Title:
PRODUCTION OF ELECTROLYTIC CHROMATE TREATED STEEL SHEET HAVING EXCELLENT SURFACE APPEARANCE
Document Type and Number:
Japanese Patent JP3216383
Kind Code:
B2
Abstract:
PURPOSE: To produce an electrolytic chromate treated steel sheet having excellent surface appearance by forming a lower layer consisting of metal chromium and an upper layer consisting of a chromium oxide hydrate under specific conditions at the time of allowing the steel sheet to travel perpendicularly in an electrolytic by a sink roll and subjecting the steel sheet to a cathode electrolyte treatment.
CONSTITUTION: Nonconductive members 3 having a length of ≥1/3 the length of anode electrodes 2 are successively joined to te bottom end of the anode ectrode 2 on the descending side of the steel sheet 1 and the bottom end of the anode electrode 2 on the ascending side of the steel sheet 1 at the time of producing the electrolytic chromate treated steel sheet by allowing the steel sheet 1 to travel perpendicularly in an electrolyte by the sink roll 5 and subjecting the steel sheet to a cathodic electrolytic treatment and then, the electroless part of dummy electrode is formed. The steel sheet 1 is subjected to the cathodic electrolytic treatment at a current density of ≥50A/dm2 by this constitution, by which the lower laver consisting of the metal chromium having a granular projection density of ≤20pieces/μm2 and the upper layer of the chromium oxide hydrate of 3 to 25mg/m2 in terms of chromium are formed. As a result, the electrolytic chromate treated steel sheet having the excellent surface appearance is produced at a reduced initial cost and production energy.
Inventors:
Hideki Nishihara
Yoshitaka Kashiyama
Mitsuo Hoku
Shinsuke Watanabe
Yoshitaka Kashiyama
Mitsuo Hoku
Shinsuke Watanabe
Application Number:
JP35536193A
Publication Date:
October 09, 2001
Filing Date:
December 29, 1993
Export Citation:
Assignee:
Nippon Steel Tube Co., Ltd.
International Classes:
C25D17/10; C25D11/38; (IPC1-7): C25D11/38
Domestic Patent References:
| JP59100291A | ||||
| JP4619522B1 | ||||
| JP436367B1 |
Attorney, Agent or Firm:
Shigeru Takano
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