Metallurgical And Materials Transactions A-Physical Metallurgy And Materials Science, cilt.53, sa.5, ss.1-17, 2022 (SCI-Expanded)
Evolution of crystallographic texture and local strains in different zones of a dual-phase steel
subjected to severe plastic deformation by friction stir process was examined by electron
backscatter diffraction technique. Misorientations, which were expressed by the values of grain
orientation spread and kernel average misorientation (KAM), increased from the thermomechanical affected zone (TMAZ) to pin-affected stir zone (PE-SZ). KAM maps showed that the
highest local strain appeared in the PE-SZ. Misorientation distributions were found to be
consistent with microhardness distributions in the processed region. The crystallographic
texture of base metal, heat-affected zone, and TMAZ was similar. Recrystallization and
deformation texture components were observed at stir zones, and recrystallization texture
components decreased drastically at PE-SZ. Rotated cube, goss and rotated goss texture
components were detected at PE-SZ. Rotated cube texture component indicates partial
recrystallization after plastic deformation. Shear texture components were determined using
shear direction (SD) as reference. Different shear texture components (111), (112), and (101) ||
SD were found in the processed region revealing the differences in material flow and plastic
deformation at each zone. Some other texture components were found to be resulting from
transformation of austenite into ferrite/martensite, by taking orientation relationship between
those parent and product phases. Taylor factor values of all zones were calculated in order to
understand the influence of texture on mechanical properties. The results indicate that
crystallographic texture has a minor influence on hardness compared to grain refinement and
dislocation density