Strong NbC particle pinning for promoting abnormal growth of Goss grain in Fe82Ga4.5Al13.5 rolled sheets

Abstract

A great number of fine and dispersive NbC precipitates were obtained in Fe82Ga4.5Al13.5 sheets by rolling process consisting of hot rolling at 900°C, warm rolling at 500°C and intermediate annealing at 650°C for 15min. The mean size of precipitates in primarily recrystallized sheets is ∼45nm. Grain growth in final sheets was investigated to study the influence of fine precipitates on the promotion of abnormal grain growth (AGG). Fully developed AGG of Goss grain was observed in samples with the heating rate during continuous process of 0.5°C/min, 1°C/min and 2°C/min. In contrast, AGG in samples of 0.25°C/min and 4°C/min were partially developed. The influence of heating rate on the development of AGG was examined by the investigation of precipitates and grain configurations during continuous heating process. With the fine precipitates, sharp Goss orientation was developed in Fe82Ga4.5Al13.5 sheets annealed at Ar atmosphere. A maximum saturation magnetostriction of 170ppm was obtained in sample of 2°C/min.