| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a galvannealed steel sheet having a uniform oxide layer on its surface and excellent in press forming property. SOLUTION: The galvannealed steel sheet excellent in press forming property is obtained by successively allowing a steel sheet to be subjected to a galvanizing step, an alloying step, a temper rolling step, and an oxide layer forming step in which an acid solution is brought into contact with a surface of the steel sheet, a liquid film of the acid solution is deposited thereon, the steel sheet is squeezed by two or more pairs of continuous squeezing rolls, the acid solution is reacted with the galvannealed layer to deposit an oxide layer on the surface of the galvannealed layer. Thus, the oxide layer of the predetermined thickness or more can be formed with less dispersion in the sheet width direction. COPYRIGHT: (C)2007,JPO&INPIT
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