Research On TIG Welding Arc Characteristics Under The Action Of High Frequency Dual Pulses, The Current Pulse And Magnetic Pulse

Tungsten argon arc welding (TIG welding) is widely used in nuclear power stationand aerospace fields by virtue of the advantages of the arc stability, no splash, almost allmetal or alloy welding and so on. However, there exist some shortcomings in TIG weldingsuch as arc energy and heat decentralization, penetration shallow and a low efficiency.When the speed of welding travel is too fast, the defects such as undercut and convex edgewill be generated. For this purpose, a kind of high frequency dual pulses TIG arc weldingmethod is put forward in the paper which can improve the arc energy and increase thepenetration effectively with the combination of high frequency current pulse and additionalmagnetic field pulse. This method can not only achieve the purpose of improving thephysical properties of arc by controlling the arc shape, but also involves the additionaldevice of low cost, small in size and efficient to administer. At present, research on theeffect of the electromagnetic coupling on the welding arc has not formed a completesystem, and welding process parameters optimization study is very rough. Therefore, it hasimportant theoretical significance and great practical application value that carries out theresearch of TIG welding arc behaviors under high frequency dual pulses.In this article, self-made circular concentric split anode device is used to test arc heatdistribution under different dual pulse parameters. Using self-made water-cooled copperanode test arc pressure radial distribution under different dual pulse parameters. We takethe change of arc shape by high speed camera and test current density distribution by theprobe method under the action of dual pulses. The experimental results show: theperformances of arc under the action of high frequency dual pulses are significantly higherthan those which are under the action of single pulse or free arc. When the current effectivevalue of80A, current pulse frequency of500Hz, magnetic intensity of30mT, magneticpulse frequency of about1500Hz, the heat distribution coefficient increase from39.52%to66.07%. Moreover, the distribution characteristics of arc pressure and current density are itmhep rsoavmese.f roCmen2te0rA p mremssure increases from0.35KPa to0.54KPa and current density-2to30.9A mm-2. The rotation radius of arc reduces significantly.As the result, the arc shape is compressed from cone to columnar.The welding line formation tests delicate that it leads to weld forming well, weldwidth small, penetration deep outstandingly.