SUSPENSION FOR SEPARATING AGENT DURING ANNEALING

PURPOSE: To stabilize the slurry, and to improve the blanking and core loss characteristics of the steel sheet after annealing by specifying the viscosity of the suspension when the ceramics suspension is used as the separating agent during the finish annealing of the grain-oriented silicon steel sheet. CONSTITUTION: The viscosity cp of the suspension as the aqueous solution is not less than 0.001 (ρ-1)D and >=5000 where D is the mean grain size (μm) of ceramics particles, ρ is the density (g/cm ) of ceramics particles, and ρ' is the density of the suspension (g/cm ). The ceramics particles are preferably non-hydrate. The suspension is the aqueous solution of water-soluble polymer binding agent, and the water-soluble polymer binding agent is either of cellulose ester, polyvinyl alcohol or polyethylene glycol. Thereby, sedimentation of ceramics particles in the slurry is suppressed and the slurry is stabilized.