Figure 4 shows the OAGBs with various degree of austenitic
overcooling, i.e., deformation temperature, indicating
a pancaked morphology. The grain boundary widths
of pancaked austenite are 32.9, 32.8, 34.4 and 33.8 μm
respectively, which correspond to the width of deformed
austenite under 40% reduction, i.e., 34.9 μm. The OAGBs
are smooth after deformation at 700°C (Fig. 4(a)). As
deformation temperature dropped to 650°C, the bowing out