Effect of Carbon Content on the Dry Friction and Wear of Carbon Steel under Magnetic Field and the Mechanism

To study the sliding dry friction behavior and wear properties of low carbon steel, medium carbon steel and high carbon steel based on a self-made HY-100 pin-disc friction and wear tester with and without magnetic field. The frictional surface and sub-surface were analyzed by scanning electron microscope and metallographic microscope, and the influence of carbon content on mechanism under magnetic field condition was explored. The results show that the friction coefficient of carbon steels with different carbon content varied with and without magnetic field. The friction coefficient of low carbon steels decreased and the medium and high carbon steels increased under the external magnetic field. The influence of magnetic field on the friction coefficient became not obvious with the increase of carbon content, and the tribo-oxidation decreased. This suggested the influence of magnetic control dry friction and wear characteristics of carbon steel was weakened. The external magnetic field effectively improved the wear performance of carbon steels. With the increase of carbon content, the effect of magnetic field on the wear rate was greate, which was due to the competitive oxidation of carbon and iron. The competitive oxidation of carbon and iron not only enabled the wear reduction effect of iron oxides but also slowed down the spalling of accumulated iron oxides. The EDS results indicated that high carbon steel had the lowest oxygen to iron ratio, which was in good agreement with the iron and carbon competitive oxidation model.