Study of radiation-induced amorphization of M23C6 in RAFM steels under iron irradiations
Study of radiation-induced amorphization of M23C6 in RAFM steels under iron irradiations
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DOI：
10.1016/j.jnucmat.2020.152088
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发表时间：
2020-05-01
影响因子：
3.1
通讯作者：
Abe, Hiroaki
中科院分区：
文献类型：
--
作者：
Kano, Sho;Yang, Huilong;Abe, Hiroaki
MX和M23 C6颗粒的形成改善了低活化铁素体/马氏体钢（RAFM）的机械性能，如蠕变、热老化和耐辐照性。然而，众所周知，这些粒子在辐照下是不稳定的。本研究的目的是澄清F82 H钢中M23 C6的辐射诱导非晶化（RIA）的细节。研究了M_（23）C_6在较宽辐照温度范围内的不稳定性。系统地研究了不同离子束能量（2.8，3.7，6.4和10.5MeV）下，在773 K ~ 773 K温度范围内的离子束流场分布。本研究中使用了两种类型的材料，F82 H及其模型合金（F8）。通过对辐照前后样品的透射电镜观察和选区电子衍射分析，评价放射免疫反应的发生，并对样品的化学成分进行分析，揭示原子位移/扩散与放射免疫反应的可能关系。在低于598 K的温度下的铁照射的情况下，观察到的颗粒，由非晶边缘相和内部的结晶核心的双层对比度。在623 K辐照的F82 H样品中，有类似的粒子存活，在F8样品中未观察到放射免疫分析。据此，估算了放射免疫分析的临界温度为623-673 K.由于M23 C6的熔化温度（T-m）约为2173 K，因此临界温度对应于近似0.29 T-m。在573-623 K范围内，随着辐照温度的升高，颗粒的Fe/Cr比逐渐降低。这种行为定性地解释了非晶相的形成。阐明了可以通过Fe/Cr比值的变化来评价M23 C6颗粒放射免疫分析的发生。(c)2020爱思唯尔B. V.保留所有权利。
The mechanical properties of reduced activation ferritic/martensitic steels (RAFMs) such as creep, thermal aging, and irradiation resistance are improved by the formation of MX and M23C6 particles. However, it is well known that these particles are unstable under irradiation. The purpose of the present study is to clarify the details of the radiation-induced amorphization (RIA) of M23C6 in F82H steels. The instability behavior of M23C6 under a wide range of irradiation temperatures from R.T. to 773 K and various ion beam energies (2.8, 3.7, 6.4 and 10.5 MeV) was systematically investigated. Two types of materials, F82H and its model alloy (F8), were utilized in this study. TEM observation and selected area electron diffraction analysis before and after irradiation were conducted to evaluate the occurrence of RIA, and the chemical composition was analyzed to reveal the possible relation between atom displacement/diffusion and RIA. In the case of the iron irradiation at the temperature below 598 K, a bilayer contrast of the particle, consisting of an amorphous-rim phase and inner crystalline core, was observed. Similar particle survived in the irradiated F82H at the temperature of 623 K, the RIA was not observed in the F8 specimen. Consequently, the critical temperature of RIA was estimated as 623-673 K. Since the melting temperature (T-m) of M23C6 is approximately 2173 K, the critical temperature corresponds to similar to 0.29 T-m. From the STEM-EDS analysis, the Fe/Cr ratio of the particle decreased with increasing irradiation temperature in the range of 573-623 K. This behavior was qualitatively explained by the formation of the amorphous phase. It is clarified that the occurrence of the RIA of M23C6 particle can be evaluated by the variation of Fe/Cr ratio. (c) 2020 Elsevier B.V. All rights reserved.