GAS NITRIDING METHOD AND GAS NITRIDING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a gas nitriding method and a gas nitriding device, wherein more precise control is made possible by allowing embrittling compounds such as triiron mononitride, tetrairon mononitride to be produced less on the surface of a workpiece while securing the hardness of the workpiece after nitriding.;SOLUTION: Disclosed is a gas nitriding device 10 provided with a nitriding section 21 where a mixed gas G of an ammonia gas and a nitrogen gas is made to flow into a heating chamber 12, and the mixed gas G is circulated through the periphery of a workpiece W by a stirring fan 41, thus nitriding the workpiece W. The nitriding section 21 comprises: a temperature increasing part 31 increasing the temperature of the workpiece W; and a soaking part 51 almost uniformly holding the temperature of the workpiece W, and in the respective temperature increasing part 31 and the soaking part 51, the control of the nitriding properties of the workpiece W is performed by controlling the flow velocity of the mixed gas G in the surface of the workpiece W.;COPYRIGHT: (C)2010,JPO&INPIT