PROCESS FOR PRODUCING GRAIN-ORIENTED ELECTRICAL STEEL STRIP AND GRAIN-ORIENTED ELECTRICAL STEEL STRIP OBTAINED ACCORDING TO SAID PROCESS

摘要

A process for producing a grain oriented electrical steel strip using a sheet continuous casting, said process comprising the steps of: a) melting steel; b) continuously casting the slurry by continuous casting of the sheet; c ') heating said lamina at a maximum temperature of 1250 ° C; d) heating to a temperature of 1350 캜 to 1380 캜; e) continuously hot rolling the thin plates to form a hot rolled strip; f) cooling and winding the hot-rolled strip to form a coil; g) unwinding the hot steel strip after winding and prior to the sequential cold rolling step; h) cold-rolling the hot-rolled strip to a nominally usable thickness; i) subjecting the cold rolled strip to recrystallization, decarburization and annealing; j) applying a release separator (non-tacky layer) to the strip surface of the cold rolled strip; k) subjecting the cold rolled strip to a second recrystallization annealing treatment to form a finished steel strip having a distinct goss texture; And l) stress-relieving the finished steel strip coated with the insulating layer, and providing an improved process for producing grain oriented electrical steel strip using the sheet continuous casting. This is achieved in that the recrystallization, decarburization and annealing steps of the cold-rolled strip in process step (h) comprise a decarburization annealing work step and a sequential annealing annealing work step, Is interposed between the decarburization annealing step and the annealing step and acts on the cold rolled strip with nitrogen (N ₂ ) and hydrogen (H ₂ ) and with a steam / hydrogen partial pressure ratio of less than 0.10 at a temperature in the range of 820 ° C to 890 ° C for a period of up to 40 seconds using the annealing atmosphere of a dry gas having a pH of ₂ O / pH ₂ , wherein the primary recrystallized grains have a diameter of from 22 μm to 25 μm A cold rolled strip having the same average size (diameter) is obtained.