Regulating the recrystallized grain to induce strong cube texture in oriented silicon steel

Abstract

• Cube texture contains two easy magnetization direction 〈001〉 parallel to rolling and transverse direction respectively, which is the most ideal magnetic texture suitable not only for transformers but also for rotating machines. In this study, strong cube texture with ODF density of 50.73 mrd was successfully obtained by controlling orientation using pulsed electric current in finished oriented silicon steel. • To transform from Goss to cube texture in oriented silicon steel, cross cold rolling process intentionally “created” metastable deformed cube orientation in oriented silicon steel. • The effects of Joule heating and heating rate on the cube recrystallization texture were distinguished, which fills a significant gap in our knowledge of the mechanism of pulse electric current induced texture transformation. • This idea of current-controlled texture is worthy of popularization in more materials and the realization of electromagnetic field to crystal orientation selection is an interesting topic. Cube texture contains two easy magnetization directions 〈001〉 parallel to rolling and transverse direction, respectively, which is the most ideal magnetic texture suitable not only for transformers but also for rotating machines. In this study, a strong cube texture with ODF density of 50.73 mrd was successfully obtained by regulating the recrystallized grain orientation using cross-rolling and pulsed electric current, compared to conventional thermal annealing (the average cube texture intensity is ~10 mrd in lots of latest studies). Cross cold rolling process intentionally “created” metastable deformed cube orientation in oriented silicon steel and the specific recrystallization texture rotation path was identified under pulsed electric current in 5 min: {114}<261>→{114}<151>→{114}<041>→{001}<150>→{001}<010>. The cube-oriented grains were induced by pulsed electric current (800 °C) and rapid heating (51.9 °C/s, 750 °C), while the cube grains were observed in the annealed samples at the high temperature (1060 °C). Recrystallized grain size of pulsed samples is about twice that of the annealed sample. This phenomenon is considered that the concurrent effects of electron wind force and Joule heating affected the nucleation, growth and rotation of cube grains by reducing the nuclear barrier, producing higher grain boundary mobility and structural evolution towards a state with lower electrical resistance. This idea of current-controlled texture is worthy of popularization in more materials and the realization of an electromagnetic field to crystal orientation selection is an interesting topic.