| 摘要 |
PROBLEM TO BE SOLVED: To provide a vacuum carburizing method and a vacuum carburizing device which can sufficiently improve the hardness and toughness of a workpiece. SOLUTION: The vacuum carburizing method comprises: a temperature increasing stage where a workpiece in a heating chamber is increased to a prescribed temperature; a carburizing stage where, in a state where the temperature of the workpiece reaches the prescribed temperature, a gas for carburizing is fed into the heating chamber storing the workpiece from a state where the inside of the heating chamber is decompressed to an extra-low pressure atmosphere, thus the workpiece is carburized; a diffusing stage where, after the carburizing stage, the feed of the gas for carburizing is stopped, and carbon as an element composing the gas for carburizing is diffused from the surface of the workpiece to the inside; and a cooling stage where, after the diffusing stage, the workpiece is cooled. The method is characterized in that the carburizing stage and the diffusing stage are alternately repeated for a plurality of times. COPYRIGHT: (C)2010,JPO&INPIT |
