Texture Memory in Si-Mn and ODS Steels Observed In Situ by Pulsed Neutron and Synchrotron X-Ray Diffractions and Prediction by Double Kurdjumov-Sachs Relation: A Concept for Intense Variant Selection

Texture memory of Si-Mn and ODS steels has been explored via in situ neutron time-of-flight and synchrotron high-energy X-ray diffractions as well as texture prediction by the double Kurdjumov-Sachs relation. The two steels exhibited very different behaviors of the texture memory. Three behaviors were observed: (1) for Si-Mn steel, the moderate initial {111} texture reappeared after ferrite → austenite → ferrite transformation; (2) for ODS steel the strong initial \(\langle 110\rangle\)-fiber texture weakened significantly after ferrite → austenite → martensite transformation; (3) also the strong initial texture was significantly reinforced after ferrite → austenite → ferrite transformation, whereas the texture was greatly weakened during ferrite → austenite transformation. These texture changes can be thoroughly explained by the double Kurdjumov-Sachs relation. The intense texture development in the ODS steel is ascribed to a strong variant selection on the diffusional austenite → ferrite transformation, in which variants satisfying the double Kurdjumov-Sachs relation grow exponentially without conserving the volume of parent crystals.