Heat transfer of pulsed arc as a function of current frequency

Summary form only given: In welding society, the relation between welding parameters and welding phenomena is complicated because arc welding quality depends on the bead shape, welding speed and so on. Pulsed arc welding is controlled by current waveform, and it also controls the heat input to the material in order to increase the weld of sheet material in welding society. The welding parameters have been chosen by experience such as base and peak current, current frequency and pulse width ratio. Low frequency pulse current less than 10 Hz in pulsed TIG welding is often used in order to control the heat input to the material. However, the relation between heat transfer to the anode and welding parameters has not been reported previously. In this paper, the input power, heat transfer and heat efficiency to the anode was measured, and characteristic of the heat transfer of pulsed arc was elucidated. Pulsed arc was generated by the DC pulsed power supply at the base-peak current of 50-100 A in atmospheric pressure and ambient gas Ar. Heat transfer and heat efficiency of pulsed arc were measured as a function of current frequency. It was measured in the case of the current frequency from 0.1 to 10 Hz because the heat transfer to the anode can only be measured in low frequency. The pulse width ratio which one of current parameters was 50% constant. Arc voltage and heat transfer to the anode were measured by Lab VIEW system and K type thermocouple. As a result, mean heat transfer increases with increasing the current frequency because the pulse rise time decreases with increasing the current frequency. The heat efficiency was almost constant as a function of current frequency. Therefore, the heat transfer depends on the peak current time and current rising time.