WEAR RESISTANCE EVOLUTION OF GRAPHITE STEEL (GSH48) IN ULTRASONIC PEENING PROCESS

As a very important factor, abrasion resistance is a very important parameter to enhance the working life of rollers. In this study, a wear test was utilized to determine the friction coefficient and the wear resistance of graphite steel rollers. The generation of hard work and compression in the surface layers of the workpiece enhances some mechanical properties such as strength, hardness and smoothness, during the ultrasonic peening technology (UPT) process. An ultrasonic vibrating tool was simulated, built, and installed on a lathe for ultrasonic tapping. The wear resistance of samples improved after the UPT process. The friction coefficient value dropped about 50% showing a decreasing effect of the UPT process. The friction coefficient values of samples before and after the UPT are 0.5 and 0.25, respectively. The results indicate a 36% increase in hardness to a depth of 0.2[Formula: see text]mm from the surface. Also, the width and depth of wear channels decreased after the operation. The mechanism of the wear process and the effect of UPT on the SEM fracture morphology of samples, and the bonding mechanism before and after the UPT process were investigated. Based on the results obtained, strength, wear resistance, life span and wear resistance of samples were improved during the UPT process.