| 摘要 |
Provided is a cold-rolled steel sheet that exhibits excellent heat-spot resistance, wear resistance and blanking characteristics. The cold-rolled steel sheet includes, in terms of mass%, 0.03-0.08% C, 0-1.0% Si, 0.2-0.8% Mn, at most 0.03% P, at most 0.01% S, and at most 0.05% Al in proportions that satisfy the equation 5×C%-Si%+Mn%-1.5×Al%<1. The cold-rolled steel sheet also includes one or more of the elements Nb, V and Ti, such that the content of Nb is 0.03-0.4%, the content of V is 0.01-0.3%, and the content of Ti is 0.01-0.3% in proportions that satisfy the equation 0.04<(Nb%÷1.4)+(V%÷1.1)+Ti%<0.3. The average particle size of carbide precipitates is 20-100 nm. In cross section, second-phase structures having a length of 5μm or longer constitute at most 5% of the area of the total structure. |
