发明名称 |
Composite structure cold-rolled sheet steel with excellent elongation and stretch flange formability |
摘要 |
The present invention provides a TRIP-type composite structure steel plate of the TPF steel type in which elongation and stretch flange formability at room temperature are improved by controlling the morphology of the second-phase structure. In a composite structure sheet steel comprising 0.02 to 0.12% C, 0.5 to 2.0% Si+A1 and 1.0 to 2.0% Mn, with the remainder being Fe and unavoidable impurities, and comprising 80% or more polygonal ferrite (steel structure space factor) and 1 to 7% retained austenite, with the remainder being bainite and/or martensite, wherein the elongation and stretch flange formability of the composite sheet steel are improved by reducing the number of bulky, massive second phases with an aspect ratio of 1:3 or less and a mean grain size of 0.5 µm or more in the second phase of this composite structure, which comprises retained austenite and martensite. |
申请公布号 |
EP1674586(A1) |
申请公布日期 |
2006.06.28 |
申请号 |
EP20050026756 |
申请日期 |
2005.12.07 |
申请人 |
KABUSHIKI KAISHA KOBE SEIKO SHO;SHINSHU TLO CO. LTD. |
发明人 |
IKEDA, SHUSHI;SUGIMOTO, KOICHI;AKAMIZU, HIROSHI;MUKAI, YOICHI |
分类号 |
C22C1/06;C21D8/02;C21D9/46;C22C38/02;C22C38/04 |
主分类号 |
C22C1/06 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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