FORMATION OF COATING FILM EXCELLENT IN WEAR RESISTANCE AND IRON-BASE MATERIAL COATED WITH WEAR RESISTANT COATING FILM

摘要

PROBLEM TO BE SOLVED: To form a coating film excellent in wear resistance on the surface of an iron-base member by electrodepositing oxide-contg. iron sulfide on the member as the cathode with an alkaline electrolytic soln. of a specified pH contg. trivalent iron ions, a chelating agent for the iron ions and a sulfur compd. ;SOLUTION: Electrolysis is carried out using an iron-base member as the cathode at 0.3-12 A/dm² current density in an alkaline electrolytic soln. of ≥pH 9 contg. 0.05-0.5 mol/l trivalent iron ions, 0.1-2.0 mol.% 1st water-soluble chelating agent for the iron ions in a molar ratio of ≥2 to the iron ions and 0.005-1.0 mol/l, sulfur compd. in a molar ratio of 1:10 to 10:20 to the iron ions or further contg. 0.001-1.0 mol/l sulfite in a molar ratio of 1:5 to 1:1 to the sulfur compd., a prescribed amt. of NH₃ and a 2nd chelating agent for divalent iron ions having an NO₂ group. An oxide-contg. iron sulfide-base coating film excellent in wear resistance is electrodeposited on the cathode.;COPYRIGHT: (C)1999,JPO