渗碳齿面裂纹成因分析

Analysis on the Reason of Crack on Carburized Gear Tooth Surface

同批处理的渗碳齿轮在磨齿成形后发现齿面裂纹,通过采用化学分析、宏观分析、金相分析、硬度测试、电镜分析、X射线应力测试、工艺试验等方法对齿面裂纹成因分析,结果表明,由于齿轮渗碳层内有渗氢现象,磨削烧伤后,在内部拉应力作用下产生了氢脆,最终导致齿面收缩开裂,由此提出了预防和改进措施。

Tooth surface cracks are found in the same batch of carburized gears after grinding forming. The reason of tooth surface crack is analyzed by chemical composition analysis, macroscopic analysis, metallographic analysis, hardness test, scanning electron microscope analysis, X-ray residual stress measurement and process test, etc. The result shows that there is the phenomenon of hydrogen penetration in the carburized layer of gear, so that the hydrogen brittleness is occurred under the effect of internal tensile stress after grinding burn, and eventually leads to the shrinkage crack of teeth surface. And the prevention and improvement measures are proposed.