On the microstructural evolution in 12% Cr turbine steel during low cycle fatigue at elevated temperature
On the microstructural evolution in 12% Cr turbine steel during low cycle fatigue at elevated temperature
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DOI：
10.1016/j.msea.2019.138864
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发表时间：
2020-01
期刊：
影响因子：
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通讯作者：
Yaroslav Rae;X. Guo;A. Benaarbia;N. Neate;Wei Sun
中科院分区：
文献类型：
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作者：
Yaroslav Rae;X. Guo;A. Benaarbia;N. Neate;Wei Sun
为了更好地了解变形和循环软化的物理过程，对12%Cr马氏体不锈钢FV566进行了高温应变控制循环试验。温度的升高增加了材料的循环寿命、软化速率和粘性应力大小。随着停留时间的增加，材料的降解速度加快。用扫描电子显微镜、背散射电子衍射和透射电子显微镜研究了合金的组织变化和主要变形机制。结果表明，板条组织逐渐粗化，板条组织向细小的等轴亚晶转变，块状和块状组织中的取向不均角发展直至材料破坏。软化行为归因于低能结构中位错的相互湮没和残余位错的重排。
In order to better understand the physical process of deformation and cyclic softening a 12% Cr martensitic stainless steel FV566 has been cyclically tested at high temperature in strain control. Increase in temperature was found to increase the cyclic life, softening rate and viscous stress magnitude. An increase in the dwell time led to the acceleration of the material degradation. The microstructure changes and dominating deformation mechanisms were investigated by means of scanning electron microscopy, electron backscatter diffraction and transmission electron microscopy. The results have revealed a gradual sub-grain coarsening, transformation of lath structure into fine equiaxed subgrains, and misorientation angle development in blocks and packets until material failure. The softening behaviour was attributed to the mutual annihilation of the dislocations and rearrangement of the residual dislocation in the low energy structures.