发明名称 |
High-strength cold-rolled steel sheet having outstanding elongation and superior stretch flange formability and method for production thereof |
摘要 |
A high-strength cold-rolled steel sheet is disclosed that comprises a steel including C: 0.05 to 0.13 mass %, Si: 0.5 to 2.5 mass %, and Mn: 0.5 to 3.5 mass %, as well as Mo: 0.05 to 0.6 mass % and/or Cr: 0.05 to 1.0 mass %. The steel sheet is of composite structure of a ferrite+a second phase wherein the second phase has an area rate of 30 to 70% and is combined approximately in a shape of a network; a circle-equivalent average ferrite grain size is not more than 10 mum; and a circle-equivalent diameter of ferrite grain aggregate that exists continuously in an area surrounded by the second phase is not more than 3 times of the average ferrite grain size. The steel sheet has a high-strength and satisfies a balance of elongation and stretch flange formability (ratio of hole expansion) at a higher level.
|
申请公布号 |
US2005167007(A1) |
申请公布日期 |
2005.08.04 |
申请号 |
US20050045309 |
申请日期 |
2005.01.31 |
申请人 |
KABUSHIKI KAISHA KOBE SEIKO SHO (KOBE STEEL, LTD.) |
发明人 |
MIURA MASAAKI;MUKAI YOICHI;OMIYA YOSHINOBU;KOZUMA SHINJI |
分类号 |
C21D9/46;C22C38/00;C22C38/18;C22C38/38;(IPC1-7):C22C38/18 |
主分类号 |
C21D9/46 |
代理机构 |
|
代理人 |
|
主权项 |
|
地址 |
|