STRIP FOR MAKING KINESCOPES Russian patent published in 2004 - IPC

FIELD: rolled stock production, namely manufacture of precision cold rolled strip for making shadow masks of kinescopes. SUBSTANCE: method comprises steps of decarburizing annealing of rolled piece; multiple cold rolling of it by two stages at intermediate recrystallization annealing of coiled strip; further dulling of strip surface due to rolling it between rough rolls; at first and second stages performing cold rolling between rolls with roughness degree of surface in range 0.10 -0.30 micrometers Ra and at specific front and rear tension of strip in range 60 - 160 H/sq.mm; sustaining total reduction value during second stage of multiple cold rolling in range 40 - 60%; realizing further dulling by 2 - 4 passes at reduction degree 0.6 - 2.0% for each pass between rolls with roughness degree 1.5 - 3.5 micrometers Ra at density of peaks 80 -180 1/sm. It is possible before decarburizing annealing to perform thickness calibration of strip rolled at reduction degree 3 - 3%. Before first stage of cold rolling strip is rolled in addition during one pass at reduction degree 13 -17% and at specific front and rear tension values in range 20 - 60 H/sq.mm. Before recrystallization annealing strip is degreased and it is coiled at specific tension 5 - 10 H/sq.mm. After annealing coiled strip is rewound at specific tension 60 -120 H/sq.mm. Coiled strip is subjected to recrystallization annealing due to heating it until temperature 610 - 640 C while soaking it at such temperature for 9 - 12 h. EFFECT: enhanced mechanical and magnetic properties, improved accuracy and planeness of strip, high quality of its surface. 5 cl, 3 tbl, 4 ex