HIGH STRENGTH HOT-DIP GALVANIZED STEEL SHEET HAVING EXCEELENT COATING ADHESION AND WELDABILITY AND METHOD OF MANUFACTURING THE SAME

• Main Authors: MIN KWANG TAI, KIM YOUNG HA, KANG KI CHEOL, KIM MYUNG SOO
• Format: Patent
• Language: English; Korean
• Published: 29.11.2022
• 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

One embodiment of the present invention provides a high-strength hot-dip galvanized steel sheet with excellent plating adhesion and weldability and a manufacturing method thereof. In the hot-dip galvanized steel sheet having a base steel sheet and a hot-dip galvanized layer formed on one or both surfaces of the base steel sheet, the base steel sheet includes carbon (C): 0.1 to 0.3%, silicon (Si): 0.1 to 2.0%, aluminum (Al): 0.1 to 1.5%, manganese (Mn): 1.5 to 3.0%, balance Fe, and unavoidable impurities in weight percent. The sum of Si and Al satisfies 1.2 to 3.5%. The ratio of Al and Si (Al/Si) satisfies 0.5 to 2.0. An internal oxide layer having a thickness of 1 to 5 μm directly below the surface of the base steel sheet. The decarburization rate in the region from directly below the surface of the base steel sheet to 50 μm is 50% or more. 본 발명의 일 실시형태는 소지강판 및 상기 소지강판의 일면 또는 양면에 형성되는 용융아연도금층을 갖는 용융아연도금강판으로서, 상기 소지강판은 중량%로, 탄소(C): 0.1~0.3%, 실리콘(Si): 0.1~2.0%, 알루미늄(Al): 0.1~1.5%, 망간(Mn): 1.5~3.0%, 잔부 Fe 및 불가피한 불순물을 포함하고, 상기 Si 및 Al의 합은 1.2~3.5%를 만족하며, 상기 Al 및 Si의 비(Al/Si)는 0.5~2.0을 만족하고, 상기 소지강판의 표면 직하에 두께가 1~5㎛인 내부산화층을 포함하며, 상기 소지강판의 표면 직하로부터 50㎛까지의 영역에서의 탈탄율이 50% 이상인 도금밀착성 및 용접성이 우수한 고강도 용융아연도금강판 및 그 제조방법을 제공한다.