Unidirectional cold rolling of Fe-21Cr-5Mn-1.5Ni alloy – Microstructure, texture and magnetic properties

Abstract

In the present work, changes in microstructure, texture and magnetic properties during unidirectional cold rolling of a Fe-21Cr-5Mn-1.5Ni alloy were investigated. For microstructural characterization, scanning electron microscope (SEM) and electron backscattered diffraction (EBSD) were used, while for bulk texture measurements, X-ray diffraction (XRD) was used. Magnetic measurements (M-H and B-H curves) were used to characterize the strain induced martensite (SIM). The band thickness (thickness of grain along normal direction (ND)) reduced significantly more in austenite, than in ferrite with increasing deformation (cold rolling). Also, during deformation, more strain was partitioned in austenite than in ferrite. The saturation magnetization increased with increase in cold rolling reduction and SIM was ∼ 11% after 80% cold rolling. The as-received sample showed strong cube ({100} 〈100〉 ) and Brass ({110} 〈112〉 ) in austenite and strong α (RD//〈110〉 ) and γ (ND//〈111〉 ) fibres in ferrite. After 80% cold rolling, strong Brass ({110} 〈112〉 ) and Goss ({110} 〈001〉 ) were developed in austenite, while the existing α and γ fibres further strengthened in ferrite. The area under the B-H curve was found to be proportional to strain. Both texture and strain were found to be responsible for this increase.