发明申请
- 专利标题: HIGH TENSILE STRENGTH HOT-ROLLED STEEL SHEET HAVING SUPERIOR STRAIN AGING HARDENABILITY AND METHOD FOR PRODUCING THE SAME
- 专利标题(中): 具有超级应变老化的高拉伸强度热轧钢板及其制造方法
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申请号: US12367577申请日: 2009-02-09
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公开(公告)号: US20090202384A1公开(公告)日: 2009-08-13
- 发明人: Akio Tosaka , Sinjiro Kaneko , Yoichi Tominaga , Noriyuki Katayama , Nobutaka Kurosawa , Kei Sakata , Osamu Furukimi
- 申请人: Akio Tosaka , Sinjiro Kaneko , Yoichi Tominaga , Noriyuki Katayama , Nobutaka Kurosawa , Kei Sakata , Osamu Furukimi
- 申请人地址: JP Tokyo
- 专利权人: JFE Steel Corporation, a Corporation of Japan
- 当前专利权人: JFE Steel Corporation, a Corporation of Japan
- 当前专利权人地址: JP Tokyo
- 优先权: JPJP2000-046335 20000223; JPJP2000-053439 20000229; JPJP2000-156272 20000526
- 主分类号: C22C38/00
- IPC分类号: C22C38/00 ; C22C38/16 ; C22C38/18 ; C22C38/08 ; C22C38/14 ; C22C38/12
摘要:
A high tensile strength hot-rolled steel sheet having superior strain aging hardenability, which has high formability and stable quality characteristics, and in which satisfactory strength is obtained when the steel sheet is formed into automotive components, thus enabling the reduction in weight of automobile bodies. Specifically, a method for producing a high tensile strength hot-rolled steel sheet having superior strain aging hardenability with a BH of 80 MPa or more, a ΔTS of 40 MPa or more, and a tensile strength of 440 MPa or more includes the steps of heating a steel slab to 1,000° C. or more, the steel slab containing, in percent by mass, 0.15% or less of C, 0.45% or less of Si, 3.0% or less of Mn, 0.08% or less of P, 0.02% or less of S, 0.02% or less of Al, 0.0050% to 0.0250% of N, and optionally 0.1% or less in total of at least one of more than 0.02% to 0.1% of Nb and more than 0.02% to 0.1% of V, the ratio N (mass %)/Al (mass %) being 0.86 or more; rough-rolling the steel slab to form a sheet bar; finish-rolling the sheet bar at a finishing temperature of 800° C. or more; cooling at a cooling rate of 20° C. to 40° C./s or more within 0.5 second after the finish-rolling; and coiling at a temperature of 650° C. to 450° C. or less.