TECHNOLOGICAL CHARACTERISTICS OF AUTOMATIC SUBMERGED ARC SURFACING WITH HIGH-FREQUENCY OSCILLATIONS OF ELECTRODE END

摘要

Applying to the electrode of HF pulsed displacements, generated by a specially-developed electromechanical generator, allows increasing the efficiency of electrode melting and providing control of geometric parameters of bead in automatic submerged arc surfacing (ASAS). The present work is aimed at the experimental evaluation of the effect of HF electrode oscillations on technological characteristics of the ASAS process of structural steels. It was found that stability of arc process and quality of deposited layer formation in ASAS with HF pulsed displacements of electrode correspond to similar characteristics for surfacing without controlling action. Analysis of oscillograms of current and arc voltage shows that HF electrode oscillations allow controlling electrode metal transfer parameters. The HF electrode end oscillations under the action of pulsed displacements lead to changes in frequency of fluctuations of arc voltage: from 15-20 Hz in natural drop metal transfer to the frequencies without distinctly expressed extremums, which is predetermined by refining of drops, detached from electrode. The increase in frequency of controlling action results in growth of deposition coefficient rate from 15 g/(A·h) without oscillations up to 22.6 g/(A·h) at 320 Hz frequency. The change in amplitude of oscillations from 0.5 up to 3 mm in the frequency range under study allows decreasing the share of base metal in deposited metal at 30% overlapping of beads from 0.25 (surfacing without oscillations) to 0.14.