大型回转支承滚道裂纹机理分析

Analysis of Crack Mechanism of Large Slewing Bearing Raceways

在某产品部件大型回转支承使用较长时间后,对回转支承滚道进行磁粉探伤检查发现裂纹。采用宏观观察、扫描电镜观察、金相分析及能谱分析对回转支承滚道裂纹进行了分析。分析结果表明:滚道表面裂纹性质为淬火裂纹,位于硬化层内部,在后续使用过程中发生了应力腐蚀扩展,最终出现肉眼可见的裂纹缺陷。

After a large slewing bearing of a product component was used for a long time,the slewing bearing raceway was inspected by magnetic particle inspection and cracks were found.Macroscopic observation,scanning electron microscope observation,metallographic analysis and energy spectrum analysis are used to analyze the cracks in the slewing ring raceway.The analysis results show that the nature of the cracks on the surface of the raceway is quenching cracks,which are located inside the hardened layer.During the subsequent use,stress corrosion propagation occurs,and finally visible crack defects appear.