The significance of Ce on hot compression deformation and mechanical behavior of Fe–6.9 wt%Si alloy: Decrease of order degree and transformation of dislocations

Abstract

The significance of Ce on the hot compression deformation and mechanical behavior of Fe–6.9 wt%Si alloy was elucidated in order to improve the plastic deformation. The study revealed that the flow stress of non-Ce-doped alloy was higher than Ce-doped alloy during deformation in the temperature range of 400–640 °C. The improvement in mechanical properties of Fe–6.9 wt%Si alloy was governed by the decrease of order degree and transformation of dislocations because of Ce addition. Addition of rare earth Ce reduced the content of B2 ordered phase, and inhibited the formation of DO3 ordered phase because of solid drag effect of Ce on Fe and Si atoms during atom vacancy diffusion. Additionally, the ferrite grains were refined, and the majority of superdislocations were transformed into single dislocations after added Ce into steel, increasing the mobility of dislocations. Thus, the average fracture deflection of warm-rolled sheets increased from 8.1 mm to 15.6 mm, which implied that Ce addition had contributed to the plastic deformability of Fe–6.9 wt%Si alloy.