Hot rolled steel sheet and method for the same

• Main Authors: YI IL CHEOL, NA HYUN TAEK, LEE JE WOONG, KIM SUNG IL
• Format: Patent
• Language: English; Korean
• Published: 28.06.2024
• Subjects: ALLOYS; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKINGWITHOUT ESSENTIALLY REMOVING MATERIAL; CHEMICAL SURFACE TREATMENT; CHEMISTRY; CLEANING OR DEGREASING OF METALLIC MATERIAL BY CHEMICALMETHODS OTHER THAN ELECTROLYSIS; 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; MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES OR PROFILES,OTHERWISE THAN BY ROLLING; MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVINGMATERIAL; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; PERFORMING OPERATIONS; PUNCHING METAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TRANSPORTING; TREATMENT OF ALLOYS OR NON-FERROUS METALS

열연강판 및 그 제조방법이 제공된다. 본 발명의 열연강판은, 중량%로, C:0.02∼0.08%, Si:0.01∼0.5%, Mn:0.8∼1.8%, Al:0.01∼0.1%, P:0.001∼0.02%, S:0.001∼0.01%, N:0.001∼0.01%, Ti: 0.01~0.12%, Nb:0.01~0.05%, 잔부 Fe 및 불가피한 불순물을 포함하고, 관계식 1에 의해 정의되는 X값이 3.5~6.0을 만족하며, 페라이트와 베이나이트 상의 합: 90면적% 이상 그리고 잔여 마르텐사이트 및 MA상의 합: 10면적% 미만을 포함하는 미세조직을 가진다. A hot-rolled steel sheet and a manufacturing method therefor are provided. The hot-rolled steel sheet of the present invention includes, by wt%, 0.020-0.080% of C, 0.01-0.50% of Si, 0.8-1.8% of Mn, 0.010-0.100% of Al, 0.001-0.020% of P, 0.001-0.010% of S, 0.001-0.010% of N, 0.010-0.120% of Ti, 0.010-0.050% of Nb, and the remainder of Fe and inevitable impurities, satisfies an X value of 3.50-6.00 as defined by equation 1, and has a micro-structure in which the sum of ferrite and bainite phases is at least 90 area% and the sum of the remaining martensite and MA phases is less than 10 area%.