GCr15轴承钢零件表面缺陷分析

Surface Defect Analysis of GCr15 Bearing Steel Parts

轧钢厂生产的GCr15热轧圆钢,用户在使用过程中发现有细小线状裂纹缺陷的存在。取样采用宏观检验、光谱分析、非金属夹杂物检验、金相分析及能谱分析等方法对缺陷原因进行分析。结果表明:近裂纹处夹杂物超标准要求,裂纹缝隙内有灰色氧化物,裂纹大多沿晶或穿晶开裂,裂纹缝隙边缘无明显脱碳现象,正常处金相组织为回火索氏体+粒状碳化物,零件表面裂纹的特征符合淬火裂纹特征。

In the process of GCr15 hot rolled round steel produced by rolling mill,the users found the existence of fine linear crack defect.The causes of defects were analyzed by means of macroscopic inspection,spectral analysis,non-metallic inclusion inspection,metallographic analysis and energy spectrum analysis.The results show that the inclusion near the crack exceeds the standard requirements,there are gray oxides in the crack cracks,most cracks crack intergranular or transgranular cracking,no obvious decarburization phenomenon at the crack crack edge,the normal microstructure is tempered sostenite+granular carbide,the surface crack of the part is consistent with the quenching crack.