Effect of Shot-Peening on the Wear Behavior of Two Types of High Manganese Austenitic Steel

In this research, the effect of shot-peening treatment on the wear behavior of two types of high manganese austenitic steel (Fe-7Mn-0.6Si- 1.2C and Fe-17Mn-0.6Si-1.2C) was investigated. In this regard, two samples with various manganese contents of 7 and 17 weight percent are cast, respectively. In order to achieve a uniform structure of austenite into all samples, solution-annealing process is performed at temperature of 1100°C during 2h. Micro hardness measurement and tensile testing as well as wear test according to the rubber wheel-dry sand method are conducted on all heat-treated samples. Surfacing hardening treatment by using of shot- peening equipment is done during 15 and 30 mines on all samples. The results showed that when the percentage of manganese increased from 7 to 17% in the heat-treated samples, hardness and tensile strength values are increased and improved about 27% and 10%, respectively. The surface hardness of high manganese austenite steels is increased due to the applying surface work hardening with shot-pinning treatment. Thus, the highest hardness is observed in the shot-peened sample at time of 30 min. however, the highest hardness and wear %resistance are determined in the sample containing 7%Mn. The investigation of worn surfaces showed that the wear mechanism was abrasive mechanism. Moreover, the amount of and the depth of grooves are reduced with increasing of hardness values.