公开(公告)号：EP2617852A4

公开(公告)日：2015-09-16

申请号：EP11825307

申请日：2011-09-15

Applicant: JFE STEEL CORP

Inventor： SAITO HAYATO ,  NAKAJIMA KATSUMI ,  FUNAKAWA YOSHIMASA ,  MORIYASU NORIAKI ,  MURATA TAKAYUKI

IPC: C22C38/00 ,  B32B15/01 ,  C21D6/00 ,  C21D8/02 ,  C21D9/46 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/18 ,  C22C38/24 ,  C22C38/28 ,  C22C38/38

CPC classification number: C21D8/0205 ,  B32B15/013 ,  C21D6/00 ,  C21D8/0226 ,  C21D8/0263 ,  C21D9/46 ,  C21D2211/002 ,  C21D2211/005 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/18 ,  C22C38/24 ,  C22C38/28 ,  C22C38/38

公开(公告)号：EP2604716A4

公开(公告)日：2015-09-02

申请号：EP11816508

申请日：2011-08-09

Applicant: JFE STEEL CORP

Inventor： NAKAJIMA KATSUMI ,  MEGA TETSUYA ,  MIZUNO REIKO ,  MORIYASU NORIAKI

IPC: C22C38/00 ,  B32B15/01 ,  C21D8/02 ,  C21D9/46 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14

CPC classification number: C21D8/005 ,  B32B15/013 ,  C21D8/0226 ,  C21D8/0263 ,  C21D9/46 ,  C21D2211/002 ,  C21D2211/005 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14

公开(公告)号：EP2617851A4

公开(公告)日：2014-04-09

申请号：EP11825306

申请日：2011-09-15

Applicant: JFE STEEL CORP

Inventor： NAKAJIMA KATSUMI ,  SAITO HAYATO ,  FUNAKAWA YOSHIMASA ,  MORIYASU NORIAKI ,  MURATA TAKAYUKI

IPC: C22C38/00 ,  B21B3/00 ,  C21D9/46 ,  C22C38/14 ,  C22C38/58

CPC classification number: C21D8/005 ,  B32B15/013 ,  C21D6/00 ,  C21D8/0226 ,  C21D9/46 ,  C21D2211/002 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/18 ,  C22C38/42 ,  C22C38/44

Abstract: A high strength hot rolled steel sheet having excellent blanking workability is provided. The composition contains C: 0.050 to 0.15%, Si: 0.1 to 1.5%, Mn: 1.0 to 2.0%, P: 0.03% or less, S: 0.0030% or less, Al: 0.01 to 0.08%, Ti: 0.05 to 0.15%, N: 0.005% or less, and the balance being Fe and unavoidable impurities. More than 95% of the microstructure is formed of a bainite phase in terms of area fraction. Average grain diameters of the bainite phase in a region having a thickness equal to 1/4 of the sheet thickness from the surface in the sheet thickness direction is 5 µm or less in an L-direction cross section and 4 µm or less in a C-direction cross section. The number of crystal grains extended in the rolling direction and having an aspect ratio of 5 or more is 7 or less in a sheet thickness center portion. As a result, the strength is increased to a tensile strength TS of 780 MPa or more, the blanked edge forms a fine and uniform ductile fracture surface, and a hot rolled steel sheet having excellent properties at blanked edges and excellent blanking workability is obtained.

公开(公告)号：EP3296415A4

公开(公告)日：2018-03-21

申请号：EP16830039

申请日：2016-07-20

Applicant: JFE STEEL CORP

Inventor： YAMAZAKI KAZUHIKO ,  TOYODA SHUNSUKE ,  MORIYASU NORIAKI ,  IRISA KENTARO

IPC: C22C38/00 ,  C21D8/02 ,  C21D9/46 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/20 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/38 ,  C22C38/40 ,  C22C38/60

CPC classification number: C21D9/46 ,  C21D8/0226 ,  C21D8/0263 ,  C21D2211/001 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/008 ,  C22C38/00 ,  C22C38/001 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/20 ,  C22C38/22 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/32 ,  C22C38/38 ,  C22C38/40 ,  C22C38/60

Abstract: To provide a high-strength hot-rolled steel sheet that has excellent punching workability and hole expandability and has a tensile strength TS of 980 MPa or more; and a method for manufacturing the high-strength hot-rolled steel sheet. The high-strength hot-rolled steel sheet has a chemical composition containing specified amounts of C, Si, Mn, P, S, Al, N, Ti, Cr, and B, and has a microstructure including a bainite phase having an area ratio of 85% or more as a main phase, and a martensite phase or martensite-austenite constituent having an area ratio of 15% or less as a second phase, the balance being a ferrite phase, wherein the second phase has an average grain diameter of 3.0 µm or less, prior-austenite grains have an average aspect ratio of 1.3 or more and 5.0 or less, recrystallized prior-austenite grains have an area ratio of 15% or less relative to non-recrystallized prior-austenite grains, and the high-strength hot-rolled steel sheet contains 0.10% or less by mass% of precipitates having a diameter of less than 20 nm.

公开(公告)号：EP2586885A4

公开(公告)日：2016-08-10

申请号：EP11798291

申请日：2011-06-23

Applicant: JFE STEEL CORP

Inventor： FUNAKAWA YOSHIMASA ,  ARIGA TAMAKO ,  MORIYASU NORIAKI ,  MURATA TAKAYUKI

IPC: C22C38/14 ,  C21D8/02 ,  C21D9/46 ,  C22C38/54

CPC classification number: C21D8/0205 ,  B32B15/013 ,  C21D6/02 ,  C21D8/0226 ,  C21D8/0263 ,  C21D8/0426 ,  C21D8/0463 ,  C21D9/46 ,  C21D9/48 ,  C21D2211/004 ,  C21D2211/005 ,  C22C18/04 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/10 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/22 ,  C22C38/60 ,  C23C2/06 ,  C23C2/285

Abstract: Provided are a high strength hot-rolled steel sheet combining strength with stretch-flange formability and a method for manufacturing the same. The high strength hot-rolled steel sheet has a composition containing more than 0.035% to 0.055% C, 0.2% or less Si, 0.35% or less Mn, 0.03% or less P, 0.03% or less S, 0.1% or less Al, 0.01% or less N, 0.08% to 0.25% Ti, and 0.0005% to 0.0035% B on a mass basis, solute B being 0.0005% or more, the remainder being Fe and unavoidable impurities; a matrix containing a ferrite phase having an area fraction of more than 95%; a microstructure in which Ti carbides having an average grain size of less than 10 nm are finely precipitated in grains of the ferrite phase and the volume fraction of the Ti carbides is 0.0015 to 0.007; a tensile strength of 780 MPa or more; and excellent stretch-flange formability.

公开(公告)号：EP2617850A4

公开(公告)日：2015-08-26

申请号：EP11825305

申请日：2011-09-15

Applicant: JFE STEEL CORP

Inventor： SAITO HAYATO ,  NAKAJIMA KATSUMI ,  FUNAKAWA YOSHIMASA ,  MORIYASU NORIAKI ,  MURATA TAKAYUKI

IPC: C22C38/00 ,  B21B3/00 ,  B32B15/01 ,  C21D6/00 ,  C21D8/02 ,  C21D9/46 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/18 ,  C22C38/58

CPC classification number: C21D8/0226 ,  B21B3/00 ,  B32B15/013 ,  C21D6/00 ,  C21D9/46 ,  C21D2211/002 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/18

公开(公告)号：EP2243851A4

公开(公告)日：2012-04-25

申请号：EP09707458

申请日：2009-02-04

Applicant: JFE STEEL CORP

Inventor： KANEKO SHINJIRO ,  OKUDA KANEHARU ,  SHIMIZU TETSUO ,  MORIYASU NORIAKI ,  WATABE MASAHIDE

IPC: C22C38/00 ,  C21D9/46 ,  C22C38/14

CPC classification number: C22C38/04 ,  C21D1/20 ,  C21D8/0226 ,  C21D8/0263 ,  C21D9/46 ,  C21D2211/002 ,  C21D2211/004 ,  C21D2211/005 ,  C22C38/02 ,  C22C38/06 ,  C22C38/14

公开(公告)号：EP2586886A4

公开(公告)日：2018-01-03

申请号：EP11798295

申请日：2011-06-24

Applicant: JFE STEEL CORP

Inventor： ARIGA TAMAKO ,  NAKAJIMA KATSUMI ,  FUNAKAWA YOSHIMASA ,  MORIYASU NORIAKI ,  MURATA TAKAYUKI

IPC: C22C38/14 ,  C21D8/02 ,  C21D9/46 ,  C22C18/04 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/54 ,  C23C2/06 ,  C23C2/28

CPC classification number: C21D8/0205 ,  B32B15/01 ,  B32B15/013 ,  C21D8/0226 ,  C21D9/46 ,  C21D2211/004 ,  C22C18/04 ,  C22C38/001 ,  C22C38/002 ,  C22C38/004 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/10 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/18 ,  C23C2/06 ,  C23C2/285

Abstract: There is provided a high-strength hot-rolled steel sheet having excellent strength and formability (stretch flange formability) and a method for manufacturing the high-strength hot-rolled steel sheet. The high-strength hot-rolled steel sheet has a composition including C: 0.005% or more and 0.050% or less, Si: 0.2% or less, Mn: 0.8% or less, P: 0.025% or less, S: 0.01% or less, N: 0.01% or less, Al: 0.06% or less, and Ti: 0.05% or more and 0.10% or less, on a mass percent basis, such that S, N, and Ti satisfy Ti ‰¥ 0.04 + (N/14 x 48 + S/32 x 48), the remainder being Fe and incidental impurities; a matrix in which a ferrite phase constitutes 95% by area or more of the entire structure; and a structure in which Ti-containing fine carbide having an average grain size of less than 10 nm is dispersedly precipitated, and the volume ratio of the fine carbide to the entire structure is 0.0007 or more. The high-strength, hot-rolled steel sheet has a tensile strength of 590 MPa or more and excellent formability.

公开(公告)号：EP2617853A4

公开(公告)日：2017-08-16

申请号：EP11825310

申请日：2011-09-15

Applicant: JFE STEEL CORP

Inventor： NAKAJIMA KATSUMI ,  SAITO HAYATO ,  FUNAKAWA YOSHIMASA ,  MORIYASU NORIAKI ,  MURATA TAKAYUKI

IPC: C22C38/00 ,  C21D8/02 ,  C21D9/46 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/18 ,  C22C38/28 ,  C22C38/40 ,  C22C38/58

CPC classification number: C22C38/08 ,  C21D8/0226 ,  C21D8/0263 ,  C21D9/46 ,  C21D2211/002 ,  C22C38/001 ,  C22C38/002 ,  C22C38/005 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/18 ,  C22C38/28 ,  C22C38/40

Abstract: A high strength hot rolled steel sheet having excellent fatigue resistance is provided. A steel having a composition that includes, in terms of mass%, C: 0.05 to 0.15%, Si: 0.2 to 1.2%, Mn: 1.0 to 2.0%, Al: 0.005 to 0.10%, N: 0.006% or less, and at least one selected from Ti: 0.03 to 0.13%, Nb: 0.02 to 0.10%, and V: 0.02 to 0.15% is subjected to rough rolling at a reduction of 80% or more and finish rolling at a finish rolling delivery temperature in the range of 800 to 950°C. Immediately after completion of the finish rolling, the finish rolled sheet is subjected to cooling in two stages including a process of cooling the finish rolled sheet from the finish rolling delivery temperature to a cooling end temperature in the range of 550 to 610°C at an average cooling rate of 25°C/sec. or more and a process of cooling the finish rolled sheet from the cooling end temperature of the previous process to a coiling temperature at an average cooling rate of 100°C/sec. or more. Then the sheet is coiled at 350 to 550°C. In this manner, the microstructure of a surface layer portion having a depth of 500 µm from the surface in the sheet thickness direction comes to contain 50% or more of a fine bainite phase in terms of area fraction and the microstructure of a sheet thickness center portion that extends from a position located at a depth of 1/4 of the sheet thickness to a position located at a depth of 3/4 of the sheet thickness comes to contain 90% or more of a fine bainite phase in terms of area fraction. As a result, a high strength hot rolled steel sheet having a tensile strength TS of 780 MPa or more and excellent fatigue resistance is obtained.

Abstract translation: 提供耐疲劳性优异的高强度热轧钢板。 具有以质量％计含有C：0.05〜0.15％，Si：0.2〜1.2％，Mn：1.0〜2.0％，Al：0.005〜0.10％，N：0.006％以下的组成的钢和 选自Ti：0.03〜0.13％，Nb：0.02〜0.10％，V：0.02〜0.15％中的至少1种，以80％以上的压下率进行粗轧后，在精轧时的精轧温度 范围从800到950°C。 紧接着精轧结束后，精轧后的钢板分两阶段进行冷却，其中包括将精轧后的钢板从精轧出口温度冷却至550〜610℃的冷却结束温度， 平均冷却速度为25°C /秒。 以上，将精轧后的钢板从前一工序的冷却结束温度以100℃/秒的平均冷却速度冷却至卷取温度。 或者更多。 然后片材在350-550℃卷绕。 如此，从板厚方向的表面起500μm的深度的表层部的微细组织以板厚中心的面积率和微细组织的形式含有50％以上的微细贝氏体相 从位于板厚的1/4深度的位置延伸到位于板厚度的3/4深度的位置的部分按照面积分数计含有90％以上的细贝氏体相 。 其结果，得到拉伸强度TS为780MPa以上，耐疲劳性优异的高强度热轧钢板。

公开(公告)号：EP2765211A4

公开(公告)日：2015-11-04

申请号：EP12847962

申请日：2012-11-06

Applicant: JFE STEEL CORP

Inventor： ARIGA TAMAKO ,  FUNAKAWA YOSHIMASA ,  MORIYASU NORIAKI

IPC: B21B1/26 ,  B32B15/01 ,  C21D8/02 ,  C21D8/04 ,  C21D9/46 ,  C22C18/04 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/10 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/60 ,  C23C2/02

CPC classification number: C21D8/0263 ,  B32B15/013 ,  C21D8/0426 ,  C21D8/0463 ,  C21D8/0478 ,  C21D9/46 ,  C21D2211/004 ,  C21D2211/005 ,  C22C18/04 ,  C22C38/00 ,  C22C38/001 ,  C22C38/002 ,  C22C38/008 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/08 ,  C22C38/10 ,  C22C38/12 ,  C22C38/14 ,  C22C38/16 ,  C22C38/24 ,  C22C38/26 ,  C22C38/28 ,  C22C38/60 ,  C23C2/02 ,  Y10T428/12799

Abstract: To provide a high strength hot rolled steel sheet and method for producing the high strength hot rolled steel sheet that has high strength, excellent formability (stretch-flange formability), a tensile strength of 780 MPa or more, and excellent material uniformity. The hot rolled steel sheet has the composition comprising : C: 0.03% or more to less than 0.07%; Si: 0.3% or less; Mn: 0.5% or more to 2.0% or less; P: 0.025% or less; S: 0.005% or less; N: 0.0060% or less; Al: 0.1% or less; Ti: 0.07% or more to 0.11% or less; and V: 0.08% or more to less than 0.15% on a mass percent basis, such that Ti and V contents satisfy the following formula: 0.18 ‰¤ Ti + V ‰¤ 0.24 (where Ti and V are respective contents of the elements (by mass%)). Balance comprises Fe and inevitable impurities. A matrix has an area ratio of 95% or more with respect to an overall structure of a ferrite phase. In the structure, fine carbide is dispersedly precipitated, the fine carbide containing Ti and V has an average particle size of less than 10 nm in the matrix, and a volume fraction of the fine carbide is 0.0020 or more with respect to an overall structure.

Abstract translation: 一种用于制造高强度热轧钢板提供一种高强度热轧钢板和方法做了具有高强度，优良的加工性（延伸凸缘性），780MPa以上的拉伸强度，以及优异的材料的均匀性。 该热轧钢板具有组合物，包含：C：0.03％以上在小于0.07％; 的Si：0.3％以下; 的Mn：0.5％以上至2.0％以下; P：0.025％或更少; S：0.005％或更少; N：0.0060％以下; 的Al：0.1％以下; 钛：0.07％以上且0.11％，或更小; 及V：0.08％以上且小于0.15％，以质量％计，谋求确实Ti和V含量满足以下公式：12点18‰¤的Ti + V‰¤12点24（其中，Ti和V为各元素的respectivement内容（ 以质量％计））。 其余部分包含Fe和不可避免的杂质。 甲基质具有或95％面积比以上，相对于在铁素体相的总体结构。 在该结构中，微细碳化物是分散析出，微细碳化物包含Ti和V具有在基质小于10nm的平均颗粒尺寸，并且微细碳化物的体积分数为0.0020或更与整体结构相对于。