Effect of initial orientation on the cold-rolling behavior of solidified columnar crystals in an Fe-36%Ni austenitic alloy

The cold rolling behavior of a solidified columnar-crystal specimen with the 001〈uv0〉 initial texture in an Fe-36%Ni austenitic (f.c.c.) alloy has been investigated. The rolled microstructure and the crystal rotation strongly depended on the initial orientation of columnar grains. 70% rolled microstructure of the initially (001)[100] oriented grains was composed of three kinds of deformed microstructures: the smoothly-etched matrix with the (001)[100] orientation, the wide deformation bands roughly parallel to the transverse direction (TD) with the (101)[101-] orientation and the narrow deformation bands parallel to the rolling direction (RD). The shear bands inclined by 30 deg from the rolling plane formed within the initially (001)[110] oriented grains, where the matrix regions rotated to the 113〈332〉 orientation. Each shear band was composed of many elongated cells whose width was less than 0.2 μm. The formation of each deformed microstructure was discussed in connection with the active slip systems.†Present address: Department of Materials Science and Engineering, Faculty of Engineering, Osaka University, Yamada-oka 2-1, Suita, Osaka, 565 Japan.‡Present address: Sumitomo Metal Industries Ltd, Hazaki-cho, Kashima-gun, Ibaragi, 314 Japan.§Present address: Nissan Motor Co. Ltd, Oppama, Yokosuka, Kanagawa, 273 Japan.