Abstract: A nitriding method includes the steps of nitriding an object held under a nitriding gas atmosphere in a sealed furnace and applying vibration energy to one or both of the nitriding gas and the object W to facilitate nitriding. A nitriding apparatus includes a nitriding furnace for holding an object W to be nitrided in a sealed manner, means 30 for supplying a nitriding gas to the furnace, and means 2 for applying vibration to the atmosphere gas in the furnace 1 to faciliate nitriding. According to the method or apparatus, nitriding-resistant or complex-shaped materials can be nitrided at high efficiency and a nitrided layer can be formed at a lower temperature for a shorter time as compared with conventional processes.

Abstract: A composite diffusion type nitriding method and a composite diffusion type nitriding apparatus of the present invention are effectively used for nitriding various materials, such as machine parts, as well as a material which is difficult for nitriding by a conventional method. The composite diffusion nitriding apparatus is formed of a container filled with solid granular materials, a furnace for housing the container therein, a nitriding gas introduction path for introducing the nitriding gas into the container, and an exhausting path for exhausting the gas from the container. In the method, the material to be nitrided is placed in the solid granular materials, and the nitriding gas is supplied to flow through the solid granular materials to thereby nitride the material.