Tungsten Electrode Fracture in Submerged Arc Welding Process

The article describes the results of studies on the fracture of tungsten electrodes with an increased arc discharge stabilization rate during the submerged arc welding of titanium structures. The complexity of welding is due to thick-walled parts and a current rate of more than 1600 A. Under this mode, the changes in the geometry of a penetrated electrode and destruction of its working zone occur. It results in major defects—formation of higher melting inclusions in welding joints. The X-ray analysis was used to study welding joints for Ti–Al–Zn. The influence of welding modes and chemical composition of electrodes with 1.1–1.4% LaO and Y₂O₃ added on the erosion wear and destruction of the working edge of electrodes as well as the presence of tungsten inclusions in welding joints were identified. The chemical composition of the electrode material was tested by means of spectral analysis. Using the research results, the stages of the process reflecting the mechanism of destruction of lanthanum/yttrium oxide tungsten electrodes in the submerged arc welding of thick-walled titanium structures were described.