COPPER-BASED INSERT METAL FOR WELDING BETWEEN CEMENTED CARBIDE ALLOY CONTAINING COBALT AND STRUCTURAL STEEL AND METHOD FOR WELDING CEMENTED CARBIDE ALLOY AND STRUCTURAL STEEL BY USING THE SAME

PURPOSE: A copper-based insert metal for welding between a cemented carbide alloy containing cobalt and a structural steel and method for welding the cemented carbide alloy and the structural steel by using the same are provided to effect reduction of stress and suppression of brittleness in a welding interface of a welded material which is formed by welding a cemented carbide alloy and a structural steel, to obtain a precise welded material, and to improve considerable bonding strength. CONSTITUTION: A copper-based insert metal for welding between a cemented carbide alloy containing cobalt and a structural steel and method for welding the cemented carbide alloy and the structural steel by using the same utilizes a copper thin plate in which zinc(Zn) and silicon(Si) are added by 5% or less and on which nickel(Ni) is plated with a prescribed thickness. The method is characterized in that a cemented carbide alloy containing 4 to 13% of cobalt and a structural steel are welded at temperature of 1000 to 1150deg.C for 10 to 60 minutes under vacuum or a certain inert gas (such as Ar gas or Ne gas) environment by using the insert metal, and then the welded material is cooled at 40deg.C/sec. or less or in an oil heated at a range between 100 and 800deg.C. When a cemented carbide alloy such as ceramic and a structural steel that is a ferrite-based metal are welded by using the copper-based insert metal, the welded material is formed precisely with a considerable bonding strength and can be made with low cost.