| 摘要 |
PURPOSE: To perfectly dissolve away molten salt on the object to be treated by hot water rinsing in a cleaning stage even as for a part with a complicated shape by performing displacement washing in a salt bath having a specified composition after salt bath nitriding treatment, and to further improve the level of its corrosion resistance by the displacement washing with the salt bath having a specified composition. CONSTITUTION: A metallic member is dipped into a salt bath comprising Li¬+, Na¬+ and K¬+ as cation components and CNO¬- and CO3¬-- as anion components to form a nitride layer on the surface thereof. In the method where alkali hydroxide, combined water, free water, moist air or the like are added to or impregnated into a salt bath to strengthen the oxidizing power of the salt bath, so that a nitride layer is formed on the surface of a metallic member, and simultaneously, an oxide layer is formed on the outermost surface thereof, the metallic member is dipped into a salt bath comprising alkali nitrate in the stage subsequently to the nitriding salt bath treatment. |
