Recrystallization Processing of Cold-Rolled Nickel

Abstract

We have examined the effects of isothermal annealing, at a variety of temperatures, and directional annealing, under a range of conditions, on both primary recrystallization and secondary recrystallization in 90% cold-rolled 99.5% nickel of two different textures. The initial texture is shown to influence the rolling texture and, hence, the results of subsequent annealing. It was found that one alloy showed a cube texture after primary recrystallization, underwent abnormal grain growth upon annealing at high temperatures, and could be directionally (secondary) recrystallized to give large columnar grains. In contrast, the other alloy produce a weak cube texture after primary recrystallization, showed only normal grain growth upon annealing at higher temperatures, and could not be directionally annealed to produce columnar grains. The implications of these results are discussed for producing columnar grains.

Experiments and simulations of directionally annealed ODS MA 754

“…This implies that a texture is required for columnar grains to form. In fact, as noted earlier, columnar grains can be produced in high-purity nickel by directional recrystallization, in the absence of particles, at the appropriate hot-zone velocities if the appropriate texture is present [35,36,[43][44][45]. In other words, particles are not necessary to produce a columnar grain structure, which is in agreement with the conclusion of Baloch and Bhadeshia [6].…”