Metallurgical conditions for development of adequate magnetic properties in grain oriented silicon iron

The mechanisms underlying the secondary recrystallization process in connection with the production of grain-oriented silicon iron have recently been clarified, throwing light on the microstructural parameters and the relationships which control the development of the final orientation. In particular, the interrelationships among grain growth, texture, and the presence of second-phase particles and/or segregating atoms has been quantified. The conditions which cause drastic deterioration in magnetic properties are analyzed here in terms of simple microstructural parameters, namely, the inhibition factor, which describes the amount of restraining force on grain growth, and the effective grain radius, which takes into account the driving force caused by grain boundary curvature and microstructural heterogeneity. It is shown that several independent process variables contribute to the modification of the microstructural parameters responsible for the secondary recrystallization instability and therefore for the magnetic properties