Method for nitriding-processing iron group series alloy substrate

摘要

A processing method for nitriding an iron group series alloy substrate, or processing subject, containing an alloy element for forming nitride by plasma nitriding treatment including a passivated membrane removing treatment step. The passivated membrane removing treatment is performed by hydrogen sputtering under reduced pressure. It is desirable that this hydrogen sputtering is initiated from a normal temperature in a process of raising a temperature of a processing subject for plasma nitriding.