38CrMoAl钢螺杆氮化表面剥落原因分析

Cause analysis of nitriding surface spalling of 38CrMoAl steel screw

在生产螺杆过程中,螺杆表面出现剥落麻点现象,通过宏观、扫描电镜、金相显微镜和光谱等方法对螺杆氮化表面剥落原因进行分析,结果表明:螺杆表面出现剥落麻点的原因是由于氮化处理前磨削至局部螺纹棱角处时温度偏高,使棱角处及其附近的表面及浅表层产生轻微的沿晶裂纹,在后续磨削过程中,棱角处易剥落形成麻点。

During the production of the screw rod,the surface of the screw rod appeared peeled off. Macroscopic,scanning electron microscope,metallographic microscope and spectroscopy and other methods were used to analyze the causes of peeling off the nitriding surface of the screw. The results showed that the reason for peeling off of the pitting on the surface of the screw was that the temperature was too high when grinding to the corner of the local screw thread before nitriding treatment,so that the slight intergranular cracks appeared at the corners,and its nearby surfaces and the shallow surface layer. With subsequent grinding,the corners were easily peeled off to form pitting.