锻压技术

热成形工艺对GH5188钴基高温合金薄板晶界特征分布的影响

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

作者：薛润东1 王成猛2 万润2

单位：1.北京科技大学新材料技术研究院 2.北京科技大学材料科学与工程学院

关键词：GH5188钴基高温合金温度变形量 ∑3晶界晶界特征分布

分类号：TG132.3

出版年,卷(期):页码：2024,49(4):68-75

摘要：

采用热处理和热模拟试验探究温度与变形量对GH5188钴基高温合金薄板晶界特征分布的影响，通过电子背散射衍射对不同热成形工艺下的GH5188钴基高温合金进行分析表征，探索优化GH5188钴基高温合金晶界特征分布的工艺。研究表明，热处理温度为1050 ℃时重合位置点阵（CSL）晶界比例最大，此时样品中产生大量∑3晶界及其他低∑CSL晶界，且有汇聚成晶界团簇的趋势。CSL晶界的数量随着变形量的增大而减少，小角度晶界比例随之增加，孪晶趋向于沿纵向排列。热成形后，∑3晶界比例峰值所对应的温度由1050 ℃下降至1000 ℃，热成形条件为1000 ℃、10%变形量时，CSL晶界比例最大，达到43%。∑3晶界占CSL晶界总体的70%以上，其特征分布是晶界优化的关键。

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.

基金项目：

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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