论文部分内容阅读
对高碳钢和高碳合金钢进行热处理时,由于马氏体的转变终止温度(即MZ点)位于零度以下,所以,尽管用大于临界冷却速度的冷却剂进行冷却(即淬火),其淬火组织中还会保留一部分残余奥氏体。这对某些尺寸稳定性要求高的零件(如精密丝杠、轴承、量具等)来说是不允许的。因为这些零件经淬火后残留下来的奥氏体,在使用过程中还会发生向马氏体的转变,因而造成尺寸胀大、精度下降的不良后果。因此,必须把淬火零件中的残余奥氏体减少到最
In the heat treatment of high-carbon and high-carbon alloy steels, the martensite transformation termination temperature (ie MZ point) is below zero, so although the cooling (ie, quenching) is performed with a coolant greater than the critical cooling rate, the quench The organization will retain part of the retained austenite. This may not be acceptable for some parts that require high dimensional stability (eg precision screws, bearings, gages, etc.). Because these parts of the austenite left after quenching, in the course of the transformation will occur to the martensite, resulting in swollen size, the accuracy of the adverse consequences. Therefore, the residual austenite in quenched parts must be reduced to the maximum