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

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.