Patent ID: 7588620
Filing Date: 2009-09-15
Classification: B22F,C22C,Y10T

Abstract:
1. A cutting tool comprising a cemented carbide, a composition of the cemented carbide comprising: 5.0 to 15.0 mass % of cobalt; 0.8 to 4.5 mass % of niobium in terms of carbide; 0.5 to 16.0 mass % of at least one selected from carbide (except for tungsten carbide), nitride, and carbon nitride which are selected from the group consisting of metals of the groups IV, V, and VI in the periodic table, except for niobium; 0.01 to 0.08 mass % of oxygen; and the rest consisted of tungsten carbide and unavoidable impurities, the cemented carbide comprising a structure in which a tungsten carbide phase and a B1-type solid solution phase being expressed by M(CNO) or M(CO) where “M” is at least one selected from the group consisting of the group IV, V, and VI in the periodic table, containing niobium as being essential, and containing oxygen at a rate of 1 to 4 atomic % are bound by a binder phase composed mainly of the cobalt.