QT800—2凸轮轴磨裂产生的原因及对策

通过金相分析，表面应力测定及热处理工艺实验研究了ＱＴ８００－２凸轮轴等温淬火后磨削裂纹产生的原因及解决办法。结果表明，组织中存在的脆性相、马氏体与残余奥氏体的成分不均匀区域及磨削产生的温度和应力是导致其磨削裂纹产生的主要原因，这些缺陷可以分别通过改善热处理工艺，减少磨削加工余量进给量等措施得到改善。

An Analysis of Grinding Cracks of QT80O-2 Cam Shaft

An analysis is made for the reason of forming grinding cracks of QT8OO- 2 cam shaft after isothermalquenching by metallographic measureinents,surface residual stress meaeurements etc. The method to solve the prob-lem is also presented according to heat treatment tests. It is shown that the existence of brittle phases, inhomogeneousregion of composition in martensite and residual austenite and the high temperature and stress produced by grindingare the main reasons leading to forming of grinding cracks,which can be improved by changing heat treatment scheduleand lowering grinding allowance and feeds.