METHOD FOR HIGH EFFICIENCY DESCALING AND PICKLING OF FERRITIC HEAT RESISTING STEEL SHEET

• Main Authors: TERAOKA SHINICHI, SAKAMOTO TOSHIHARU, FUTAKA MIKIO, IIDA HIDENORI
• Format: Patent
• Language: English
• Published: 27.10.2005
• Edition: 7
• Subjects: ALLOYS; 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; FERROUS OR NON-FERROUS ALLOYS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUSMETALS OR ALLOYS; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; MAKING METAL MALLEABLE BY DECARBURISATION, TEMPERING OR OTHERTREATMENTS; METALLURGY; METALLURGY OF IRON; MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; TREATMENT OF ALLOYS OR NON-FERROUS METALS

PROBLEM TO BE SOLVED: To obtain high pickling efficiency at a low cost in the case the ferritic heat resisting steel sheet is pickled by using mixed acids of a pickling accelerator containing sulfuric acid and mercapto group. SOLUTION: The amount of precipitated P is specified to ≥0.017% in pickling the ferritic heat resisting steel sheet containing, by mass, 0.0015 to 0.0080% C, 0.05 to 0.70% Si, 0.05 to 0.70% Mn, 0.017 to 0.035% P, 0.005 to 0.0010% S, 10.5 to 18.0% Cr, 0.001 to 0.050% Mo, 0.001 to 010% Cu, 0.0040 to 0.150% N, 10+(C+N)+2xP to 0.30% Ti, and the balance consisting of Fe and inevitable impurities by the mixed acids prepared by adding mercaptoacetic acid to sulfuric acid. COPYRIGHT: (C)2006,JPO&NCIPI