公开(公告)号：US20190226067A1

公开(公告)日：2019-07-25

申请号：US16326784

申请日：2017-08-29

申请人： JFE STEEL CORPORATION

发明人： Hidekazu MINAMI ,  Shinjiro KANEKO ,  Reiko SUGIHARA ,  Kazunori TAHARA ,  Kazuma MORI

IPC分类号： C22C38/60 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/00 ,  C22C38/02 ,  C22C38/04 ,  C22C38/06 ,  C22C38/34 ,  C22C38/36 ,  C23C2/06 ,  C23C2/40 ,  C21D8/02 ,  C21D9/46

摘要： A high-strength steel sheet having a TS of 780 MPa or more, excellent stretch flangeability, and excellent in-plane anisotropy of TS is provided. A high-strength steel sheet comprises: a predetermined chemical composition; a steel microstructure including, in area fraction, ferrite: 20% or more and 50% or less, lower bainite: 5% or more and 40% or less, martensite: 1% or more and 20% or less, and tempered martensite: 20% or less, and including, in volume fraction, retained austenite: 5% or more, the retained austenite having an average grain size of 2 μm or less; and a texture having an inverse intensity ratio of γ-fiber to α-fiber of 3.0 or less.