| Argon tungsten arc welding(TIG welding)is a welding method in which tungsten rod is used as electrode and argon gas is added for protection.Compared with other welding processes,the arc of TIG welding is relatively stable.There is no splash in the welding process,and the welding seam is well formed.It is widely used in aerospace,petrochemical and other manufacturing fields.However,TIG welding also has its own defects.The arc energy density of TIG welding has low deposition speed,low melting depth,and is only suitable for medium and thin plate welding with low welding efficiency.Therefore,in order to improve the welding efficiency of TIG welding,welding workers invented a welding mode with external magnetic field in the process of TIG welding,which use magnetic field to change the arc characteristics and crystallize the pool,so as to improve the welding efficiency and improve the welding quality.In this paper,a high frequency magnetic-controlled power supply is designed and developed by using inverter technology.The power supply can change the action frequency of magnetic field,and the action intensity of magnetic field can be changed by changing the magnitude of excitation current.It is characterized by small volume,light weight,simple operation and convenient adjustment.This paper has designed the main circuit,synchronous circuit,control circuit,feedback circuit and protection circuit of magnetic control power supply.In the course of the design process,the TIG magnetron power source was debugged,and it tested the output waveform of the TIG magnetron power source.Through experimental measurement,the TIG magnetron power supply designed can work continuously and stably,fully meeting the requirements of welding experiment.This article also designed to match the TIG magnetron power head,the design of magnetic head can adjust the direction of magnetic pole number and the change of different types of magnetic field,to solve the existing head device form a single,in the form of a magnetic head can produce a magnetic field,in the welding process if the need to change the magnetic field in the form of the need to replace a new head,complex operation,low efficiency,high cost of the problem.The welding experiment of TIG magnetron power supply was carried out to study the characteristics of TIG welding arc.In the welding process,a high-speed camera was used to synchronously shoot TIG arc,observe the change of the arc shape under the action of magnetic field,and make a comparison with the arc shape simulated by simulation software.The effect of magnetic field on arc pressure was measured.Finally,the weld forming and the microstructure of the welded specimen were studied.The results show that the arc shape under the action of a magnetic field,electric arc pressure and the welding quality has obvious changes,at the same time also once again proved the developed TIG magnetic control power supply can be practical. |
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