EBSD and electron channeling study of anomalous slip in oligocrystals of high chromium ferritic stainless steel

•Deformed microstructures and slip patterns of bcc oligocrystals were investigated using EBSD and ECCI.•KAM was used to identify the activated slip planes and deformation patterns.•ECCI techniques was used to investigate the slip patterns and identify the type of dislocation.•The anomalous slip depends on the orientations of oligocrystals in ferritic steel. In the present study, electron backscatter diffraction (EBSD) and electron channeling contrast imaging (ECCI) techniques were applied to investigate the deformation pattern of coarse ferrite grains after being subjected to 3%, 6%, and 10% tensile deformation. Oligocrystals of Crofer® 22H ferritic steel were obtained as experimental material at 1075°C for 22min annealing. Using kernel average misorientation (KAM) mapping obtained from EBSD, possible slip planes are (110), (101), (12–1) and (32-1) in grain A; (0–11), (−101), (−112), (1–21) in grain B; and (0–11), (1–21) and (11–2) in grain C. Combining ECCI and EBSD techniques enables us to identify two a0[11¯1]/2 edge dislocations that occur on the (110)[1–11] and (32–1)[1–11] slip systems for grain A, thereby breaking down Schmid’s law.