| 摘要 |
PURPOSE: To prevent or reduce problems of conventional technologies including high production cost generated when performing HIP sintering to maintain fine grain size of cemented carbide, and to provide a cemented carbide insert having high toughness and high deformation resistance and a method for manufacturing the same. CONSTITUTION: In a manufacturing method of fine WC-Co cemented carbide comprising mixing step, milling step and sintering step according to an ordinary powder metallurgy process, the method is characterized in that the sintering step is performed by introducing nitrogen into a sintering atmosphere at a temperature of less than 1,000 deg.C and at a pressure of more than 0.5 atmospheric pressure, preferably at a pressure of more than 0.75 atmospheric pressure, before pore closure after dewaxing, wherein the overall sintering process is performed in nitrogen, wherein nitrogen is substituted for a protection atmosphere, i.e., argon or vacuum after the pore closure, wherein metals of IVb, Vb and/or VIb groups of the periodic table, compounds of the metals except nitrides, preferably Cr, V and/or Ta, most preferably Cr and/or Ta are added as a grain growing inhibitor, wherein the compounds do not contain nitrogen, and wherein the compounds are carbides.
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