| 摘要 |
PURPOSE: A high-speed tool steel gear cutting tool is provided in which fractures or chipping (minute fractures) do not occur at the cutting edge even when performing gear cutting at high-speed, and which realizes excellent cutting performance over long periods, and a manufacturing method therefor is provided. CONSTITUTION: The high-speed tool steel gear cutting tool is characterized in that it has been subjected to a process for preventing the occurrence of fracture or chipping of the cutting edge. The method of manufacturing a high-speed tool steel gear cutting tool comprises a step for quenching a tool material comprising high-speed tool steel and which has been rough processed to a shape corresponding to a final shape of a gear cutting tool, to transform a structure of the tool material into martensite; tempering the tool material after quenching to transform any residual austenite dispersively distributed throughout a matrix of the martensite structure formed by the quenching, into martensite; and finishing the tool material after tempering to a final shape, wherein the tool material after quenching is subjected to sub-zero treatment involving cooling and holding at a temperature of less than -150 deg.C., and transforming any residual austenite which is dispersively distributed throughout the matrix into martensite, to thereby transform the structure of the tool material after tempering into a structure in which residual austenite which is a starting point for chipping at the time of high-speed gear cutting does not exist in the matrix of the martensite. |
