Patent attributes
The present nitriding-oxidizing method for a metal member is imposed, which includes providing a powdery nitriding agent comprised of a powdery nitride compound and inorganic powder, wherein the powdery nitride compound decomposes below a nitriding-oxidizing temperature to generate nitriding gas, and the inorganic powder does not react; embedding an essential part of the metal member to be nitrided and oxidized into the powdery nitriding agent, and then performing nitridization-oxidization while an oxygen-containing gas is always present in the powdery nitriding agent; and, if necessary, allowing the metal member after nitridization-oxidization to carry out a reoxidization in an oxygen-containing atmosphere. The method of the present invention has a broader temperature range for nitridization-oxidization.
