ANALYSIS OF THE FORMATION AND GROWTH OF RECRYSTALLIZING GRAINS IN IF STEELS BY IN-SITU EBSP

摘要

In-situ SEM-EBSD microstructural analysis on IF steels was performed for direct observation and quantifying the recrystallization processes up to 800°C. Analysis of the data enabled the orientation relationships between each deformed grain and the new recrystallized grains in the same area to be determined.After a strain of 1.6, it is found that {111}<123> grains are preferentially formed from deformed y-fibre. It is also found that in the initial stages of recrystallization of this sample there is a preferred rotation angle of ～30° between the deformed and recrystallizing grains. During the later stage of recrystallization, the growing grain encounters other deformed grains, and if they have higher misorientation (>40°) then it is found that the growth rate is much lower. The present observations indicate that there is no strong evidence of a 27°/<110> relationship between deformed and recrystallized grains, as has been previously suggested. In a sample deformed to the lower strain of 0.75, it was found that the rotation angle and axis between deformed and recrystallized material tended to be random, the former peaking at ～50°.