公开(公告)号：US5017248A

公开(公告)日：1991-05-21

申请号：US442445

申请日：1989-11-27

申请人： Osamu Kawano ,  Manabu Takahashi ,  Junichi Wakita ,  Kazuyoshi Esaka

发明人： Osamu Kawano ,  Manabu Takahashi ,  Junichi Wakita ,  Kazuyoshi Esaka

IPC分类号： C21D1/19 ,  C21D8/02 ,  C22C38/00

CPC分类号： C21D1/19 ,  C21D8/0226 ,  C22C38/002 ,  C21D2211/001 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/008 ,  C21D8/0263

摘要： A hot rolled steel sheet with a high strength and a distinguished formability, and a process for producing the same are disclosed. The steel sheet comprises 0.15 to 0.4% by weight of C, 0.5 to 2.0% by weight of Si, and 0.5 to 2.0% by weight of Mn, the balance being iron and inevitable impurities, and has a microstructure composed of ferrite, bainite and retained austenite phases with the ferrite phase being in a ratio (V.sub.PF /d.sub.PF) of polygonal ferrite volume fraction V.sub.PF (%) to polygonal ferrite average grain size d.sub.PF (.mu.m) of 7 or more and the retained austenite phase being contained in an amount of 5% by volume or more on the basis of the total phases. The steel sheet can be produced with a high productiviity and without requiring special alloy elements.

公开(公告)号：USD276909S

公开(公告)日：1984-12-25

申请号：US396006

申请日：1982-07-07

申请人： Manabu Takahashi ,  Toshihiko Kadota

设计人： Manabu Takahashi ,  Toshihiko Kadota