Microstructural evolution of an aged Ni-based superalloy under two-stage hot compression with different strain rates
Microstructural evolution of an aged Ni-based superalloy under two-stage hot compression with different strain rates
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不同应变率两阶段热压缩时效镍基高温合金显微组织演化
DOI：
10.1016/j.matdes.2016.09.007
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发表时间：
2016-12-05
影响因子：
8.4
通讯作者：
Yuan, Wu-Quan
中科院分区：
文献类型：
--
作者：
Li, Kuo-Kuo;Chen, Ming-Song;Yuan, Wu-Quan
研究了时效镍基高温合金在不同应变速率的两阶段热压缩变形下的显微组织演变。从应变率来看，热压缩试验包括恒定应变率和阶梯应变率两种。对于第一种类型，在整个热压缩过程中应变率保持恒定，而对于第二种类型，热压缩过程由两个阶段组成：I和II。此外，第一阶段的应变速率（0.01、0.1和1 s(-1)）大于第二阶段的应变速率（0.001 s(-1)）。研究发现，应变速率和第一阶段的应变极大地影响了阶梯应变速率热压缩变形的微观结构演化。在测试的应变速率和应变中，δ相的溶解速率和动态再结晶（DRX）体积分数均随着第一阶段应变速率的减小或应变的增加而增加。与恒定应变速率热变形相比，如果选择合适的第一阶段应变速率和应变，阶梯应变速率可以明显促进DRX行为和d相的溶解。这些发现可直接应用于高温合金部件的实际工业生产中。 (C) 2016 Elsevier Ltd. 保留所有权利。
The microstructural evolution of an aged Ni-based superalloy under two-stage hot compressive deformation with different strain rates is investigated. In terms of strain rate, the hot compressive tests include two types: constant and stepped strain rates. For the first type, the strain rate remains constant during thewhole hot compression, while for the second type, the hot compression process consists of two stages: I and II. Moreover, the strain rate of stage I (0.01, 0.1, and 1 s(-1)) is larger than that of stage II (0.001 s(-1)). It is found that the strain rate and strain of stage I greatly affect the microstructural evolution for the hot compressive deformation with stepped strain rates. In the tested strain rate and strain, both the dissolution rate of delta phase and the dynamic recrystallization (DRX) volume fraction increase with the decrease of strain rate or the increase of strain in stage I. Compared with the constant strain rate hot deformation, the stepped strain rates can obviously promote DRX behaviors and the dissolution of d phase if the appropriate strain rate and strain of stage I are chosen. These findings can be directly applied in the practical industrial production of superalloy components. (C) 2016 Elsevier Ltd. All rights reserved.