| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a steel sheet by which excellent chemical convertibility can be obtained over the whole length and the whole width of the steel sheet.SOLUTION: The method for manufacturing the steel sheet in a continuous annealing facility includes a combustion-type heating furnace and a successive annealing furnace. In the combustion-type heating furnace, the steel sheet is heated while blowing gas having oxidizing action in addition of combustion gas, thereafter the steel sheet is annealed in the annealing furnace. Even a high-strength cold-rolled steel containing Si can sufficiently secure the oxidizing quantity, and even in the non-ordinary part when changing the size of the steel sheet, the oxidized quantity can sufficiently be secured and the uniform inner oxidized layer can be generated, thereby manufacturing the steel sheet excellent in the chemical convertibility over the whole length and the whole width. |
