Characterization of solidified melt among materials of UO2 fuel and B4C control blade
Characterization of solidified melt among materials of UO2 fuel and B4C control blade
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UO2燃料与B4C控制叶片材料凝固熔体表征
DOI：
10.1080/00223131.2014.912567
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发表时间：
2014
影响因子：
1.2
通讯作者：
N. Shirasu
中科院分区：
文献类型：
--
作者：
M. Takano;T. Nishi;N. Shirasu
为了预测福岛第一核电站堆芯凝固熔体中的基本相关系，通过电弧熔炼制备了各种堆芯材料[B4 C、不锈钢、Zr、ZrO 2、（U，Zr）O2]的凝固熔体样品。通过X射线衍射、显微镜和元素分析确定了样品的物相和组成。在不同的组成下，形成的唯一氧化物相是（U，Zr）O2。退火后，稳定的金属相是Fe-Cr-Ni合金和Fe_2Zr型（Fe，Cr，Ni）_2（Zr，U）金属间化合物。硼化物ZrB_2和Fe_2B型（Fe，Cr，Ni）_2B在金属部分中凝固。在Ar-0.1%O_2气氛下1773 K退火，合金中U和Zr以及ZrB_2被氧化，金属部分以（Fe，Cr，Ni）_2B和Fe-Cr-Ni合金为主。金属部分的实验相关系与简化的B_4C-Fe-Zr系平衡相的热力学估算相吻合。熔体中的金属Zr含量被认为是确定相关系的关键因素。作为基本的机械性能，测量了每个相的显微硬度。硼化物，特别是ZrB 2，显示出比任何其他氧化物或金属相明显更高的硬度。
To predict the fundamental phase relationships in the solidified core melt of the Fukushima Daiichi Nuclear Power Plant, solidified melt samples of the various core materials [B4C, stainless steel, Zr, ZrO2, (U,Zr)O2] were prepared by arc melting. Phases and compositions in the samples were determined by means of X-ray diffraction, microscopy, and elemental analysis. With various compositions, the only oxide phase formed was (U,Zr)O2. After annealing, the stable metallic phases were an Fe-Cr-Ni alloy and an Fe2Zr-type (Fe,Cr,Ni)2(Zr,U) intermetallic compound. The borides, ZrB2 and Fe2B-type (Fe,Cr,Ni)2B, were solidified in the metallic part. Annealing at 1773 K under an oxidizing atmosphere (Ar-0.1%O2) resulted in the oxidation of U and Zr in the alloy and in ZrB2, and consequently the (Fe,Cr,Ni)2B and Fe-Cr-Ni alloy became dominant in the metallic part. The experimental phase relationships in the metallic part agreed reasonably with the thermodynamic evaluation of equilibrium phases in a simplified B4C–Fe–Zr system. The metallic Zr content in the melt was found to be a key factor in determining the phase relationships. As a basic mechanical property, the microhardness of each phase was measured. The borides, especially ZrB2, showed notably higher hardness than any other oxide or metallic phases.