Heat Treatment of Metals ›› 2021, Vol. 46 ›› Issue (7): 13-17.DOI: 10.13251/j.issn.0254-6051.2021.07.003

• MICROSTRUCTURE AND PROPERTIES • Previous Articles     Next Articles

Influence of cold tensile pre-deformation and heat treatment on grain boundary characteristics of Hastelloy C-276 alloy

Liu Yian, Zhang Xiaoyu, Sun Huanying, Pang Guoxing, Wu Wei   

  1. School of Materials Engineering, North China Institute of Aerospace Engineering, Langfang Hebei 065000, China
  • Received:2021-02-24 Online:2021-07-25 Published:2021-12-10

Abstract: Hastelloy C-276 alloy was cold tensile deformed for 2%, 6%, 14%, 22%, 30% and 54%, respectively, then isothermally annealed at 1100 ℃ for 15 min and water cooled. Effects of deformation on the grain boundary characteristic distribution and on the grain size of the alloy were analyzed by EBSD technology. The results show that the total special grain boundary ratio shows a trend of decreasing first, then increasing and finally decreasing. When the deformation is up to 14%, the total proportion of special boundary reaches its peak point as to 64.8%; the Σ1 grain boundary proportion appears inflection point then tends to decrease, and the deformation storage energy can be released so the special grain boundary formation is promoted. At this time, the grain structure is in the initial stage of recrystallization. However, annealing under large deformation conditions is not conducive to increase the proportion of special grain boundaries. With the increase of grain size, the density of annealing twin decreases, so to optimize the grain size is conducive to the optimization of grain boundary character distribution.

Key words: cold deformation, heat treatment, annealing twin, grain boundary character distribution(GBCD), twin density

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