| 摘要 |
A process for forming a refractory coating on silicon-iron stock prior to an annealing operation comprises applying a thin binder layer in liquid form to one clean side of the stock, passing the coated stock into adherent contact with fine particles of a refractory separator substance and vaporizing the binder to leave a thin porous coating of the refractory particles on the stock for the annealing operation. The vaporization temperature of the binder materials must naturally be below the anneling temperature, and the binder may be solute-vehicle combinations like polyvinyl alcohol-water, wheat paste or ureaformaldehyde with water, and latex-type adhesive with benzene or naphtha. Magnesium hydroxide, alumina, non-hydrated magnesia, zirconia, and tit</>aania are preferred refractories applied by screening, electrostatic precipitation or fluidized bed technique to the liquid binder layer which is itself formed by coating rolls, doctor blades or sprays on the pickled, degreased or burnt surface of the stock. One or both sides of the stock are coated, binder coatings being about 0.001 inch thick and the separator layer 0.002-0.003 inches. The solvent vehicle may be driven off by gentle heat or hot air blasts. The solute may be vaporized during the anneal itself. The Si, C, S and Mn contents of the ladle analyses are specified.ALSO:A process for forming a refractory coating on silicon-iron stock prior to an annealing operation comprises applying a thin binder layer in liquid form to one clean side of the stock, passing the coating stock into adherent contact with fine particles of a refractory separator substance and vaporizing the binder to leave a thin porous coating of the refractory particles on the stock for the annealing operation. The vaporization temperature of the binder materials must naturally be below the annealing temperature, and the binder may be solute-vehicle combinations like polyvinyl alcohol-water, wheat paste or ureaformaldehyde with water, and latex-type adhesive with benzene or naphtha. Magnesium hydroxide, alumina, non-hydrated magnesia, zirconia, and titania are preferred refractories applied by screening, electrostatic precipitation or fluidised bed technique to the liquid binder layer which is itself formed by coating rolls, doctor blades or sprays on the pickled, degreased or burnt surface of the stock. One or both sides of the stock are coated, binder coatings being about 0.001 inch thick and the separator layer 0.002-0.003 inches. The solvent vehicle may be driven off by gentle heat or hot air blasts. The solute may be vaporized during the anneal itself. The Sc, C, S and Mn contents of the ladle analyses are specified. |
