3-BODY ABRASIVE WEAR OF 0.98-PERCENT CARBON-STEEL

Low stress abrasion studies of a hypereutectoid steel have been carrie d out using a rubber wheel abrasion test apparatus. Hardness of the st eel was changed by subjecting the specimens to different heat treatmen t cycles. Abrasion tests were conducted at various loads and wheel spe eds using crushed silica sand as the abrasive medium. Wear rates of th e steel in all test conditions decreased significantly during the runn ing-in period prior to attaining steady state values, which was consid ered to be due to the abrasion-induced work hardening of the regions c lose to the abraded surface. Results showed that the increase in bulk hardness of the steel specimen caused a linear increase in wear resist ance. Furthermore, up to a bulk hardness of about 400 HV, the rate of increase was higher than that above 400 HV. Increase in the applied lo ad caused lower wear resistance, while speed did not show any definite trend. One of the material removal mechanisms, in particular, was fou nd to be microcutting as indicated by continuous grooves on the wear s urface and generation of machining chips in the debris. Micropitting w as found to be another wear mechanism as evidenced by the formation of craters on the wear surface and flake-shaped particles in the wear de bris.