用X射线应力仪测量凸轮轴表面激光淬火相变层的残余应力

Measurement of Residual Stress in Camshaft Phase Transformation Layer by CO₂ Laser Quenching with X-ray Diffraction Stress Tester

摘要: 利用CO2激光对凸轮轴所用材料QT600-3表面进行了淬火处理试验,并用X-350A型X射线应力仪测定其残余应力分布,分析了残余应力的形成机理.结果表明:经CO2激光淬火后QT600-3的显微组织为隐晶马氏体＋石墨,残余应力均为压应力,其值在120 MPa以上,且随着功率的增大而增加;相变层深度随着扫描速率和光斑直径的增加而减小,且随着功率的增大而增加;激光淬火后的材料组织结构比较均匀,有利于提高凸轮轴的使用寿命.

Abstract: The surface of camshaft QT600-3 was processed with CO2 laser quenching,and the residual stress distributions of camshaft by laser quenching were investigated with model X-350A of XRD (X-ray diffraction) stress tester,and the forming mechanism of residual stress is analyzed.The experimental results are shown that the microstructure of QT600-3 by CO2 laser quenching is Aphanitic Martensite+Graphite,and residual stresses are all compressive,which is above 120 MPa,they increase with laser power.The depths of phase transformation layer decrease with scanning speed and spot diameter increase,and they increase with laser power.The material fabric and structure by laser quenching are comparatively uniformity,which is benefited to increase service life of camshaft.