Abstract—

The article discusses a model of the interaction between a liquid−metal coolant (Pb, Pb55Bi(e)) and a heat exchanger material (316L steel) in an SVBR-type nuclear reactor cooling device for the case in which the effect of liquid-metal embrittlement cannot be ignored. It is assumed that a crack propagates due to the penetration of the liquid-metal coolant into intergrain boundaries. The free energy of a wetted surface is calculated using the mean-field theory within the formalism of finite element analysis. Tensile stress S (MPa) is determined for the propagation of a crack 50 µm long from a defect in the form of a 0.15-mm scratch on the surface of the heat exchanger. The calculation is carried out for an operation temperature range of 900–1100 K, when the melt wets the steel. The values of \(S = 253{\kern 1pt} -{\kern 1pt} 358\) and \(210{\kern 1pt} -{\kern 1pt} 369\,\,~{\text{MPa}}\) have been obtained for the interaction of Pb55Bi melts and Pb with 316L steel, respectively. The calculation results mean that a heat exchanger with surface defects can be damaged due to the effect of liquid-metal embrittlement.

中文翻译：

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液态金属与反应堆钢相互作用的有限元模型

摘要-

本文讨论了 SVBR 型核反应堆冷却装置中液态金属冷却剂（Pb、Pb55Bi(e)）与热交换器材料（316L 钢）之间相互作用的模型，其中液体-金属冷却剂的影响金属脆化不容忽视。假设裂纹由于液态金属冷却剂渗透到晶界而扩展。润湿表面的自由能是使用有限元分析形式中的平均场理论计算的。拉伸应力S (MPa) 是根据热交换器表面 0.15 毫米划痕形式的缺陷传播 50 微米长的裂纹来确定的。计算是在熔体润湿钢时的操作温度范围 900–1100 K 下进行的。\(S = 253{\kern 1pt} -{\kern 1pt} 358\)和\(210{\kern 1pt} -{\kern 1pt} 369\,\,~{\text{MPa}}的值\)分别获得了 Pb55Bi 熔体和 Pb 与 316L 钢的相互作用。计算结果意味着具有表面缺陷的换热器可能会因液态金属脆化的影响而损坏。