Dynamic Recrystallization of Austenite in Ni-30 Pct Fe Model Alloy: Microstructure and Texture Evolution
- 589 Downloads
The microstructure and crystallographic texture development in an austenitic Ni-30 pct Fe model alloy was investigated within the dynamic recrystallization (DRX) regime using hot torsion testing. The prominent DRX nucleation mechanism was strain-induced grain boundary migration accompanied by the formation of large-angle sub-boundaries and annealing twins. The increase in DRX volume fraction occurred through the formation of multiple twinning chains. With increasing strain, the pre-existing Σ3 twin boundaries became gradually converted to general boundaries capable of acting as potent DRX nucleation sites. The texture characteristics of deformed grains resulted from the preferred consumption of high Taylor factor components by new recrystallized grains. Similarly, the texture of DRX grains was dominated by low Taylor factor components as a result of their lower consumption rate during the DRX process. The substructure of deformed grains was characterized by “organized,” banded subgrain arrangements, while that of the DRX grains displayed “random,” more equiaxed subgrain/cell configurations.
This research was supported by grants through the Australian Research Council including an ARC Federation Fellowship (PDH). The authors also thank Dr. Y. Adachi for provision of the facilities to perform a portion of the current EBSD examination.
- 4.F.J. Humphreys and M. Hatherly: Recrystallization and Related Annealing Phenomena, 2nd ed., Pergamon, Oxford, United Kingdom, 1996.Google Scholar
- 19.P.D. Hodgson, D.C. Collinson, and B. Perrett: Proc. Int. Symp. on Physical Simulation, NRIM, Tsukuba, Japan, 1997, pp. 219–39.Google Scholar
- 20.D.S. Fields and A.W. Backofen: Proc. American Society of Testing Materials, 1957, vol. 75, pp. 1259–72.Google Scholar
- 22.H.J. Bunge: Texture Analysis in Materials Science: Mathematical Methods, Butterworth and Co., London, 1982.Google Scholar
- 23.V. Randle and O. Engler: Introduction to Texture Analysis: Macrotexture, Microtexture and Orientation Mapping, Gordon and Breach Science Publishers, Amsterdam, 2000.Google Scholar
- 26.P.J. Sah, C.J. Richardson, and C.M. Sellars: Met. Sci., 1974, vol. 8, pp. 325–31.Google Scholar
- 33.L. Blaz, T. Sakai, and J.J. Jonas: Met. Sci., 1983, vol. 17, pp. 609–16.Google Scholar
- 37.H.K.D.H. Bhadeshia: Worked Examples in the Geometry of Crystals, The Institute of Metals, London, 2001, pp. 41–43.Google Scholar
- 40.L. Priester: Mater. Sci. Eng. A, 2001, vols. 309–310, pp. 430–39.Google Scholar