Effect of posttreatment on microstructure and magnetic properties of Si steel strips prepared by twin-roll continuous casting process

On the basis of early works, Si-steel strips with 3.0 wt pct Si content were prepared by twin-roll continuous casting (TRCC); posttreatment of double cold-rolling with different annealing temperature was completed, and accordingly, optimum parameters were ascertained. The microstructure and magnetic properties of the strips before and after posttreatment were investigated. The results indicated that Si steel strips could be successfully prepared by TRCC, and the best annealing conditions for posttreatment were 1223 K (950 °C) × 3 minutes in the Ar. Si steel strips exhibited the best magnetic properties after optimum posttreatment: core loss of 4.31 W/Kg and magnetic induction intensity of 1.69T. Moreover, proper posttreatment resulted in ordering of Fe₃Si of the Si steel strips, and this ordering was a key factor on improvement of magnetic properties.