Ultrastrong {100} texture in twin-roll strip cast non-oriented electrical steel through two-step annealing

Non-oriented silicon steel processed by twin-roll strip casting was cold rolled and followed by a new two-stage annealing process involving recovery annealing and recrystallization annealing. The microstructure from direct recrystallization annealing exhibited strong {100}<001> and obvious {111} texture. After introducing recovery annealing, the average grain size of the final recrystallized microstructure gradually increased with recovery temperature. Furthermore, the {100} texture in the two-stage annealed microstructure was significantly enhanced and attained a volume fraction of 47.6% on recovery annealing at 590°C. This is attributed to the fact that reduced deformation stored energy after recovery annealing enhanced recrystallization, extended recovery, and grain growth behavior of {100} grains. The development of ultra-strong {100} texture and increased grain size significantly improved the magnetic properties of the final annealed sheet.