초 고강도 다중상 강철 및 그로부터 냉간 압연 강 스트립을 제조하는 방법

• Main Authors: KLUGE SASCHA, MEYER CHRISTIAN, MATTHIES PETER, SCHULZ THOMAS
• Format: Patent
• Language: Korean
• Published: 09.03.2018
• Subjects: ALLOYS; CHEMISTRY; FERROUS OR NON-FERROUS ALLOYS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

본 발명은 듀얼 상 미세구조 또는 복합 상 미세구조를 가지고, 특히 청구항 1의 전문에 따른 경량의 차량 구조를 위한 생산 및 가공에 대한 개선된 특성을 갖는 잔류 오스테나이트의 적은 비율을 갖는 초 고강도 다중상 강철에 관한 것이다. 본 발명의 교시에 따르면, 이 목적은 wt.%로 특정한 내용물을 갖는 980 MPa의 최소 인장 강도를 갖는 초 고강도 다중-상 강철에 의해 달성된다. The invention relates to an ultrahigh strength multiphase steel with a dual-phase microstructure or a complex-phase microstructure and with a low content of residual austenite in particular for lightweight vehicle construction, to a method for producing cold-rolled steel strips from such a steel, and to steel strips produced using said method. The aim of the invention is a novel alloy concept with which the processing window for the continuous annealing of cold strips can be extended. According to the invention, this is achieved by a multiphase steel with a minimum tensile strength of 980 MPa containing (contents in wt. %): C≥0.075 to ≤0.115, Si≥0.400 to ≤0.500, Mn≥1.900 to ≤2.350, Cr≥0.250 to ≤0.400, Al≥0.005 to ≤0.060, N≥0.0020 to ≤0.0120, S≤0.0020, Nb≥0.005 to ≤0.060, Ti≥0.005 to ≤0.060, B>0.0005 to ≤0.0010, Mo>0.200 to ≤0.300, Ca>0.0010 to ≤0.0060, Cu≤0.050, Ni≤0.050, and residual iron, including customary steel-accompanying smelting-related impurities, wherein the total content of Mn+Si+Cr is ≥2.500 to ≤3.250 with a view to a processing window which is as wide as possible during the annealing process, in particular during the continuous annealing process, of cold strips of said steel.