PRODUCTION METHOD OF GRAIN-ORIENTED SILICON STEEL USING ONLY COLD ROLLING Russian patent published in 2012 - IPC C21D8/02 C21D9/46 C22C38/02 C22C38/60 

FIELD: metallurgy.

SUBSTANCE: proposed method involves the following: 1) melting, refining and continuous pouring so that cast workpiece is obtained; 2) hot rolling; 3) normalising annealing and cooling; 4) single cold rolling at reduction ratio of cold rolling of 75-92%; 5) decarburising annealing at 780-880°C during 80-350 seconds in protective atmosphere having dew point of 40-80°C, in which common oxygen [O] on the surface of decarburised plate: 171/t≤[O]≤313/t, where t - actual thickness of steel plate in mm, and number of absorbed nitrogen - 2-10 ppm; 6) high-temperature annealing, at which dew point of protective atmosphere is 0 to 50°C, temperature exposure time is 6 to 30 hours, and quantity of absorbed nitrogen during high-temperature annealing is 10-40 ppm; and 7) annealing with straightening during heating.

EFFECT: monitoring of microstructure of primary recrystallisation of steel plate and excluding the effect of nitration using ammonia, which contributes to formation of good appropriate layer.

6 cl, 5 ex, 10 tbl, 3 dwg