BLACK MOLTEN ZINC-ALUMINUM ALLOY PLATING

• Main Authors: URAKAWA YOSHITOMO, TSUNODA HARUHIKO, SUEHIRO ATSUO
• Format: Patent
• Language: English
• Published: 18.10.2012
• Subjects: CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION

PROBLEM TO BE SOLVED: To provide a surface treatment method capable of providing a surface which is more excellent in corrosion resistance and wear resistance and has a darker black color with no unevenness of brightness by blackening treatment compared with that obtained by molten zinc plating, and to produce a product surface-treated by the method.SOLUTION: Firstly, molten zinc-aluminum alloy plating is performed by a one bath method in which a steel material is plated by being immersed in a molten zinc-aluminum alloy, or a two bath method in which the steel material is subjected to molten zinc-aluminum alloy plating after molten zinc plating. Next, blackening treatment is performed. For the blackening treatment, when pale black with high brightness is required, zinc phosphate treatment is performed. When dark black with low brightness is required, the blackening treatment is performed in addition to the zinc phosphate treatment to obtain a desired blackness (brightness).