Abstract: This invention relates to a retort type apparatus for ion-nitriding treatment which is so designed as to effect heating and nitriding of a workpiece at high thermal efficiency, with excellent uniformity and in a short time, by using both glow discharge and heat produced by a heating element.

Abstract: This invention relates to a retort type apparatus for ion-nitriding treatment which is so designed as to effect heating and nitriding of a workpiece at high thermal efficiency, with excellent uniformity and in a short time, by using both glow discharge and heat produced by a heating element.

Abstract: Disclosed is an improved ion-nitriding process comprising ion-nitriding a workpiece at a high voltage level of glow discharge in a gas atmosphere resulting from the introduction of a gas mixture containing a specific amount of ammonia into a nitriding reactor, and then, further ion-nitriding the same workpiece at a lower voltage level of glow discharge in a gas atmosphere resulting from the introduction of a gas mixture not containing ammonia into the reactor.

Abstract: An ion-nitriding process in which workpieces are subjected to a two-step glow discharge in a nitrogen and hydrogen atmosphere, there being a larger nitrogen to hydrogen ratio in the second step.

Abstract: 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.

Abstract: An ion-nitriding apparatus wherein heating and nitriding of workpieces can be carried out at high thermal efficiency, with excellent uniformity and in a short time by the combined use of glow discharge and heat generated by a heat-producing element. Heating efficiency can be raised in heating of workpieces by lessening the heat value to be released out of the furnace, and overheating of workpieces can be prevented in nitriding of them by increasing the heat value to be released out of the furnace in proportion to the increase of glow discharge output, and thus the nitriding efficiency can be raised.

Abstract: An ion-nitriding apparatus which is designed so that in heating and nitriding a workpiece by the combined use of glow discharge and heat generated by a heat-producing element, uniform temperature distribution of the workpiece during glow discharge can be obtained, thereby preventing overheating of the workpiece and realizing uniform heating and uniform nitriding of the workpiece.

Abstract: This invention relates to an apparatus for continuous glow discharge nitriding treatment whereby a workpiece is treated while it is being transferred in a vacuum chamber. It comprises a heating means to heat the workpiece up to the suitable temperature at which glow discharge nitriding is going on steadily, a heat-retaining means to keep the heated workpiece at said temperature and a discharge means to carry out discharge nitriding by glow discharge.