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.

液体锂是台阶融合反应堆的提议的冷却剂，因为它能够有效地作为液体金属去除热量，但具有额外的优势，即Li可以从中子相互作用中繁殖Tritium。液体锂将接触的提议材料之一是P91钢。这些钢已经在化石燃料和核工业中广泛使用，由于当前的CR，它们既具有合理的腐蚀/氧化耐药性，但更重要的是，在逐步要求的升高温度下具有很高的蠕变强度。 p91等级是铁素体 - 肌钢，具有高度复杂的微观结构，其中包含各种沉淀物和夹杂物。众所周知，这些会影响蠕变特性，但可能在液体锂对钢的腐蚀中起作用。在Imperial，我们最近在有限的元素相位方法框架内开发了一个模型，该模型可以生成与腐蚀金属测量过程中实验观察到的极化曲线相似的偏振曲线。这些模型将开发用于研究P91钢中各种类型的单个第二相粒子的单粒，双晶和晶粒，以评估在存在LI并控制这些钢的腐蚀行为的情况下哪些颗粒至关重要。这些模型将与将在液体锂中P91钢的UKAEA进行的局部腐蚀实验并行开发。曾经为简单情况开发的模型还将尝试（如果实验数据可用性），以包括通过硬化和潜在的晶界化学化学分离效应对辐射损伤的影响，这些钢对液体LI腐蚀行为。