고강도 강 제품 및 그 제조 방법

• Main Authors: LIIMATAINEN TOMMI, KESTI VILI, LIND MARTIN, SUIKKANEN PASI, PYYKKOENEN JUHA, HEMMILAE MIKKO, NYMANN ERIK, NILSSON ROBIN
• Format: Patent
• Language: Korean
• Published: 24.02.2023
• Subjects: ALLOYS; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKINGWITHOUT ESSENTIALLY REMOVING MATERIAL; 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; 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

열간-압연된 스트립 강 제품으로서, 중량 백분율(중량%)로: 0.025% 내지 0.070% C, 0% 내지 1.10% Si, 0.50% 내지 2.0% Mn, <0.020% P, <0.050% S,<0.010% N, 0% 내지 0.60% Cr, 0% 내지 0.20% Ni, 0% 내지 0.25% Cu, 0% 내지 0.20% Mo, 0% 내지 0.15% Al, 0% 내지 0.050% Nb, 0.020% 내지 0.20 내지 % V, 0.020% 내지 0.15% Ti, 0% 내지 0.0010% B, 나머지 Fe 및 불가피한 불순물로 구성되는 화학적 조성을 가지며, 스트립 강 제품은, 부피 백분율(부피%)로, 90 이상, 바람직하게 95이상, 더 바람직하게 98 이상의 페라이트를 포함하는 미세조직을 갖고, 페라이트 조직은 10% 내지 50%의 준-다각형 페라이트를 포함하고, 페라이트 조직의 나머지는 다각형 페라이트 및/또는 베이나이트이며; 그리고 강 스트립 제품은 10 ㎛ 미만의 평균 페라이트 입자 크기, 50% 이상의 평균 홀 팽창비, 660 MPa 이상의 압연 방향에 대한 길이방향의 항복 강도(Rp0.2%) 및 760 MPa 이상의 인장 강도를 갖는다. A hot-rolled strip steel product having a chemical composition consisting of, in terms of weight percentages (wt. %): 0.025%-0.070% C, 0%-1.10% Si, 0.50%-2.0% Mn, <0.020% P, <0.050% S,<0.010% N, 0%-0.60% Cr, 0%-0.20% Ni, 0%-0.25% Cu, 0%-0.20% Mo, 0%-0.15% Al, 0%-0.050% Nb, 0.020%-0.20- % V, 0.020%-0.15% Ti, 0%-0.0010% B, remainder Fe and inevitable impurities, wherein the strip steel product has a microstructure comprising of, in terms of volume percentages (vol. %), ferrite ≥90%, preferably ≥95%, more preferably ≥98%, wherein the ferrite structure comprises 10%-50% quasi-polygonal ferrite and a reminder of ferrite structure is polygonal ferrite and/or bainite: and wherein the steel strip product has an average ferrite grain size of <10µm, an average hole expansion ratio of ≥50%,a yield strength (Rp0.2%) longitudinal to rolling direction of ≥660 MPa and a tensile strength of ≥760 MPa.