Mesoscale finite element phase field modelling of liquid lithium corrosion of steels

钢液锂腐蚀的介观有限元相场建模

• 批准号: 2764612
• 金额: --
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2764612
• 关键词: Mesoscale; finite; element; phase; field

Liquid lithium is a proposed coolant for the STEP fusion reactor because of its ability to remove heat efficiently, as a liquid metal, but with the added advantage that Li can breed tritium from neutron interactions. One of the proposed materials that the liquid lithium will be in contact with is grade P91 steels. These steels have been used extensively in the fossil fuels and nuclear industry and they have both reasonable corrosion/oxidation resistance due to the Cr present but more importantly have high creep strength at elevated temperatures required by STEP. P91 grades are ferritic-martensitic steels with a highly complex microstructure that contains a variety of both precipitates and inclusions. These are well known to influence the creep properties but are likely to have a role to play in the corrosion of the steel by liquid lithium. At Imperial we have recently been developing a model, within the finite element phase field method framework, that can generate polarisation curves similar to those observed experimentally during the measurements of corroding metals. These models will be developed to study single grain, bi-crystals and grains with a single second phase particle embedded, of the various types found in P91 steels, to assess which particles are critical in the presence of Li and control the corrosion behaviour of these steels. These models will be developed in parallel with the localised corrosion experiments that will take place at UKAEA of P91 steels in liquid lithium. The models once developed for simple cases will also attempt (subject to experimental data availability) to include the effect of radiation damage through hardening and potentially grain boundary chemical segregation effects in these steels on the corrosion behaviour in liquid Li.

液态锂是STEP聚变反应堆的拟议冷却剂，因为它能够有效地去除热量，作为液态金属，但具有额外的优势，Li可以从中子相互作用中增殖氚。其中一种与液态锂接触的材料是P91级钢。这些钢已被广泛用于化石燃料和核工业，并且由于存在Cr，它们具有合理的耐腐蚀性/抗氧化性，但更重要的是在STEP所需的高温下具有高蠕变强度。P91等级是铁素体-马氏体钢，具有高度复杂的微观结构，包含各种沉淀物和夹杂物。众所周知，这些影响蠕变性能，但可能在液态锂对钢的腐蚀中起作用。在帝国理工学院，我们最近一直在开发一种模型，在有限元相场法的框架内，可以产生类似于腐蚀金属测量过程中实验观察到的极化曲线。将开发这些模型来研究P91钢中发现的各种类型的单晶粒、双晶体和嵌入有单个第二相颗粒的晶粒，以评估哪些颗粒在Li存在下是关键的，并控制这些钢的腐蚀行为。这些模型将与将在UKAEA进行的P91钢在液态锂中的局部腐蚀实验并行开发。模型一旦开发的简单的情况下，也将尝试（实验数据的可用性），包括通过硬化和潜在的晶界化学偏析的影响，这些钢在液体锂的腐蚀行为的辐射损伤的影响。