The formation mechanism, growth, and effect on the mechanical properties of precipitate free zones in the alumina-forming austenitic stainless steel Fe–20Cr–30Ni–2Nb–5Al during creep
The formation mechanism, growth, and effect on the mechanical properties of precipitate free zones in the alumina-forming austenitic stainless steel Fe–20Cr–30Ni–2Nb–5Al during creep
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DOI：
10.1016/j.msea.2021.141561
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发表时间：
2021-07
期刊：
影响因子：
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通讯作者：
A. Peterson;I. Baker
中科院分区：
文献类型：
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作者：
A. Peterson;I. Baker
用扫描电子显微镜和X射线能谱研究了Al_2O_3奥氏体不锈钢Fe-20Cr-30Ni-2Nb-5Al蠕变过程中L12无沉淀区的形成和长大机制。由于镍和铝的耗尽，L12析出物溶解，形成了PFZ。直到晶界被Laves相和足够大的B2析出物覆盖到足以耗尽周围的镍和铝的晶界之前，PFZ几乎没有长大。这导致L12析出物的溶解。此外，在长蠕变时间下观察到的PFZ中的微裂纹表明，PFZ最终是组织中最薄弱的点，断裂是从那里开始的。
The mechanisms of formation and growth of L12precipitate-free zones (PFZs) in the alumina-forming austenitic stainless steel Fe–20Cr–30Ni–2Nb–5Al during creep were studied using scanning electron microscopy and energy dispersive x-ray spectroscopy. The PFZs formed following the dissolution of L12precipitates due to depletion of nickel and aluminum. Little PFZ growth occurred until the grain boundaries were substantially covered by Laves phase and B2 precipitates large enough to deplete the surrounding grain of nickel and aluminum. This resulted in the dissolution of the L12precipitates. Additionally, micro-cracks observed in the PFZ at long creep times suggest that the PFZ is ultimately the weakest point in the microstructure, and that fracture initiates there.