A coated iron, a process for the surface treatment of iron or a method for the surface treatment of fastening parts

摘要

[Subject] To provide a fastening part excellent in corrosion resistance and durability and free from hydrogen embrittlement.;[Means] In a surface treatment method for fastening part which comprises undercoating the iron base of a fastening with a zinc duct-contained epoxy resin coating after degreasing and blasting it, and further applying another coating thereon as finish coat, a coating composition containing 20-200 parts by weight of zinc dust and 0.05-0.5 parts by weight of a thermally expanding powder to 10 parts by weight of a vehicle mainly composed of epoxy resin, and 0.2-2.5 parts by weight of an epoxy type silane coupling agent to 100 parts by weight of the zinc powder is used as the zinc dust-contained epoxy resin coating for under coat.