Research On Key Technology Of Welding Residual Stress And Deformation Control Of Engineering Wheels

Engineering wheels are the main carrier and transmission force of the loader.Its manufacturing quality will not only have a direct impact on the important performance indicators such as load carrying capacity,braking force and acceleration,and it may endanger the safety of people.However,due to its large size,complex welds and other reasons,resulting in the residual stress distribution after welding complex,gradient,eliminate difficulties;welding deformation is relatively complex and difficult to control.Therefore,how to control the residual stress and deformation of engineering wheels have become an urgent problem to be solved.In practice,the VSR(Vibratory Stress Relief)is proved to be extremely effective in controlling the residual stress and deformation of welding.However,the mechanism of VSR to eliminate the residual stress and deformation of welding is not recognized as a scientific system,which seriously hinders its elimination of performance.In practical application,due to the lack of system theory knowledge,the development of VSR process and the selection of process parameters can only rely on experience,which will greatly limit the scientific use,popularization and development of VSR technology.For the key technology of welding residual stress and deformation control of engineering wheels,this dissertation mainly solves the problems of welding numerical simulation and VSR.In this dissertation,the engineering joint of the wheels is used as the research object.Based on the finite element analysis software ANSYS,the dynamic simulation of the transient temperature,stress and deformation of the welding process is realized by means of APDL language.The thermal-elastic-plastic model of the temperature field,stress field and strain field in the welding process was studied,then the X-ray residual stress detection technique was used for the comparison.The results show that the residual stress obtained by numerical simulation agrees well with the experimental data,and the change trend is basically the same.Next the relationship between the welding residual stress and deformation,the distribution law and the welding process parameters are analyzed and discussed.By comparing the simulation results of different preheating temperature,it is concluded that the improvement of the preheating temperature can effectively eliminate the welding residual stress and deformation.Through the analysis of the harmonic response of the engineering wheels,the dissertation analyzes the vibration aging process,and obtains the optimal process parameters of the residual stress and deformation control of the engineering wheels through the VSR: the support point,the excitation point,The optimum excitation frequency is 265 Hz and the optimal excitation force is 3KN.Which provides the experimental basis for parameter selection of VSR of engineering wheels.But also for other parts of the VSR process parameters selection method provides a reference.According to the optimum VSR process parameters,the vibration aging test was carried out by using the harmonic spectrum vibration aging method,and the welding residual stress and deformation were controlled.Then the welding residual stress and deformation control effect were evaluated by parametric curve method,residual stress evaluation method and dimensional precision stability evaluation method respectively.The results show that the stress relief effect is obvious,the average stress elimination rate is 14.75%,the stress homogenization rate is 37.21%,the residual stress peak decreases by 57%,and the effect of " And the engineering wheels in the VSR process did not appear large deformation,the main processing surface,the base surface deformation within the allowable range of tolerance.The release of a certain welding residual deformation at the same time get a better dimensional accuracy of stability and resistance to deformation.So that the engineering wheels welding residual stress and deformation has been well controlled.