| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing ultra-low carbon steel having excellent material uniformity in the thickness direction, in which the ultra-low carbon steel with the constant carbon concentration from a surface layer to the inner side is manufactured while suppressing decarburization and carburization of the slab surface layer part when heating a slab during the hot rolling.SOLUTION: When the slab containing C of 0.0005-0.01 mass% is heated and hot-rolled to manufacture the ultra-low carbon steel, heating is performed while the value of the parameter A (=Cg/(Cs/100)-T/1,000), which is obtained by the slab heating temperature T(°C), the carbon activity Cg(atm) in the atmosphere of a heating furnace, and the carbon concentration Cs(mass%) contained in steel is set in an adequate range of (23.5≤A≤28.5). |
