| 摘要 |
PURPOSE:To form an undercoat excellent in rust-proofing property without the use of forming film treatment by the procedure in which a nitride layer is formed on the surface of an iron steel part by a pure nitriding method or a soft nitriding method as an undercoat treatment. CONSTITUTION:A pure nitride layer is formed on the surface of an iron steel part by a pure nitriding method using a salt bath, gas, etc., or a soft nitride layer is formed on the surface by a soft nitriding method using a salt, gas, ion, etc. The nitride layer is excellent in rust-proofing property and also enables a paint film excellent in adhesiveness to be formed on the nitride layer by direct coating of a paint. This method is different from the conventional forming film treatment method in that undercoat of excellent rust-proofing property can be obtained regardless of the shape and thickness of parts and also regardless of the edge, end, flaws, etc., of parts to be coated. |
