EXTRA LOW-CARBON THIN STEEL SHEET AND MANUFACTURING METHOD THEREFOR

摘要

PROBLEM TO BE SOLVED: To provide a thin steel sheet with a thickness of 0.30 mm or more, which can inhibit failures during forming such as pin hole and press crack initiating from inclusions, even when extra low-carbon steel containing 0.010% or less C is provided to a use such as a case for an electric motor or a case for an oil cleaner, for which complicated high deformation is needed.;SOLUTION: This thin steel sheet comprises having a chemical composition containing 0.010% or less C, 0.5% or less Si, 1.5% or less Mn, 0.12% or less P, 0.030% or less S, 0.10% or less Ti, 0.08% or less Al, 0.0080% or less N, and making the total number of observed non-metallic inclusions in 60 visual fields based on JIS G0555, as 20 or less. This manufacturing method comprises controlling (FeO)+(MnO) in ladle slag during continuous casting, to be 15% or less, and a throughput rate during casting to be 5 Ton/minute or less.;COPYRIGHT: (C)2002,JPO