ELECTROSLAG WELDING METHOD

PURPOSE:To improve considerably operating efficiency by build-up welding preliminarily the narrow part between a base metal and water-cooled backing strips thereby preventing slag inclusion and eliminating the need for post-repair. CONSTITUTION:A base metal 20 is first build-up welded to form build-up parts 21, 21 and the surfaces thereof are finished. The build-up welded material 20 and a base metal 22 to be welded are spaced and placed to face each other and water-cooled backing plates 23 are pressed onto both sides of the gap to form a space S. An electrode part 24 is inserted into the molten slab 26 in the space S and electricity is conducted thereto to melt the materials 20, 22, the part 21 and the part 24 so that the molten metal is deposited under the bath of the slag 26. The molten metal is cooled by the plates 23 to end welding. The need for the post repair is thus eliminated without generating a welding defect such as inclusion of slag, etc. and the operating efficiency is considerably improved.