Effect Of Nonuniform Microstructure On Wear Property Of Er8 Wheel Steel

Because nonuniform microstructures may accelerate the wear rate of wheels made from ER8 steel, a wear test was performed on a wheel sample with a nonuniform microstructure, and the wear properties were compared with that of a wheel composed of a uniform microstructure. In addition, the wear mechanism of the wheel with a nonuniform microstructure was analyzed. In addition to the uniform microstructure of pearlite and proeutectoid ferrite, upper bainite was observed in the wheel with a nonuniform microstructure. The upper bainite disrupted the continuity and uniformity of the microstructure. Moreover, owing to the different work hardening mechanisms of upper bainite and pearlite, the plastic deformations of upper bainite and pearlite were incompatible, which induced and promoted the formation of fatigue cracks in the nonuniform microstructure and further accelerated fatigue wear.