Analysis on Cracking Reason of 35CrMo Round Steel Part during Quenching and Tempering Process

The cracking reasons of 35CrMo round steel part after quenching and tempering process were analyzed by means of macroscopic examination, chemical composition analysis, metallographic examination and so on.The results showed that the appearance of cracks on round steel part was mainly induced by the use of loose part due to inappropriate process technology.In addition, the extension of cracks was promoted resulted from the faster cooling speed.