| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a high-strength cold-rolled steel sheet which has superior balance between tensile strength and elongation, has superior balance between tensile strength and uniform elongation, and is optimal for a material of an automotive member and a pillar to be bulged, and to provide a useful method for manufacturing such a high-strength steel sheet. <P>SOLUTION: The high-strength cold-rolled steel sheet has a steel composition including, by mass%, 0.10-0.28% C, 1.0-2.0% Si and 1.0-3.0% Mn, and has a structure including 30-65% of bainitic-ferrite, 30-50% of polygonal-ferrite and 5-20% of retained austenite by a space factor with respect to the total structure. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
