The dissolution behavior and kinetics of γ′ precipitates during solution treatment were investigated in an advanced powder metallurgy nickel-based superalloy FGH98. The microstructural evolutions were quantitatively characterized, and the dissolution kinetics were evaluated. The results show that due to the influence of precipitate size and element distribution, the dissolution rate of secondary γ′ precipitates was higher than that of large primary γ′ precipitates, but lower than that of small tertiary γ′ precipitates. With the increase of holding time, the area fractions of γ′ precipitates decreased and then gradually approached a thermodynamic equilibrium for all three heating temperatures. The dissolution kinetics of γ′ precipitates were quantitatively evaluated using the JMAK model. During the initial stage, the dissolution rate decreased rapidly with increasing holding time, and then, changed more slowly. The dissolution activation energy of γ′ precipitates increased with increasing holding time.

中文翻译：

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粉末冶金镍基高温合金固溶处理过程中γ′相的溶解行为和动力学

在先进的粉末冶金镍基高温合金FGH98中研究了固溶处理过程中γ '沉淀的溶解行为和动力学。定量表征了微观结构的演变，并评估了溶解动力学。结果表明，由于析出物尺寸和元素分布的影响，次生γ ′沉淀物的溶出速率高于较大的初生γ ′沉淀物，但低于较小的叔生γ ′。随着保持时间的增加，γ的面积分数'在所有三个加热温度下，沉淀物减少，然后逐渐达到热力学平衡。使用JMAK模型定量评估γ '沉淀物的溶解动力学。在初始阶段，溶出度随保持时间的增加而迅速下降，然后变化较慢。γ '沉淀的溶解活化能随保持时间的增加而增加。