METHOD FOR FORMING HARD METAL CEMENTED CARBIDE LAYER BY WELDING WORK PIECES WITH CEMENTED CARBIDE POWDER

摘要

The present invention relates to a method for forming an ultra-hard layer on a surface of a base metal which crushes a shaped body of an ultra-hard alloy made of a material such as tungsten carbide (WC), titanium carbide (TiC), etc. and used for cutting metal in a lathe, milling, and other machine tools by arc-welding to use a crushed particulate material to form a surface layer having wear resistance and impact resistance. The method for forming an ultra-hard layer by fusing crushed particles of a shaped body of an ultra-hard alloy into a base metal comprises: a step of grinding or crushing a discarded ultra-hard alloy to prepare ultra-hard particles; a step of placing the ultra-hard particles on a base metal, whose particle diameter is 2-4 mm if a thickness of the base metal is 5 mm, and 1-3 mm if the thickness of the base metal is thinner than or equal to 5 mm; a step of melting the base metal on which the ultra-hard particles are placed, the ultra-hard particles, and a small amount hard lead powder together by arc-welding to form a welded overlay layer; a step of uniformly distributing the ultra-hard particles in a molten pool before the molten pool cools down after the welded overlay layer is formed by arc-welding, and distributing the ultra-hard particles of a diameter of 1 mm or smaller in a thickness of 1-2 mm on the molten pool; and a step of performing a post heat treatment on an alloy coating layer formed by the welded overlay layer.