| 摘要 |
PROBLEM TO BE SOLVED: To provide ultralow carbon steel which hardly allows surface defects, especially surface defects due to oxide scales, to appear on the surface; and a continuous casting method for preparing the ultralow carbon steel. SOLUTION: The ultralow carbon steel is continuously cast so that the concentration (mass%) of at least one element selected from among Si, Al, Nb, and Ti in the steel satisfies the relational expression: 11.5×%Si+47×%Nb+49×%Ti+52×%Al≤4. In the ultralow carbon steel having been subjected to a heat treatment before hot rolling, the average intergranular oxidation depth at the interface between scales and base iron of the steel surface is controlled to 50μm or less. COPYRIGHT: (C)2004,JPO
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