| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method for stably manufacturing a galvannealed steel sheet which shows superior slidability in a press molding step, and is satisfactorily degreased in an alkaline degreasing treatment that is conducted before chemical conversion treatment, and to provide the galvannealed steel sheet. <P>SOLUTION: The method for manufacturing the galvannealed steel sheet includes the steps of: hot-dip galvanizing a steel sheet; further alloying the galvanizing layer by heat treatment; temper-rolling it; and forming a Zn oxide layer with a thickness of 10 nm or more, on the surface of the galvannealed steel sheet, through making the galvannealed sheet contact with an acid solution, leaving it for 1 to 30 seconds after the contact has been finished, and rinsing it. The method also includes using an aqueous solution containing P in an amount of 0.5 to 5,000 ppm. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
