Numerical Simulation On Electron Beam Welding Temperature Field And Distortion Of Heat-resisting Superalloy Annual Element

Vacuum electron beam welding joint forming quality is good, small deformation,in the aerospace, automotive and other fields has been very good applications.However, with its welding aviation engine when annular thin-walled box class, is stilllikely to random welding residual deformation, the influence on the performance ofthe engine assembly and its use. Annular thin wall parts was optimized by usingnumerical simulation technology of welding process and controlling weldingdeformation, has important theoretical and practical significance. In this paper, theGH4169heat-resisting superalloy was investigated circular pieces of vacuum electronbeam welding temperature field, stress field and the residual deformation in the studyof numerical simulation.In this paper, according to the characteristics of electron beam welding heateffect, adopted by the Gauss surface heat source and projectile heat sourcecombination of composite heat source model. Based on SYSWELD software platform,the appliacation of FORTRAN language for composite heat source model is foundedby secondary development, the successful implementation of this heat source modelcan be used in the software of SYSWELD. Fusion line morphology obtained by platebutt experiment, adjusting the simulation heat source parameters, to a certain processunder the condition of heat-resisting superalloy ring piece of electron beam weldingtemperature field, stress field and deformation are simulated.Numerical simulation results show that the composite heat source model tosimulate the welding temperature field is consistent with the actual situation, thewelding thermal cycle curves are in conformity with the characteristics of electronbeam welding.Annual element in all directions of the residual stress distributionrelated to the position, the axial stress near the weld performance for largercompressive stress, the stress value at the end of circular pieces of close to zero;longitudinal residual stress near the weld center characterized by smaller tensile stress,far from the center of weld is greater compressive stress, at the end of annular parts isclose to zero; weld center on the direction of thickness of ring surface stress is lowerthan that of the circular pieces of internal about20MPa. Through the analysis of thestress of all directions can be concluded that the residual stress in the vicinity of the weld center change drastically, and the area far from the center of weld residual stressis small changes, or even close to zero value, distribution in comparison with thetheory.Backstep welding can reduce welding heat affected zone, and then reducewelding deformation, therefore, put forward by backstep welding way back in order toreduce annular element electron beam welding deformation. This paper compared thetwo kinds of welding mode ring parts after welding deformation, segmented outcompared with continuous welding, the welding ring in all directions of displacementchange are reduced, the maximum of annular axial deformation from0.016mm to0.0134mm, fell by16.25%, and the minimum value changed from-0.11mm to-0.08mm, numerical reduced27.27%; roundness of ring decreased from0.34%to0.25%, decreased by26.47%, so the higher requirements for the roundness of the ringor other side weld circular precision instruments,can be used when welding backstepwelding.