FORMATION METHOD OF PROTECTIVE FILM, AND HIGH CORROSION RESISTANCE STEEL MEMBER HAVING PROTECTIVE FILM

• Main Authors: MORI EIJI, ABE MASATAKE, FUJIMOTO SACHIKO
• Format: Patent
• Language: English; Japanese
• Published: 08.02.2018
• 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 formation method of a protective film having high corrosion resistance under strong alkaline and neutral environments; and to provide a high corrosion resistance steel member having the protective film.SOLUTION: A formation method of a protective film includes steps of: plating the surface of a steel member in an alloy bath containing zinc and aluminium to form a zinc-aluminum alloy layer; and immersing the steel member on which the zinc-aluminum alloy layer is formed into a phosphate solution, to thereby form a zinc phosphate coating sheet.SELECTED DRAWING: None 【課題】強アルカリ性及び中性環境下において耐食性が高い保護膜の形成方法及び保護膜を有する高耐食性鋼部材を提供する。【解決手段】鋼部材の表面を亜鉛及びアルミニウムを含む合金浴中でめっきして亜鉛アルミ合金層を形成する工程と、前記亜鉛アルミ合金層が形成された鋼部材をリン酸塩溶液に浸漬してリン酸亜鉛被膜を形成する工程とを含む保護膜の形成方法である。【選択図】なし