Transactions of Materials and Heat Treatment

Title：Effects of hot forming process on grain boundary characteristic distribution of cobalt-base superalloy GH5188 sheet

Authors： Xue Rundong1 Wang Chengmeng2 Wan Run2

Unit： 1. Institute for Advanced Materials and Technology University of Science and Technology Beijing 2. School of Materials Science and Engineering University of Science and Technology Beijing

KeyWords： cobalt-base superalloy GH5188 temperature deformation amount ∑3 grain boundary grain boundary characteristic distribution

ClassificationCode：TG132.3

year,vol(issue):pagenumber：2024,49(4):68-75

Abstract：

The effects of temperature and deformation amount on the grain boundary characteristic distribution of cobalt-base superalloy GH5188 sheet were investigated by heat treatment and thermal simulation experiments, and the cobalt-base superalloy GH5188 under different hot forming processes was analyzed and characterized by electron backscatter diffraction (EBSD), in order to explore the process of optimizing the grain boundary characteristic distribution for cobalt-base superalloy GH5188. The research indicats that the grain boundary proportion coincident site lattice (CSL) is maximum at the heat treatment temperature of 1050 ℃, while a significant number of ∑3 grain boundaries and other low-∑CSL grain boundaries are generated, showing a tendency to aggregate into grain boundary clusters. The quantity of CSL grain boundaries decreases with the increasing of deformation amount, accompanied by an increase in the proportion of small-angle grain boundaries, and the twin crystal tends to align longitudinally. After hot forming, the temperature corresponding to the peak proportion of ∑3 grain boundaries decreases from 1050 ℃ to 1000 ℃. Under the hot forming conditions of 1000 ℃ and 10% deformation amount, the CSL grain boundaries proportion is maximum,reaching at 43%. The characteristic distribution of ∑3 grain boundaries is the key for the grain boundary optimization, which accounts for over 70% of the overall CSL grain boundaries.

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作者简介：薛润东 (1965-)，女，博士，高级工程师 E-mail：xrd@ustb.edu.cn

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