Strain-softening behavior of an Fe–6.5 wt%Si alloy during warm deformation and its applications

An Fe–6.5 wt%Si alloy with columnar grains was compressed at a temperature below its recrystallization temperature. The Vickers hardness and structure of the alloy before and after deformation were investigated. The results showed that with an increase in the degree of deformation, Vickers hardness of the alloy initially increased rapidly and then decreased slowly, indicating that the alloy had a strain-softening behavior after a large deformation. Meanwhile, the work-hardening exponent of the alloy decreased significantly. Transmission electron microscopy confirmed that the decrease of the order degree was responsible for the strain-softening behavior of the deformed alloy. Applying its softening behavior, the Fe–6.5 wt%Si alloy with columnar grains was rolled at 400 °C and then at room temperature. An Fe–6.5 wt%Si thin strip with thickness of 0.20 mm was fabricated. The surface of the strip was bright and had no obvious edge cracks.