HARD MOUNTING CEMENTED CARBIDE AND PRODUCTION

PROBLEM TO BE SOLVED: To realize a hard mounting having enough hardness by using a build-up welding bar of a cemented carbide which contains a binding metal of a specific ratio, which is composed of a WC-Co base, which is made in a grain like and which has a relative density less than a specific value. SOLUTION: The reason of a cemeted carbide being composed of a WC-Co base is because it is the most suitable material for applying the wear resistance. Further, because an Fe base alloy from a tube after welding or its alloy is acted as a binding metal, the Fe base alloy is made as 2 to 5 % considering the amount. In the time of producing the cemented carbide, press forming is omitted, it is intended to leave in a porous state and its relative density is made less than 98 %. When welding, this porous part is invaded with the Fe base alloy, the boundary of grain-Fe alloy is more strengthened, further, the amount of binding metal is also increased, however, because the original grain has a few content of the binding metal, so the hardness can be kept sufficiently.