Study On Laser Welding Process Of Body-In-White Welding Seam

Due to its large energy density,small welding distortion and high welding accuracy,laser welding is increasingly valued by the modern automobile manufacturing industry.In order to reduce the welding body deformation,improve the body strength,reduce body weight and fuel consumption,we tested the lap weld of the company's various models of the feasibility of laser welding.According to the structural characteristics of the white body of our company,we select typical lap joints such as lap joint of car body floor and stringer,overlapping lap joint between roof and side and trunk lid,Welding,laser welding wire melting and laser brazing methods of these three typical lap joints were laser welding specimens.The welded joint strength,tightness and other properties were tested,and the joint microstructure was observed and analyzed.The influence of laser power,welding speed,defocusing amount,wire feeding speed and other factors on the quality of welded joints was studied and discussed,and the optimal welding parameters were obtained.The results show that the parameters of laser fusion welding are: power 4.0kW,welding speed 35 mm / s,defocus amount + 4mm;laser welding process parameters: power 3.3kW,welding speed 3.4m / min,wire feed speed 1.8 m /min,the amount of defocus + 2mm;laser brazing process parameters: power 3.4kW,welding speed 1.4m / min,wire feeding speed 2.2m / min,defocus amount +45 mm.Have access to better performance and organization of welded joints.This will lay a solid foundation for the further application of laser welding body in practical engineering.