公开(公告)号：US20170136512A1

公开(公告)日：2017-05-18

申请号：US15321071

申请日：2015-06-17

申请人： NIPPON STEEL & SUMITOMO METAL CORPORATION

发明人： Yoshihiro SERIZAWA ,  Shinsuke KAI

IPC分类号： B21B45/02

CPC分类号： B21B45/0281 ,  B21B45/0218

摘要： A plurality of water removing nozzles of a water removing apparatus comprise one or more of a single far water removing nozzle and a far water removing nozzle group. The single far water removing nozzle forms a far end water removal single area that does not include one end but includes the other end in the width direction of a steel sheet conveyance plane. The far water removing nozzle group forms the far end water removal single area and one or more inner water removal single areas that do not include either end in the width direction of the steel sheet conveyance plane, in such a manner that the far end water removal single area and the one or more inner water removal single areas are aligned in order from the one end side to the other end side while overlapping with each other in the width direction of the steel sheet conveyance plane and aligned in order from the upstream side to the downstream side without overlapping in the conveyance direction.

公开(公告)号：US20190177822A1

公开(公告)日：2019-06-13

申请号：US16325574

申请日：2016-08-18

申请人： NIPPON STEEL & SUMITOMO METAL CORPORATION

发明人： Daisuke MAEDA ,  Hiroshi SHUTO ,  Kazuya OOTSUKA ,  Akifumi SAKAKIBARA ,  Shinsuke KAI

IPC分类号： C22C38/28 ,  C22C38/22 ,  C22C38/16 ,  C22C38/14 ,  C22C38/12 ,  C22C38/08 ,  C22C38/06 ,  C22C38/04 ,  C22C38/02 ,  C22C38/00 ,  C21D9/46 ,  C21D8/02

摘要： A hot-rolled steel sheet includes, by mass %, C: 0.030% or more and less than 0.075%, Si+Al: 0.08% to 0.40%, Mn: 0.5% to 2.0%, and Ti: 0.020% to 0.150%, and includes a microstructure having a ferrite and a martensite. The hot-rolled steel sheet includes a microstructure having, by area %, 90% to 98% of the ferrite, 2% to 10% of the martensite. 0% to 3% of a bainite, and 0% to 3% of a pearlite. In the martensite, the number proportion of martensite grains having a hardness of 10.0 GPa or more is 10% or less, and a ratio N1/N2 of the number N1 of martensite grains having a hardness of 8.0 GPa or more and less than 10.0 GPa to the number N2 of martensite grains having a hardness of less than 8.0 GPa is 0.8 to 1.2.