Application of pulse welding power sources in electrochemical processes

Abstract

It was determined that area of application of pulse welding power sources for processes of metal flame treatment can be expended. At that continuously rising in price natural gas is substituted by hydrogen-oxygen mixtures or hydrogen. Application of nickel instead of low-carbon steel as electrodes at water electrolysis allowed reducing process voltage to 2.1 V. Dependence of increase of percent content of finer powder fractions (1-50 μm and 1 μm, and less) at increase of frequency of current of anode dissolution was determined. Received results indicate perspectives of investigations in this direction for increase of efficiency of electrochemical processes of hydrogen production as well as micro-and nanopowders for manufacture of welding and brazing powder consumables. Pulse power sources for gas-shielded metal arc welding are widely used in such branches of industry as shipbuilding, chemical-machine building, rocket production, car industry, pipeline construction and many others [1,2]. Frequency of transfer of electrode metal droplets is an important parameter among the different parameters for regulation of process of pulse-arc welding and it usually lies in 30-300 (500) Hz range. Smooth regulation of frequency of welding current pulses allows electrode metal transfer by principle «1 pulse-1 droplet». The E.O. Paton Electric Welding Institute works on development of equipment and technology of pulse-arc processes for a long time. Different types of welding equipment were developed including power sources for pulse-arc welding. They showed themselves good in welding of critical designation structures [3,4]. The main peculiarities of such sources are possibility of smooth regulation of frequency of current pulses from 30 to 300 Hz, duration of pulses 0.5-5.0 ms and amplitude to 850 A.Power sources are used in related technologies, for example, in production of hydrogen-oxygen mixtures for processes of welding, brazing, welding-brazing and operations of flame treatment of metals. Gas generators in indicated processes consist of direct current welding source and electrolytic cell. Possibility of dramatic reduction of consumption of continuously rising in price natural gas and decrease of environment pollution are the advantages of application of hydrogen and hydrogen-oxygen mixtures in flame treatment processes.Besides, one of the variants of significant reduction of costs for welding and brazing consumables are the possibility of in-situ production, for example, of braze pastes of necessary composition with guaranteed quality, by methods of electrochemical dispersion of ferrous, nonferrous and noble metals. Therefore, it is relevant to carry out experimental investigations on increase of efficiency of electrochemical processes due to regulation (increase) of current frequency.The most repeatable in final result processes were selected for performance of experimental investigations of effect of current frequency on some electrochemical processes. First of all, these are the processes essential for power engineerin...