Calculation and experimental research of static and dynamic volt-ampere characteristics of argon arc with refractory cathode

Abstract

Well-grounded selection of optimum modes of non-consumable pulse-arc welding requires investigation of dynamics of pulsed arc burning. Proposed earlier model of nonstationary arc with distributed parameters, due to large computing expenses, allows considering effect on arc of only single current pulse. Whereas, investigation of dynamic characteristics of the arc in supply of batches of high-frequency pulses of welding current is of practical interest. In this connection, it is interesting to develop an arc dynamic model with lumped parameters, which does not have limitations from point of view of amount of computations and allows high accuracy tracing of the dynamics of change of characteristics in arc with refractory cathode at high-frequency current modulation. The same data were received for comparison using calculation method based on the model with distributed parameters. Arc column time constant was determined based on calculation data of dynamics of arc voltage change, received employing the model with distributed parameters. In total complex of carried research and experimental investigations allowed working out an algorithms of application of the model with lumped parameters and identifying them. The results are given on expemental investigations of dynamics of change of current and arc voltage in high-frequency non-consumable pulse-arc welding, which are matched with the results of calculations using the model with lumped parameters. 14 Ref., 1 Table, 8 Figures. K e y w o r d s : pulse-arc welding, non-consumable electrode welding, high-frequency pulses, dynamic characteristics of arc, nonstationary arc, arc column, argon arc, refractory cathode