Grain boundary sliding associated with low strain rate at 1000°C in recrystallized ODS ferritic steel

The high-temperature deformation process of the recrystallized 16CrODS ferritic steel was investigated at 1000 degrees C for the stress loading perpendicular to the elongated grain structure. The strain rate was varied in the range from 1.0 x 10(-2) to 1.0 x 10(-5) s(-1). At the strain rate over 1.0 x 10(-4) s(-1), deformation is dominated by the conventional dislocation creep. Decreasing strain rate from 1.0 x 10(-4) s(-1), grain boundary sliding becomes prominent. Accommodation process for the localized stress induced by grain boundary sliding could be dislocation creep at 1.0 x 10(-4) s(-1), and by diffusional creep at 1.0 x 10(-5) s(-1) or less. These were verified through the observation of void formation and localized strain accumulation by KAM map. (C) 2016 Published by Elsevier Ltd.