| 摘要 |
PROBLEM TO BE SOLVED: To provide a cold rolled steel sheet that can demonstrate an excellent aging resistance in a stable manner.SOLUTION: A cold rolled steel sheet has a composition containing, by mass or mass ppm, 0.01-0.05% C, 0.2% or less Si, 0.5% or less Mn, 0.03% or less P, 0.02% or less S, 0.01% or less N, and 0.01-0.1% Al, and satisfying 10 ppm or less of solid solution C amount and 50 ppm or more of solid solution Al amount, with the remainder comprising Fe and unavoidable impurities, wherein 40% or more of the precipitating cementite precipitates in the ferrite grain boundary. |
