When rolling a tape 0.35 mm thick: squeezing from 0.7 to 0.38-0.39 mm, the supply of emulsion from the back side of the camp, t. e. With the first squeezing, the lanes and the supply of emulsion from the front side of the camp are made to cool the rolls. Pass with compression from 0.38 to 0.35 mm, usually when oil supply, and sometimes on the emulsion. At the Zaporizhstal factory, experiments were carried out as a technological lubricant during cold rolling of transformer steel Salomas (hydrated sunflower oil). At the same time, good results were obtained: the hood of metal improved, energy consumption decreased and the surface quality improved. But due to the high cost, this lubricant for the specified purpose is not used. Deflection stations.
After cold rolling before annealing, it is recommended to rinse to clean its surface from oil residues and emulsion. During rolling, the lubricant is pressed into the surface of the metal. With an increase in temperature to 100-200 ° C, a grease and carbon monoxide of the metal surface can occur. Therefore, before applying the electrical insulating films, the surface of the strip must be thoroughly cleaned. Washing of sheets is also necessary to improve the conditions of coating of a band with a magnesium oxide with or talcum in front of high -temperature annealing.
To degrease the strip after cold rolling, various methods can be used, including electrolytic, chemical, ultrasonic.
Flushing cold -rolled transformer steel is sometimes done with gasoline.
With insufficient cleaning of the surface of the strip after cold rolling from lubrication residues during subsequent heat treatment due to the veil of the metal, the magnetic properties of the steel worsen.
According to the Novolipetsk plant, poor degreasing strip after cold rolling can worsen the specific losses of the finished sheet by 10-15%.
