STARTING METHOD OF ELECTROSLAG WELDING

摘要

PURPOSE:To prevent the defect near the starting position for welding and to obtain a defectless weld metal by supplying a shielding gas to the weld zone during the time from just prior to starting of welding until a flux melts to form a slag bath after starting of welding. CONSTITUTION:A shielding gaseous atmosphere is maintained in the base of a groove by supplying a shielding gas 8 through a tube 9 to the inside of the groove prior to welding and thereafter a wire 6 is fed to generate an arc. Welding is then progressed by charging a flux to the groove to form a slag bath 12 after generation of the arc and the supply of the gas 8 is continued until the slag bath 12 is formed to a suitable depth. Since a molten metal 11 is shielded from the atm. air until electroslag welding is started, the weld metal 10 contg. no blowholes is obtainable. Carbon dioxide or a gaseous mixture composed of carbon dioxide and argon is used for the gas 8.