Research On Impact Property Of 40cr Steel Under Different Tempering Conditions

40Cr is a kind of steel that is often used for semiaxis in heavy duty trucks, therefore high impact property of 40Cr steel is requested to adjust the heavy-duty machine's working environment. In this study, the samples of 40Cr steel were heated under normal tempering temperature and quenched in air, water and oil, respectively. The experiments were carried out through charpy impact and microhardness analysis. It was indicated by experiments that water was more helpful to receive higher impact toughness as the tempering cooling medium than air and oil. At the same time, the intensity and hardness of 40Cr steel were enough to meet the heavy-duty machine semiaxis requirements.