| 摘要 |
PURPOSE:To produce nitrided cast iron parts having high resistance to corrosion, particularly high resistance to corrosive wear, by grinding the surface of a cast iron blank material after nitriding and coating and rubbing a resin incorporated therein with a sacrificial corrososive metal on said surface then subjecting the material to a heat treatment. CONSTITUTION:The surface of a cast iron blank material 14 is subjected to soft nitriding to form a nitrogenous compd. layer 10 on the surface and said layer is hardened. Then the parts 12 of graphite which is the compsn. of the material 14 build up. Clearances are generated between the graphite 12 and the base material 14 around said graphite owing to thinning of the graphite. The build- ups on the surface are honed to a smooth surface. A resin contg. a specific ratio of a sacrificial corrosive metal, for example, an epoxy resin is coated on the surface and after the resin layer 15 is dried, the layer is subjected to rubbing with a rubber grindstone and is subjected to a heat treatment in the atmospheric air. Then the exposed parts of the graphite are sealed by the resin parts 16. |
