Microstructure observation and texture evaluation of low alloy steel after dynamic ferrite transformation

Xu, P. G.   ; Tomota, Yo*; Gong, W.*; Vogel, S. C.*; Suzuki, Hiroshi  ; Suzuki, Tetsuya*

Our neutron diffraction study of deformation induced ferrite transformation showed that at the lower temperature in the dual phase region, the evident change in grain orientation density of ferrite was found between large strain hot compression and small strain hot compression. In this study, the microstructure observation showed that the dynamic recrystallization occurred during the hot compression. The texture evaluation showed a strong (001)[uvw] component together with a (111)[uvw] fiber, which is consistent with our previous neutron analysis on grain orientation density. At 913K in the dual phase region, the large deformation resulted into coarse-fine mixed microstructure. The coarse grains were related to the untransformed austenite while the fine grains were partially related to the dynamic transformation of ferrite and partially related to the dynamic recrystallization of ferrite. It suggested that the dynamic ferrite transformation was orientation-dependent.