Arc stability study at the limit mode of welding with coated electrodes

This paper shows the results of experiments to study the effect of the auxiliary voltage with frequency fi= 40000Hz on the stability of arc discharge at the limit mode of the welding process with single, coated electrodes. This effective method of connecting rolled and prefabricated elements of metal structures has found widespread use in their installation, manufacture and repair in the construction of various facilities: industrial and civil purposes, thermal and nuclear power facilities for responsible purposes. In this regard, the increase in the quality and technological, strength parameters of welds, the productivity of the manufacturing metal structure process, is largely associated with welding modes and an increase in the stability of arc discharge as an important element of the system: "power source-arc-welding tub-product." Improving the performance of the welding process under consideration is particularly important under mounting conditions in conjunction with its stability is an important task on the agenda. When performing the study, the following criteria and their values   regarding the stability of the welding arc were taken into account, such as: lexpl - rupture length in mm, coefficients of variation: KV(Iwd) - welding current, KV(Uwd) - voltage, qt - constant time, as well as their numerical values were obtained. The obtained numerical values of the above criteria were obtained based on the analysis of graphs (oscillograms) of the dependence of the electric current (Iwd, A) and the voltage (Uwd, V) of the arc on the time of the process duration (t, sec). The obtained results of the analysis indicate an increase in stability, a decrease in inertia of the deviation of the resistance (conductivity) of the welding arc when the auxiliary voltage is applied with a frequency of fi = 40000Hz at the limit mode of welding with coated electrodes.