B-17 RESEARCH ON ALTERATION OF SURFACE MICROSTRUCTURE OF CARBURIZED-QUENCHED STEEL BY SHOT-PEENING(Session: Surface Modification)

抄録

For the purpose of defining the alteration mechanism, we've selected normalized steel S55C that have a relatively similar %C to carburized-quenched steel that got the hardening treatment, and shot-peened the steel. In the experiment, martensite has been observed on the case of normalized steel S55C that was given shot-peening. According to the results of experiment, the conclusion we've reached about the alteration mechanism of the case of carburized-quenched steel caused by shot-peening is that shots thrown on the surface of steel generates frictional heat, which makes the temperature of the case reach the austenite region, and then the case transforms into martensite by self-cooling.