| 摘要 |
PURPOSE: A low-carbon cold rolled steel sheet with excellent workability and a manufacturing method thereof are provided to improve strength from pinning effect where precipitates restrict the growth of crystal grains. CONSTITUTION: A low-carbon cold rolled steel sheet with excellent workability comprises 0.0016-0.0025wt.% of C, 0.05-0.2wt.% of Mn, 0.08wt.% or less of P, 0.008wt.% or less of S, 0.003-0.007wt.% of Si, 0.02-0.05wt.% of Al, 0.02-0.07wt.% of Ti, 0.001-0.005wt.% of N, and the remaining amount of Fe and inevitable impurities. The microstructure of the steel sheet has an average grain size of 7-11μm, 30-60 area% of crystal grains with a grain size of 10μm or less to the whole crystal grains, and 80% of precipitates with an aspect ratio of 3.5 or less to the total number of precipitates.
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