Improvement in the manufacture of oriented grain steel sheet. The improvement relates to coating step of the sheet with annealing separators in order to obtain a complete purification of the steel from harmful components as well as the production, during the annealing step, of a continuous and adherent layer of glass film having the same and constant thickness on both surfaces of the steel sheet.
The invention consists in that the coating of the sheet with said annealing separator is carried out from a suspension of annealing separator in a suspension medium having a non-aqueous base, preferably commercial ethyl alcohol containing limited and controlled amounts of water, using the continuously passing steel sheet as the cathode of an electrophoretic cell, the anodes being a couple of electrodes placed in, and near the free surface of, the bath, simmetrically with respect to the steel sheet.