| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method of producing a hot-dip galvannealed steel sheet excellent in press moldability by forming an oxide layer with sufficient thickness on a plated surface in a short period of time even under a high-speed production condition, and to provide the hot-dip galvannealed steel sheet produced thereby. <P>SOLUTION: The method of producing the hot-dip galvannealed steel sheet having the oxide layer on the plated surface includes: performing the alloying and temper rolling treatments on the plated steel sheet after hot dip galvanization; mixing, on the plated steel sheet, a first solution comprising the alkaline colloidal solution containing zinc hydroxide of ≥10 g/l in terms of Zn with a second solution comprising the acidic solution containing a sulfate ion of ≥5 g/l; and rinsing and drying the steel sheet after the lapse of a prescribed time to form a Zn- and S-containing oxide layer on the surface of the plated steel sheet. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
