Effect of annealing treatment prior to cold rolling on the final microstructure and magnetic properties of an ultra-low carbon non-oriented Si-Sb electrical steel

In this work, the effect of annealing prior to cold rolling on the final microstructure, grain size and magnetic properties of ultra-low carbon Si-Sb steel sheets was studied. Annealing was applied to hot-rolled steel strips at 880 degrees C for times of 30 min, 60 min, 90 min, 120 min, 150 min, and 180 min. Results show that, annealing of hot-rolled strips promote a selective grain growth, which leads to microstructures with a significant larger grain size. Modification of the hot-rolled material was followed by cold rolling to achieve a thickness of 0.25 mm and final annealing treatment at 850 degrees C for 60 min. Finally, magnetic properties of cold rolled and annealed samples were evaluated at 0 degrees, 45 degrees and 90 degrees with respect to the rolling direction.