焊接功率对双相1500钢焊接接头组织和性能影响研究OA

A Nd∶YAG laser was used to laser weld dual-phase(DP)1500 steel.The effects of different welding power on the microstructure and mechanical properties of DP1500 steel welded joints were investigated using an optical microscope(OM),a scanning electron microscope(SEM),a transmission electron microscope(TEM),a Rockwell hardness tester,and a universal tensile tester.The effects of different welding powers on the microstructure and mechanical properties of DP1500 steel welded joints were investigated.Through the macro-microstructure characterization,it was found that with the increase of welding power,the melt width increased from 1.39 mm to 2.39 mm,the martensite organization of the thick slats in the weld zone was gradually refined and the orientation distribution was more consistent,and the grain coarsening phenomenon appeared in the heat-affected zone.From the mechanical properties,with the increase of welding power,the yield strength and tensile strength of welded joints are increased and then decreased.In the welding power range of 1.5～3.5 kW,the tensile strength and elongation at break of the welded joints were the best when the welding power was 2 kW,which were 1 310 MPa and 4.29%,respectively.