| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a high-strength steel sheet excellent in deep drawability, and a method of manufacturing the same. <P>SOLUTION: The composition of this high-strength steel sheet includes 0.010% or more and less than 0.10% C, 1.0% or more and 2.0% or less Si, 1.0% or more and 3.0% or less Mn, 0.020% or more and 0.100% or less P, 0.03% or less S, 0.01% or more and 0.5% or less sol. Al, and 0.005% or less N. The composition establishes 50(%Si)-39(%Mn)+200(%P)-10(%Cr)+40≥0. The balance includes iron and inevitable impurities. The structure includes 80% or more by volume fraction of ferrite phase as the main phase, and 1% or more of martensite phase. Further, TS×Rmin≥700 MPa, YR≤60%, and TS×El≥19,000 MPa% are established. Here, Rmin shows the minimum value of Lankford values of the rolling direction, the direction of 45°to the rolling direction, and the direction of 90°to the rolling direction, and YR shows yield ratio (=YS×100/TS). <P>COPYRIGHT: (C)2012,JPO&INPIT</p> |
