Enhance the elongation of quenched Fe-6.5 wt.% Si alloy by adjusting ordered structures and residual stress

During cooling of Fe-6.5 wt.% Si alloy, the cooling rate affects the ordering process, which in turn influences the plasticity. Rapid quenching from the disordered phase region inhibits ordering and improves plasticity, but introduces residual stress that degrades workability to a certain extent. The microstructure and mechanical properties after stress relief annealing at 300–500°C were studied. Based on ordered structure morphology and resistivity heating curves, the critical ordering temperature was determined to be approximately 400°C. Annealing at 500°C or at 400°C for 20 h increased order degree and reduced elongation. By adjusting ordered structures and residual stress, the relatively appropriate stress relief annealing process is 400°C for 10 h, which further enhances the elongation.