The process of electroslig soldering using electrode powder wires

Abstract

This paper examines the technology and technique of electroslag surfacing, as well as examples of industrial application of electroslag surfacing. This process is based on the release of heat from an electric discharge in a bath of molten flux. Electroslag surfacing is used for the production of bimetallic parts, as well as for obtaining wear-resistant coatings. In the surfacing process, the electric current passes through the molten welding flux, as a result, heat is released, which is necessary to melt the edges of the parts and the electrode. The electrode is fed into a bath consisting of a liquid flux bounded by a melting surface and a special forming device. Graphite, copper or steel pads can serve as a forming device. The fluxes used must have a certain viscosity and electrical conductivity. When using fluxes with low oxidizing power, slight losses of surfacing alloying elements occur. Electrodes for surfacing can be welding wires, tapes or rods of large cross-section. Due to low electrical and thermal conductivity, the temperature reaches more than 2000°C. The speed of melting of the electrode is very high, the melting coefficient reaches 30 g/A h, spattering losses are practically absent. The best conditions for surfacing the base metal and obtaining a deep slag bath are created when the seam is in a vertical position, therefore electroslag surfacing is most often used in combination with forced formation of the weld seam. Surfacing begins and ends with fixing the part on special technological bars, which are then removed from the part. At the beginning, while the process has not yet been established, the deposited layer may be of insufficient quality, this part of the seam remains on the initial strip, at the end of the seam, the strips are used to remove the shrinkage shell.