Title:
METHOD FOR PRODUCING SURFACE-TREATED STEEL SHEET, AND SURFACE-TREATED STEEL SHEET
Document Type and Number:
WIPO Patent Application WO/2020/217663
Kind Code:
A1
Abstract:
Provided is a method for producing a surface-treated steel sheet, the method comprising subjecting a steel sheet having a Sn plating layer to an anodic electrolytic treatment in an alkaline aqueous solution to form a Sn oxide layer, and performing a cathodic electrolytic treatment in a zirconium ion-containing aqueous solution to form a coating layer containing a zirconium oxide, wherein: in the Sn plating layer, the adhesion amount of Sn is 0.1-20.0 g/m2 per one side of the steel sheet; the Sn oxide layer has a reduction current peak in the potential range of the -800 to -600 mVvs saturated KCl-Ag/AgCl reference electrode in a current-potential curve obtained by sweeping the potential, at a sweep rate of 1 mV/sec, from the immersion potential to the lower side, at the time of forming the Sn oxide layer, in a 0.001N hydrogen bromide aqueous solution of 25°C in which an inert gas is substituted; the electrical quantity of reduction current in the potential range is 1.5-10.0 mC/cm2; and in the coating layer containing the zirconium oxide, the adhesion amount of Zr is 0.1-50.0 mg/m2 per one side of the steel sheet.
Inventors:
UENO TAKASHI (JP)
SUTO MIKITO (JP)
YAMANAKA YOICHIRO (JP)
SUTO MIKITO (JP)
YAMANAKA YOICHIRO (JP)
Application Number:
PCT/JP2020/006236
Publication Date:
October 29, 2020
Filing Date:
February 18, 2020
Export Citation:
Assignee:
JFE STEEL CORP (JP)
International Classes:
C23C28/00; C25D9/08
Domestic Patent References:
| WO2015001598A1 | 2015-01-08 | |||
| WO2018190412A1 | 2018-10-18 |
Foreign References:
| JP2015158005A | 2015-09-03 | |||
| JP2018035394A | 2018-03-08 | |||
| JP2018135569A | 2018-08-30 |
Other References:
See also references of EP 3960900A4
Attorney, Agent or Firm:
SUGIMURA Kenji (JP)
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