PRODUCTION OF RANDOM-ORIENTATION ELECTRIC STEEL WITH HIGH MAGNETIC INDUCTION Russian patent published in 2014 - IPC C21D8/12 C22C38/34 C22C38/40 H01F1/16 

FIELD: metallurgy.

SUBSTANCE: invention relates to production of electric steel. Proposed process comprises melting the steel of the following chemical composition, wt %: Si 0.1-1, Al 0.005-1.0, C≤0.004, Mn 0.10-1.50, P≤0.2, S≤0.005, N≤0.002, Nb+V+Ti≤0.006, Fe and unavoidable impurities making the rest. Steel bar ingot is produced and heated to 1150-1200°C. It is kept at said temperature for definite time and subjected to hot rolling at 830-900°C to steel strip. The latter is cooled to ≥570°C and coiled. Hot-rolled strip is straightened by cold rolling at reduction factor of 2-5%. Cold-rolled strip is continuously normalised at, at least 950°C and held thereat for 30-180 s. Normalised strip is etched and cold rolled with total reduction factor of 70-80% to get the sheet of target depth. Said sheet is annealed by heating at the rate of 100°C/s to 800-1000°C. It is held at this temperature for 5-60 s and slowly cooled down to 600-750°C at the rate of 3-15°C/s.

EFFECT: magnetic induction increased by at least 200 GSt.

2 cl, 3 tbl, 2 ex, 1 dwg