During the heavy warm rolling process, austenite undergoes dynamic recrystallization (either DDRX or CDRX), and then transforms into martensite upon quenching. Is there a way to distinguish from the final martensitic structure in EBSD which parts have transformed from recrystallized austenite? Among the points that are particularly important and challenging for me are:
1. Recrystallization occurs during the processing, and the subsequent martensitic phase transformation through the K-S relationship can affect the judgment of grain orientation (for instance, FCC DRX may produce Σ3 twin boundaries, and the variants after martensitic transformation might also have Σ3 grain boundaries).
2. The nucleation of martensite in the austenite with strong plastic deformation is influenced by the strain gradient and may nucleate along the path that minimizes energy most rapidly. The nucleation of martensite during the phase transformation might affect the degree of intragranular distortion, and the original austenite intragranular distortion may not be accurately reflected by the martensite. Therefore, using common methods such as GROD (Grain Reference Orientation Deviation) or GOS (Grain Orientation Spread) to determine recrystallization seems incorrect.
(The above issues mainly concern grains with sizes below 500 nm); my understanding may not be comprehensive or have errors, are there any relevant studies to recommend?
I see the most problematic part is that martensite grains are never perfeclty in K-S or N-W so when you do PAG reconstruction it will result in austenite grains with misorinetations or in one average orientation in case your software avareges orietnation inside PAG. When deformed austenite grain transforms into martensite the resulting martensite will be further from K-S or N-W than non deformed austenite grain. Becasue the assumption is OR from perfect single crystal parent and in this case it would be deformed single crystal.
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