PHOSPHORIC ACID-BASED INSULATING FILM-PROCESSING FLUID FOR ELECTRICAL STEEL SHEET HAVING EXCELLENT IDENTIFIABILITY BEFORE AND AFTER STRESS RELIEF ANNEALING AND CAPABLE OF PERFORMING LOW-TEMPERATURE HARDENING AND ELECTRICAL STEEL SHEET WITH PHOSPHORIC ACID-BASED INSULATING FILM

摘要

PROBLEM TO BE SOLVED: To provide a phosphoric acid-based insulating film-processing fluid for an electrical steel sheet having excellent appearance after hardening and identifiability before and after stress relief annealing and capable of performing low-temperature hardening. SOLUTION: The insulating film-processing fluid prepared by compounding a compound containing one or two or more kinds of metals selected from the groups IIIA, IVA, VIA (excluding Cr), VIIA, VIII and IB of the periodic table at 1 to 50 parts by weight, a compound containing metals of the groups IA and IIA of the periodic table at≤3 parts by weight in terms of the total amount of the metals, a compound of 110 to 250°C in a boiling point or a decomposition point at which gas is generated at 0.1 to 20 parts by weight as the weight of the gas, and a nonionic surfactant at 0.001 to 2 parts by weight, per 100 parts by weight phosphoric acid (in terms of H3PO4) is used as the insulating film-processing fluid. COPYRIGHT: (C)2006,JPO&NCIPI