METHOD OF PRODUCING ZINC-PLATED STRIP STEEL FOR SUBSEQUENT APPLICATION OF HIGH-QUALITY PAINT COATINGS Russian patent published in 2000 - IPC

FIELD: production of steel strips with coatings. SUBSTANCE: method may be used in mechanical engineering and other industries using sheets with hot-dip galvanized coating for subsequent application of paint coatings. The method includes cold rolling of sheets with surface roughness (Ra) equalling 1.1-1.5 mcm and peak density of 80-160 per cm and after hot-dip galvanizing, wet temper rolling is effected with 0.5-0.8% reduction on rolls with surface roughness equalling 2.5-3.0 mcm and peak density of 150-200 per cm after their preliminary running in planishing stand without sheet, with specific force of 100-200 N/sq.mm for 0.1-0.3 h with cleaning of working surface of roll barrels. Roll ragging is accomplished by cathode treatment in chromium salt solution with cathode density of current of 30-60 A/sq.dm, voltage of 300-340 V and roll rotation speed of 0.1-0.8 m/s. Temper rolling is carried out with supply of water mist (aerosol) of distilled water simultaneously to both rolls, upper and lower surfaces of sheet at inlet of stand. Isotropism of roll roughness amounts to 0.90-0.95 and continuous cleaning of their barrels is carried out at stand outlet side. EFFECT: excluded peeling and shelling of painted layer. 5 cl, 1 ex