Three-dimensional analysis of the precipitation behavior of 18Cr-9Ni-3Cu-Nb-N steel at 973 K
Three-dimensional analysis of the precipitation behavior of 18Cr-9Ni-3Cu-Nb-N steel at 973 K
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18Cr-9Ni-3Cu-Nb-N钢在973 K时析出行为的三维分析
DOI：
10.1016/j.scriptamat.2021.113904
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发表时间：
2021
影响因子：
6
通讯作者：
Kimura Kazuhiro
中科院分区：
文献类型：
--
作者：
Hatakeyama Tomotaka;Sawada Kota;Hara Toru;Sekido Kaoru;Kimura Kazuhiro
通过观察蠕变试样在973K下50214.3 h后断裂的夹持部，探讨了18Cr9Ni3CuNb-N钢在蠕变过程中的组织演变。结果表明，σ相的粗化导致M23C6相在晶界的贫化和铜相在σ相界面处的聚集。这些与σ相形成有关的显微组织变化是由于M23C6相的晶界析出强化和σ相周围的铜相的析出强化的贡献降低而导致长期蠕变过早失效的原因。
Microstructure development of 18Cr–9Ni–3Cu–Nb–N steel during creep was discussed by observing the grip portion of the crept specimen that ruptured after 50214.3 h at 973 K. Focused ion beam-scanning electron microscopy (FIB-SEM) serial sectioning and image processing with machine learning were combined for the three-dimensional visualization of the precipitation behavior of the steel. It was revealed that coarsening of σ phase induce the depletion of M23C6phase on the grain boundary and aggregation of Cu phase at the interface between the σ phase and the matrix. These microstructural changes related to the σ phase formation were suggested to cause premature failure in the longer-term creep due to the reduced contribution of grain boundary precipitation strengthening by M23C6phase and precipitation strengthening by Cu phase around the σ phase.