METHOD FOR PREVENTING DISCOLORATION OF STEEL SHEET

• Main Authors: MORI TOSHIKAZU, SOUDEN NAOKI, NASU SHOGO, FUJII YUKIO, YAMAMOTO KAZUO
• Format: Patent
• Language: English
• Published: 11.07.1995
• Edition: 6
• 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; ELECTROLYTIC OR ELECTROPHORETIC PROCESSES; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; MULTI-STEP PROCESSES FOR SURFACE TREATMENT OF METALLICMATERIAL INVOLVING AT LEAST ONE PROCESS PROVIDED FOR IN CLASSC23 AND AT LEAST ONEPROCESS COVERED BY SUBCLASS C21D OR C22F OR CLASS C25; NON-MECHANICAL REMOVAL OF METALLIC MATERIAL FROM SURFACE; PROCESSES FOR THE ELECTROLYTIC REMOVAL OF MATERIALS FROMOBJECTS

PURPOSE:To prevent the discoloration of a high-quality and highly economical steel sheet which has been cleaned or electrolytically cleaned with an alkali. CONSTITUTION:In this method, a discoloration preventive agent or a cleaning water mixed with the agent is applied on a traveling steel sheet which has been cleaned and/or electrolytically cleaned with alkali, when the sheet is stopped or travels at a speed of <=50m/min, to prevent the discoloration of the sheet. Consequently, the steel sheet with the surface activated is prevented from being discolored, the quality and yield of the product are improved, and the economy of the discoloration preventive agent is improved.