Diffusion-induced recrystallization was studied during the zincification of pure Fe and interstitial-free steel. A change in microstructure was also investigated, as a function of annealing temperatures ranging from 723 to 963K. Misorientations were measured by using the electron back-scattering diffraction technique. There was a considerable nucleation of fine grains of ferrite, on the substrate surfaces of couples which were annealed at temperatures of the order of 963K, leading to a fine-grained surface layer. The boundaries between the fine grains were regarded as being high-angle boundaries, since they were strongly micro-etched; with the possible formation of grooves. In contrast to the fine grains which formed at higher temperatures, sub-grains formed at temperatures of the order of 723K. The boundaries between sub-grains were regarded as being low-angle boundaries. However, the sum of the local misorientations along a particular scanning direction depended upon the direction. The largest variation in misorientation of the original grains, in which sub-grains caused by diffusion-induced recrystallization existed, often occurred along a scanning direction which was terminated by high-angle boundaries of the original grains at at least one of its ends. A smaller variation in misorientation was observed along a direction which was terminated by S or low-angle boundaries at both ends. It was suggested that the largest variation in misorientation led high-angle boundaries to be formed, with the possible formation of fine grains having high-angle boundaries.

Diffusion-Induced Recrystallization in Fe (Zn) System Characterized by EBSD Y.Adachi, A.Seki: Journal of the Japan Institute of Metals, 1998, 62[8], 754-60