我厂热处理车间在生产中经常遇到一些形状复杂或截面尺寸变化较大易造成淬火开裂和一些直径较小的细长易变形的零件。为防止淬火开裂过去一直采用石棉绳包扎保护,用水淬油冷处理。易变形零件则采用较低的温度加热或加热后先在空气中缓冷然后用水淬油冷。这些方法虽然能解决一些问题,但是要求具有熟练的操作技术和较丰富的实践经验,同时劳动强度大,包扎工件的辅助时间长,这对于多快好省地发展生产是不相适应的。我们认为,这些零件易造成开裂和变形主要是和冷却液的冷却速度有关,因 I plant heat treatment plant in the production often encounter some complex shape or larger cross-sectional size can easily lead to quenching and cracking and some small diameter slender deformation parts. In order to prevent quenching and cracking in the past has been used asbestos rope bandage protection, water quenching oil cold treatment. Deformable parts are used to lower the temperature heating or heating in the air after the slow cooling water quenching oil cold. Although these methods can solve some problems, they require skillful operation techniques and rich practical experience, and at the same time, labor-intensive and long-time auxiliary work of dressing workpieces are not suitable for developing production more quickly and economically. We think that these parts are easy to cause cracking and deformation mainly due to the cooling rate of the coolant, because