材料为20CrMnTi钢的六方轴渗碳淬火后,在磨削时其表面产生了严重的裂纹。采用宏观检验、金相检验以及硬度测试等方法, 对六方轴表面裂纹产生的原因进行了分析。结果表明: 六方轴表面裂纹是因为砂轮修理不平整以及磨削工艺参数选择不合理, 使工件表面产生了严重的磨削烧伤, 当磨削形变应力、热应力和组织应力综合作用超过材料的抗断强度时, 就形成了裂纹。最后提出了改进措施。

During grinding the cracks were created on the surface of carburized and quenched six square shaft manufactured with 20CrMnTi steel. The reasons were analyzed by means of macroscopic examination, metallographic examination and hardness test. The results showed that severely grinding burnt on the surface was originated from the repaired unsmoothly by abrasion wheel and inappropriate grinding parameters. When the tensile strength was less than the integrated stress during grinding, heating and cooling and phases transformation, the cracks emerging. Moreover, improvement measures were proposed.