通过对20Cr Mn Mo钢试棒进行渗碳后在不同温度和含水量硝盐浴中的淬火试验,得到和端淬距离对应的心部硬度值,进而计算出硝盐浴的淬火烈度,分析了影响硝盐浴淬火烈度的因素以及淬火烈度对渗碳淬火工件临界碳含量的影响。结果表明,在盐浴温度为170~200℃范围内,硝盐浴温度越高,淬火烈度越低;在含水量为0.7%~0.9%范围内,含水量越高,淬火烈度越高;盐浴搅拌速度越快,淬火烈度越高。随着硝盐浴淬火烈度提高,20Cr Mn Mo钢渗碳淬火工件临界碳含量降低。 Through the quenching test of 20Cr Mn Mo steel bars after carburizing at different temperature and water content in salt bath, the hardness values ​​of the heart parts corresponding to the distance of end quenching were obtained, and then the quenching intensity of the salt bath was calculated. The factors influencing the intensity of quenching of salt bath and the influence of quenching intensity on the critical carbon content of carburized and quenched workpiece. The results show that the higher the temperature of salt bath is, the higher the temperature of the salt bath is, the lower the quenching intensity is; the higher the water content is, the higher the quenching intensity is in the range of 0.7% ~ 0.9% The faster the bath is agitated, the higher the quenching intensity. With the increase of quenching intensity of the nitrate bath, the critical carbon content of 20Cr Mn Mo steel carburized quenched workpiece decreased.