METHOD FOR PICKLING COLD ROLLED STEEL SHEET FOR ELECTROPLATING BEFORE COLD ROLLING

• Main Authors: HAGIWARA HITOSHI, UEDA ARATA
• Format: Patent
• Language: English
• Published: 12.12.1991
• Subjects: APPARATUS THEREFOR; CHEMICAL SURFACE TREATMENT; CHEMISTRY; CLEANING OR DEGREASING OF METALLIC MATERIAL BY CHEMICALMETHODS OTHER THAN ELECTROLYSIS; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; ELECTROFORMING; ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; PROCESSES FOR THE ELECTROLYTIC OR ELECTROPHORETIC PRODUCTIONOF COATINGS

PURPOSE:To remove inclusions present under the surface of a steel sheet by setting pickling time on the basis of the percentage of total iron in slag at the end of degassing in a smelting stage when the steel sheet is pickled before cold rolling to remove the scale formed during hot rolling. CONSTITUTION:When a hot rolled steel sheet is pickled before cold rolling to remove scale formed during hot rolling, pickling time T (min) is set according to an inequality T>=0.06X(T.Fe)% (where T.Fe is total iron in slag at the end of degassing). Inclusions present under the surface of the steel sheet are removed and the occurrence of white streak defects on an electroplated steel sheet is prevented.