轴承零件热处理普遍采用油作淬火介质。这是因为油在冷却过程中的第三个阶段(对流期),冷却速度特别缓慢,如10~#和20~#机油对流阶段大约从300℃开始,一直持续到室温。轴承钢的马氏体转变温度与冷却速度较小的对流相吻合,从而使轴承零件在淬火过程中变形和开裂的倾向大为减小。但是,由于油的冷却速度慢(650～500℃时为100～120℃/s;300～200℃时为20～500℃/s),淬火时,虽然用手动葫芦将套圈吊入油中,使其在油中 Bearing parts commonly used heat treatment oil quenching medium. This is because the third stage of the oil cooling process (convection), the cooling rate is particularly slow, such as 10 ~ # and 20 ~ # oil convection stage from about 300 ℃, until the room temperature. Bearing steel martensitic transformation temperature and cooling rate of smaller convection coincide, so that the bearing parts in the quenching process greatly reduce the tendency of deformation and cracking. However, since the cooling rate of the oil is slow (100 to 120 ° C / s at 650 to 500 ° C and 20 to 500 ° C / s at 300 to 200 ° C), the ferrule is hung in oil during quenching , Make it in the oil