Title:
ELECTROGALVANNEALED STEEL SHEET HAVING EXCELLENT APPEARANCE
Document Type and Number:
Japanese Patent JP3233784
Kind Code:
B2
Abstract:
PURPOSE: To produce a galvanized steel sheet free from the generation of surface unevenness and excellent in whiteness, at the time of producing an electrogalvanized steel sheet, by adding tin to a pickling soln. for a steel sheet, precipitating tin on the surface of the steel sheet and thereafter executing electrogalvanizing.
CONSTITUTION: At the time of applying electrogalvanizing to a cold rolled steel sheet in which extremely small amounts of oxides such as silica, alumina, titanium or the like are segregated on the surface, in the case of pickling by an aq. soln. of sulfuric acid, the steel sheet is pickled by a soln. of sulfuric acid added with tin sulfate at 0.1 to 20g/l concn. to precipitate Sn on the surface of the steel sheet by the quantity of 0.5 to 10mg/m2. Next, this steel sheet immersed in an electrogalvanizing bath, is energized as the cathode and is electrogalvanized. The electrogalvanized steel sheet in which stripy unevenness caused by the segregation of oxides such as silica is not recognized and having high whiteness and excellent appearance can be produced.
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Inventors:
Takayuki Urakawa
Hideharu Koga
Toru Imokawa
Watanabe Toyofumi
Hideharu Koga
Toru Imokawa
Watanabe Toyofumi
Application Number:
JP18012694A
Publication Date:
November 26, 2001
Filing Date:
August 01, 1994
Export Citation:
Assignee:
Nippon Steel Tube Co., Ltd.
International Classes:
C23C28/02; C25D3/22; C25D5/26; C25D5/36; C25D5/50; (IPC1-7): C25D5/26
Domestic Patent References:
| JP4124295A | ||||
| JP5458635A |
Attorney, Agent or Firm:
Takehiko Suzue (4 outside)