PRODUCING METHOD FOR HIGH-STRENGTH GALVANIZED STEEL PLATE, AND PRODUCING METHOD FOR HIGH-STRENGTH ALLOY MOLTEN GALVANIZED STEEL PLATE

• Main Authors: SUZUKI YOSHITSUGU, NAGATAKI YASUNOBU, MIYATA MAI
• Format: Patent
• Language: English; Japanese
• Published: 18.02.2016
• 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; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TREATMENT OF ALLOYS OR NON-FERROUS METALS

PROBLEM TO BE SOLVED: To provide a producing method for producing a high-strength galvanized steel plate excellent in a plating adhesion and a surface appearance, while suppressing a problem to be caused by an oxide to be formed on a steel plate surface containing Cr, and a producing method for producing a high-strength alloy molten galvanized steel plate.SOLUTION: A high-strength galvanized steel plate is manufactured by a method comprising: a first heating step of holding a steel plate of a specific component composition in a specific Hconcentration, in a specific dew-point atmosphere, at a specific temperature and for a specific time period; a cooling step of cooling the steel plate after the first heating step; an electrolytic treatment step of performing electrolytic treatment on the steel plate after the cooling step, under a specific condition; a second heating step of holding the steel plate after the electrolytic treatment, in a predetermined Hconcentration, in a predetermined dew-point atmosphere and at a predetermined temperature for a predetermined time period; and a plating treatment step of subjecting the steel plate after the second heating step, to a molten zinc plating treatment.SELECTED DRAWING: None 【課題】Ｃｒを含有する鋼板について、鋼板表面に形成される酸化物が原因となる問題を抑え、めっき密着性、表面外観に優れた高強度溶融亜鉛めっき鋼板を製造するための製造方法、及び高強度合金化溶融亜鉛めっき鋼板を製造するため製造方法を提供する。【解決手段】特定の成分組成鋼板を、特定のＨ２濃度、特定の露点雰囲気中、特定の温度で特定の時間保持する第１加熱工程と、第１加熱工程後の鋼板を、冷却する冷却工程と、冷却工程後の鋼板を特定の条件で、電解処理する電解処理工程と、電解処理工程後の鋼板を、特定のＨ２濃度、特定の露点雰囲気中、特定の温度で特定の時間保持する第２加熱工程と、第２加熱工程後の鋼板に、溶融亜鉛めっき処理を施すめっき処理工程とを、備える方法で高強度溶融亜鉛めっき鋼板を製造する。【選択図】なし