公开(公告)号：EP1951519A2

公开(公告)日：2008-08-06

申请号：EP06846104.5

申请日：2006-10-17

申请人： ExxonMobil Upstream Research Company ,  Nippon Steel Corporation

发明人： BANGARU, Narasimha-rao, V. ,  KOO, Ja-young ,  JIN, Hyun-Woo ,  OZEKCIN, Adnan ,  FAIRCHILD, Douglas, P. ,  TERADA, Yoshio ,  ASAHI, Hitoshi ,  HARA, Takuya ,  SUGIYAMA, Masaaki

IPC分类号： B32B15/01

CPC分类号： C22C38/44 ,  B32B15/01 ,  C21D1/18 ,  C21D1/19 ,  C21D6/005 ,  C21D8/02 ,  C21D8/021 ,  C21D2211/002 ,  C21D2211/005 ,  C21D2211/008 ,  C22C38/08 ,  C22C38/12 ,  C22C38/14 ,  C22C38/58

摘要： A dual phase, high strength steel having a composite microstructure of soft and hard phases providing a low yield ratio, high strain capacity, superior weldability, and high toughness is provided. The dual phase steel includes from, about 10% by volume to about 60% by volume of a first phase or constituent consisting essentially of fine-grained ferrite. The first phase has a ferrite mean grain size of about 5 microns or less. The dual phase steel further includes from about 40% by volume to about 90% by volume of a second phase or constituent comprising fine-grained martensite, fine-grained lower bainite, fine-grained granular bainite, fine-grained degenerate upper bainite, or any mixture thereof. Methods for making the same are also provided.