PROCESS FOR PRODUCTION OF ANISOTROPIC ELECTRIC STEEL Russian patent published in 1999 - IPC

FIELD: ferrous metallurgy. SUBSTANCE: process includes smelting, hot rolling, decarbonization, double cold rolling, retarded heating during primary recrystallization period, and final high- temperature annealing. To increase magnetic properties and stabilize secondary recrystallization of steel, heating temperature of hot rolling (T) is set in dependence of aluminum content in steel expressed by relationship: T = 1190 + 4x10% Al ± 10^3°C . Coiling is accomplished at 520- 570 C. Retarded heating is effected (i) after final cold rolling with rate 5- 15 C/hr over a temperature range of 400 to 700 C with probability of decarbonization in smelting stage or (ii) after heat treatment of strip plate with initial, intermediate, or final thickness and probability of addition of 0.2-0.7% of copper to steel. EFFECT: enhanced process efficiency. 3 cl, 2 tbl