and remanence of material.