曲轴疲劳试样表面磁痕分析

Analysis of Magnetic Traces on Crankshaft Fatigue Testing Specimen

采用宏观和微观检验等手段对曲轴疲劳试样不同部位磁痕产生的原因进行了分析。结果表明:磁痕是由于带状组织、疲劳裂纹和磨削裂纹等原因造成的。磨削裂纹主要是由于磨削时摩擦应力过大造成的。原材料中存在较严重的带状组织,导致淬火组织和残余应力不均匀,对磨削裂纹的产生起到了促进作用。

The reason of the magnetic traces on the different part of crankshaft fatigue testing specimen had been analyzed by means of macroscopic and microscopic examination. The results showed that the magnetic traces were caused by the banded structure,fatigue crack and grinding crack.The grinding cracks were caused by the prodigious grinding stress.The banded structure was very serious in the raw material,causing the uneven distribution of the quenching structure and residual stress,which accelerated the initiation of grinding crack.