Recrystallization of solidified columnar crystals in an Fe-36%Ni austenitic alloy

The recrystallization behavior of the 21 columnar grains in an Fe-36%Ni austenitic (f.c.c.) alloy during annealing at 973 K after 70% cold-rolling, whose rolling behavior had been studied in the coupled paper, has been studied with emphasis on the effect of the initial orientation. The recrystallization rate and the recrystallized grain size of the columnar-crystal specimen were hardly dependent on the initial orientation. This result is in contrast to that reported in the Fe-19%Cr (b.c.c.) columnar crystals. The reason for this difference was discussed in connection with the easiness of cross-slip in the two alloys. On the other hand, the orientation of recrystallized grains was dependent on the initial orientation. The columnar-crystal specimen showed the (001)〈310〉 recrystallization texture. The (001)〈310〉 recrystallized grains preferentially appeared from the shear bands which formed in the (001)[110] initially oriented columnar grains. TEM observation showed that some elongated cells within the shear bands have the (001)〈310〉 orientation in the as-rolled state.†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, Hazakicho, Kashima-gun, Ibaragi, 314 Japan.§Present address: Nissan Motor Co Ltd, Oppama, Yokosuka, Kanagawa, 273 Japan.