Abstract: To solve the problem of blind hole carbonization, the carburizing capacity of conventional gas carburizing and vacuum low-pressure carburizing to the blind holes of 20CrMo steel were analyzed and compared. The results show that the carburizing capacity of vacuum low-pressure carburizing to the blind hole is much higher than that of the conventional gas carburizing, and the smaller the size of the blind hole, the higher the vacuum, the better the carburizing capacity is. The different gas states of the conventional gas carburizing and vacuum low-pressure carburizing are the main reasons for the different carburizing capacity of the two processes for blind hole inner surface.

Key words: 20CrMo steel, blind hole, conventional gas carburizing, vacuum low-pressure carburizing