Interaction of carbon-vacancy complex with minor alloying elements of ferritic steels
Interaction of carbon-vacancy complex with minor alloying elements of ferritic steels
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DOI：
10.1016/j.jnucmat.2014.03.031
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发表时间：
2014-08-01
影响因子：
3.1
通讯作者：
Van Neck, D.
中科院分区：
文献类型：
--
作者：
Bakaev, A.;Terentyev, D.;Van Neck, D.
在铁素体钢的体心立方中溶解的间隙碳与空位有很强的相互作用，在辐射诱导组织演变中起着重要的作用。辐照过程中碳-空位对的频繁形成和断裂既影响点缺陷团簇的积累动力学，又影响碳的空间分布。用从头算方法分析了核反应堆结构材料铁素体钢中典型的合金元素(Mn、Ni、Cu、Si、Cr和P)与碳-空位复合体的相互作用。结果表明，所有被考虑的溶质都形成稳定的三团簇，使总结合能增加0.2-0.3 eV。由于形成了能量有利的溶质-碳-空位三重态，空位/碳发射的离解能也增加了约0.2-0.3 eV，表明溶质提高了碳-空位复合体的热稳定性。发现碳-空位对与多个溶质团簇的缔合有利于镍、铜和磷的存在。根据成对相互作用数据和分析组成团簇原子的局域磁矩的变化，对溶质(S)-碳-空位络合物的能量稳定性进行了合理化。(C)2014爱思唯尔B.V.保留所有权利。
Interstitial carbon, dissolved in bcc matrix of ferritic steels, plays an important role in the evolution of radiation-induced microstructure since it exhibits strong interaction with vacancies. Frequent formation and break-up of carbon-vacancy pairs, occurring in the course of irradiation, affect both kinetics of the accumulation of point defect clusters and carbon spatial distribution. The interaction of typical alloying elements (Mn, Ni, Cu, Si, Cr and P) in ferritic steels used as structural materials in nuclear reactors with a carbon-vacancy complex is analyzed using ab initio techniques. It is found that all the considered solutes form stable triple clusters resulting in the increase of the total binding energy by 0.2-0.3 eV. As a result of the formation of energetically favourable solute-carbon-vacancy triplets, the dissociation energy for vacancy/carbon emission is also increased by similar to 0.2-0.3 eV, suggesting that the solutes enhance thermal stability of carbon-vacancy complex. Association of carbon-vacancy pairs with multiple solute clusters is found to be favorable for Ni, Cu and P. The energetic stability of solute(s)-carbon-vacancy complexes was rationalized on the basis of pairwise interaction data and by analyzing the variation of local magnetic moments on atoms constituting the clusters. (C) 2014 Elsevier B.V. All rights reserved.