Ion-nitriding process

摘要

The present invention provides an ion-nitriding process wherein a workpiece having at least one aperture is subjected to a DC voltage in an atmosphere of nitrogen-containing gas, characterized in that a first nitriding step is carried out under a vacuum which is strong enough to suppress arc discharge on the workpiece, and a second nitriding step is carried out under a weaker vacuum as compared to that in the first step so that glow discharge is produced even in the aperture of the workpiece.