磨削裂纹形成机理商榷

Discussion of Grinding Crack Forming Mechanism

通常认为工件磨削裂纹是由于磨削热造成工件局部高温，且温升速度很快，至使工件再次奥氏体化淬火成马氏体，产生组织应力，当组织应力超过材料强度时，便产生裂纹。但此理论不能解释下述现象：条状裂纹为什么与磨削方向垂直？为什么裂纹多成条状，且沿晶穿晶而过……？本文在大量试验中，发现工件磨刚时存在“瞬间拉应力”，并在此基础上提出磨裂机理新观点：在磨削过程中，磨削表面产生热应力、瞬间拉应力和组织应力，其合力或其中任一应力超过材料表面的断裂强度时，将产生裂纹。附图2幅，表1个，参考文献篇。

Formation of grinding cracks is not only the result of structural stressand thermal stress occurred at ground surface of work piece, but also the result of instuntu-neous tensile stress which plays a leading role. Other wise,it is also in close relationship withfracture strength of matCrial. The mathematical expression of law of grinding crack forma-tion is summarized and the method of restraining grinding crack formation and spread is intro-duced.