| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-carbon cold-rolled steel sheet which is excellent in workability, and can be manufactured without using a multistage annealing technique that needs a long period of time. SOLUTION: The cold-rolled steel sheet has Fe oxide controlled to 10 mg/m<SP>2</SP>or less and Mn oxide in an amount of 1.0 or more by a mass ratio to the total oxides amount of Al, Ti and Si, on the surface of the steel sheet. The method for manufacturing the cold-rolled steel sheet includes controlling an atmosphere gas in the step of batch annealing carried out after having cold-rolled a hot-rolled steel plate , so as to contain 80% or higher hydrogen, have a dew point controlled to 30°C or lower when the coldest point of a coil in an annealing furnace is 200°C or higher, and further have a dew point controlled to -20°C or lower when the coldest point of the coil in the annealing furnace is 600°C or higher. COPYRIGHT: (C)2007,JPO&INPIT
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