Title:
METHOD FOR CONTROLLING PH IN ELECTROLYTIC TREATMENT OF STEEL SHEET
Document Type and Number:
Japanese Patent JPS624900
Kind Code:
A
Abstract:
PURPOSE:To highly stabilize the pH value of a processing soln. in a line tank by obtaining the hydrogen ion practically participating in the pH variation among the hydrogen ions respectively generated in electrolysis and the charge of liq. chemicals and successively controlling the variation of pH. CONSTITUTION:In a system, for example, for forming a hydrated chromium oxide layer on a tin-plated steel sheet by chemical conversion treatment, a pH meter 1 and a line tank 2 for chemical conversion treatment are provided, and a sodium bicarbonate soln. is circulated by a pump 8 between a circulation tank 3 and the line tank 2. The pH of the circulating soln. is monitored by the pH meter 1 and the level of the circulation tank 3 is always monitored by a level meter 4. The monitored values are outputted to a controller 5. The variations per unit time of pH which is raised and lowered by the reaction and the variations per unit time of pH which is raised and lowered by the effect of liq. chemicals which are charged to regulate the pH are obtained by the controller 5 and the amt. of a sodium bicarbonate soln. to be supplied from a service tank 7 is controlled so that both variations are equalized.
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Inventors:
SAISUU MASAHARU
AKAGI HIROMITSU
AKAGI HIROMITSU
Application Number:
JP14384485A
Publication Date:
January 10, 1987
Filing Date:
July 02, 1985
Export Citation:
Assignee:
KAWASAKI STEEL CO
International Classes:
C25D21/14; C25D11/38; G05D21/00; (IPC1-7): C25D11/38; C25D21/14; G05D21/00
Attorney, Agent or Firm:
Akihide Sugimura
Next Patent: PRESERVATION TREATMENT OF CORPSE AND AGENT THEREFOR