Effects of Austempering and Martempering Heat Treatments on wear Behavior of Cr-Mo Steels (FMU-226) Used in Mills Liner

In order to investigate the effect of heat treatment on wear characteristics of Cr-Mo wear resistant steel, the specimens were austempered and martempered at 300oC and 200oC respectively for, , 30, and 120 minutes and the wear properties of the specimens were compared with those observed in common cycle in industry (compressed air quench). Dry sliding wear tests have been conducted using a pin-on-disk machine under different normal loads of 57.8, 81.3 and 104.8 at a constant sliding speed of 1.20 m/s. The scanning electron microscope (SEM) and X- ray diffraction (XRD) analysis of surface and wear debris of specimens shows that wear mechanism was mainly mild oxidative in all samples, however, delamination and plasticity-dominated wear mechanisms have been seen in high loads. The friction, wear rate and wear coefficient of the steels, have been explained with respect to microstructure and the wear mechanism. The comparison of wear rates shows that by using austempering and especially martempering process, wear resistance of this steel increases considerably.