采用化学成分分析、酸洗低倍检验、金相检验及硬度测试等方法对轴承外圈沟道表面的开裂原因进行了分析。结果表明: 轴承外圈沟道表面裂纹为磨削裂纹，主要是因为在磨削时实际进磨量大,砂轮修磨不良,加之轴承外圈回火不充分,造成轴承外圈沟道表面磨削烧伤并产生了磨削裂纹。

Surface cracking reason of the bearing cup groove was analyzed by means of chemical composition analysis, pickling and macrographic examination, microstructure examination and hardness test. The results show that the surface cracking of the bearing cup groove was the grinding cracking. The large amount of grinding, wear-out grinding wheel and shortage of temper resulted in the grinding burn and the production of grinding cracks on the surface of bearing cup groove.