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Effects of cold rolling on the precipitation and the morphology of δ-phase in Inconel 718 alloy

  • Yunpeng Mei (a1), Chenxi Liu (a1), Yongchang Liu (a1), Xiaosheng Zhou (a1), Liming Yu (a1), Chong Li (a1), Zongqing Ma (a1) and Yuan Huang (a1)...

To investigate the effects of cold rolling on the microstructure, the precipitation behavior and the morphology of δ-phase, Inconel 718 alloy samples with different cold rolling reductions were aged for different periods at temperatures range from 850 °C to 1000 °C. Detailed microstructural observations and quantitative measurements were conducted to characterize the evolution of the δ-phase during aging. The results show that the microstructure consists of large deformed grains as a result of a slow static recovery at the low aging temperatures (850 and 900 °C); whereas the austenite matrix is fully recrystallized at the high aging temperatures (950 and 1000 °C). It is also found that the amount of δ-phase and the number density of spherical δ-phase particles increase with the increase in the degree of cold rolling both at low and high aging temperatures. With respect to different microstructural changes for the cold-rolled samples at the low or the high aging temperatures, two distinct mechanisms have been, respectively, introduced to interpret the changes in the precipitation behavior and the appearance of δ-phase.

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Journal of Materials Research
  • ISSN: 0884-2914
  • EISSN: 2044-5326
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