Title:
PRODUCTION OF COMPOSITE ELECTROPLATED STEEL SHEET HAVING HIGH CORROSION RESISTANCE
Document Type and Number:
Japanese Patent JPH04110498
Kind Code:
A
Abstract:
PURPOSE:To improve surface appearance as well as to render high corrosion resistance by adding boric acid to a plating bath contg. Zn<2+> ions, Cr<3+> ions, divalent ions of an iron family metal and a cationic polymer and carrying out electroplating at a specified flow velocity of the resulting plating bath and a specified current density. CONSTITUTION:A steel sheet is electroplated with a plating bath contg. Zn<2+> ions, Cr<3+> ions, divalent ions of an iron family metal, 0.01-20g/l cationic polymer and 5-100g/l boric acid at >=10m/min flow velocity of the bath and >=50A/dm<2> current density to obtain a composite electroplated steel sheet having high corrosion resistance. A quat. amine polymer is preferably used as the cationic polymer. In order to inhibit the occurrence of unevenness on the plated appearance in a high current density region of >=50A/dm<2> by adding boric acid, it is necessary to regulate the flow velocity of the plating bath to >=10m/min.
Inventors:
YAMAZAKI FUMIO
SHINDO YOSHIO
SHINDO YOSHIO
Application Number:
JP22837790A
Publication Date:
April 10, 1992
Filing Date:
August 31, 1990
Export Citation:
Assignee:
NIPPON STEEL CORP
International Classes:
C25D15/02; (IPC1-7): C25D15/02
Attorney, Agent or Firm:
Inoue Masao