The power supply based on MOSFET for electron beam deflection scan has been developed.The equivalent circuit, topology circuit structure,the work principle of drive circuit had been analyzed.The drive waveform of MOSFET,the output current waveform,multiple beam welding effect used the power supply had been detected.The experimental results show that:the circuit can output various driving waveforms.All waveforms can reach the high frequency upto 100 kHz.The frequency of sine wave current can reach 5 kHz.Through adopting three step current wave with frequency upto 3 kHz,the result of three electron beam welding had been achieved.

Welding residual stress is caused in welding.Its release and redistribution greatly affect milling deformation during milling process.In order to study the law of its release and redistribution,the milling finite element modeling of welding workpiece is established.The original residual stress suggested in the milling finite element analysis is obtained by using minimum welding residual stress and them the milling residual stress and deformation of welding workpiece are gained.At last,its release and redistribution and milling deformation are analyzed.

This paper makes a study of the influence of shot peening on welding deformation of heavy transport vehicle frame longitudinal beam,uses MSF-3M stress analysis instrument to measure the residual stress of welding workpieces and measures the deformation of the welded and unwelded workpieces using the 3D-coordinate measuring instrument and then draws the 3D graphics of workpieces by the use of Matlab software.The deformation is analyzed through the standard deviation of its deformation data.It is proved that the welding deformation of the heavy transport vehicle frame longitudinal beam can be improved and controled effectively by shot peening.

The welding temperature field of heavy vehicle frame was simulated using FEA software—ANSYS.The welding temperature FEM of heavy vehicle frame was established.Material property parameter in high temperature was properly chosen.The computer program of the welding temperature simulation was compiled using APDL of FEA software.The method of Gauss heat source and life-death element technique were applied to deal with the moving of heat source and the filling of welding material step by step in simulation.Three dimensional transient welding temperature field and the temperature distribution curves of special points on weldment were gained.The welding temperature field variation of special points on heavy vehicle frame was gained.The temperature measurement test was done to verify the simulated results.The results show that the simulated results were generally agreed with test results.