High-strength cold-rolled steel sheet excellent in uniform elongation and method for manufacturing same

摘要

A high-strength cold-rolled steel sheet excellent in uniform elongation, including in percent by mass:
0.10-0.28% of C;1.0-2.0% of Si; and1.0-3.0% of Mn,

and the structures of the same having the space factors below to the entire structure:
30-65% of bainitic ferrite;30-50% of polygonal ferrite; and5-20% of residual austenite.

主权项

1. A high-strength cold-rolled steel sheet excellent in uniform elongation, comprising in percent by mass (which is hereinafter applied similarly to chemical components):
0.10-0.28% of C; 1.0-2.0% of Si; and 1.0-3.0% of Mn,wherein the structure of the high-strength cold-rolled steel sheet is:
40-65% of bainitic ferrite; 30-50% of polygonal ferrite; and 9-17% of residual austenite;and wherein the product of its tensile strength (TS) in MPa and total elongation (EL) in % (TS×L) is 23,000 or more.