Effect of Incident Angle on Laser Melted Layer Microstructure and Properties

Laser melting treatment with different incident angles was carried out by using HL-1500 CO2 laser processing machine on 40Cr steel.The microstructure and properties were analyzed by means of scanning electron microscopy,X-ray diffraction,microhardness meter,potentiostat and abrasive-wear tester.The results indicate that the melted layer was composed of surface,middle layer and transition layer.As the incident angle increasing,the melted layer microstructure became coarser.With increasing the laser incident angle,the microhardness of the melted layer gradually decreased,the depth of the melted layer became shallower and the wear resistance showed decreasing trend.The corrosion resistance of laser melting layer was improved.