LAUSR

ABSTRACT Welded copper-steel joints work in various industries: metallurgy, electrometallurgy, continuous casting machines, electroslag welding moulds, electrical production, etc. Reducing the risk of defects in welds and increasing efficiency are the urgent tasks for welders. One of the reasons for the formation of defects during the welding of copper with steel is the problem of penetration of copper into the microcracks of the steel part. Analysis of all factors and identification of the main causes of copper penetration is necessary to reduce the formation of weld defects. The thermodynamic investigations of the concentration dependence of copper and steel on the permeability of copper and the formation of defects were performed in the work. The experimental studies of the microstructure, mechanical properties and characteristics of the welds have been done through the cutting of the samples across the weld. The study of the plasticity condition failure for copper was performed at elevated welding temperatures. The basic three factors, which strongly influence permeability of copper, have been identified and analysed. The possible ways for reducing the risk of defect formation during welding of dissimilar metals with copper and with steel have been proposed.