SURFACE-TREATED STEEL SHEET AND METHOD FOR PRODUCING THE SAME

• Main Authors: YOSHIDA MASAHIRO, SUGANO FUMITAKA, IWANO SUMIHISA, SATO YOHEI, TAIRA SHOICHIRO
• Format: Patent
• Language: English; Japanese
• Published: 19.07.2023
• Subjects: ALLOYS; 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; FERROUS OR NON-FERROUS ALLOYS; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TREATMENT OF ALLOYS OR NON-FERROUS METALS

To provide a surface-treated steel sheet which stably has excellent corrosion resistance and white rust resistance.SOLUTION: In order to achieve the above-described purpose, the present invention provides a surface-treated steel sheet which has a plated coating and a chemical coating formed on the plated coating. The plated coating has a composition that contains 45 to 65 mass% of Al, 1.0 to 4.0 mass% of Si and 1.0 to 10.0 mass% of Mg, with the balance being made up of Zn and unavoidable impurities; a Co content in the unavoidable impurities is 0.080 mass% or less relative to total mass of the plated coating; and diffraction intensities of Si and Mg2Si in the plated coating as determined by X-ray diffraction satisfy a relational expression (1): Si (111)/Mg2Si (111)≤0.8. The chemical coating contains a specific resin and a specific metal compound.SELECTED DRAWING: None 【課題】安定的に優れた耐食性及び耐白錆性を有する表面処理鋼板を提供する。【解決手段】上記目的を達成するべく、本発明は、めっき皮膜と、該めっき皮膜上に形成された化成皮膜と、を備える表面処理鋼板であって、前記めっき皮膜は、Al：45～65質量％、Si：1.0～4.0質量％及びMg：1.0～10.0質量％を含有し、残部がZn及び不可避的不純物からなる組成を有し、前記不可避的不純物中のCo含有量が、前記めっき皮膜の総質量に対して0.080質量％以下であり、前記めっき皮膜中のSi 及びMg2SiのＸ線回折法による回折強度が、以下の関係（１）を満足し、前記化成皮膜は、特定の樹脂及び特定の金属化合物を含有することを特徴とする。Si (111)／Mg2Si (111)≦0.8 ・・・（１）【選択図】なし