Understanding the materials performance of additive manufactured stainless steel components in high temperature water

了解增材制造不锈钢部件在高温水中的材料性能

• 批准号: 2879262
• 金额: --
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2879262
• 关键词: Understanding; materials; performance; additive; manufactured

Austenitic stainless steels and Ni base alloys are extensively used in the primary circuit internals of pressurized water reactors (PWR) due to their high corrosion resistance properties. However, it is also well known that materials processing can have a strong impact on the susceptibility to stress corrosion cracking (SCC) of these materials when exposed in high temperature aqueous environment water coolant under active loading. Historically, components have been manufactured via conventional manufacturing routes, such as forging and welding; however, there is the desire to produce near net shape components via additive manufacturing thanks to the reduce machining costs, more agile manufacturing, and shorter lead times. However, there is currently insufficient knowledge on the impact of the metallurgical quality of the material produced by such processes on the materials performance. It is critical, therefore, to have a fundamental understanding of the relationship between manufacturing via modern near-to-net-shape manufacturing technologies, such as laser powder bed fusion, so that potential degradation caused by changes to current manufacturing practices can be judged. This, in turn, requires a scientifically-based understanding of the various underlying mechanisms influencing/controlling the environmental degradation and their linking to the end effects.SCC is one of the most insidious forms of materials degradation and its initiation behaviour in as manufactured components are major technical challenges. Although the SCC performance of stainless steels, Ni-base alloys in light water reactors environments has been studied extensively, the SCC data are not available for components produced using near-net-shape technologies. The overall aim of this project is to characterise the microstructure of additively manufactured (AM) stainless steels produced via laser powder bed fusion, and compare the mechanical properties (tensile strength, fracture toughness) and susceptibility to environmentally assisted cracking (EAC) of material in the three conditions of interest: forged, AM and heat treated. The secondary aim is to develop an understanding of the processing-microstructure-mechanical property relationships at work, and hence suggest process alterations to optimise material performance.

奥氏体不锈钢和NI碱基合金由于其高腐蚀性特性而广泛用于加压水反应堆（PWR）的原始电路内部。但是，众所周知，当在高温水中，在主动载荷下暴露于高温水性环境冷却液时，材料加工对这些材料的应力腐蚀破裂（SCC）的敏感性有很大影响。从历史上看，组件是通过常规制造路线（例如锻造和焊接）制造的。但是，由于加工成本降低，敏捷制造和较短的交货时间，人们希望通过添加剂制造生产近网状组件。但是，目前对此类过程产生的材料冶金质量的影响不足。因此，至关重要的是要通过现代的接近网状制造技术（例如激光粉床融合）对制造之间的关系有基本的了解，以便可以判断由于当前制造实践的变化而导致的潜在退化。反过来，这需要基于科学的理解，对影响/控制环境下降的各种潜在机制及其与最终效应的联系。SCC是最阴险的材料退化形式之一及其在制造成分中的启动行为是主要的技术挑战。尽管已广泛研究了轻水反应堆环境中不锈钢的SCC性能，但在使用近网状技术生产的组件中，SCC数据已被广泛研究。该项目的总体目的是表征通过激光粉末床融合产生的添加性制造（AM）不锈钢的微观结构，并比较机械性能（拉伸强度，断裂韧性）和对环境辅助裂纹（EAC）的易感性（EAC）在三种情况下的材料中的材料（EAC），在感兴趣的三种条件下：已锻造，AM和热处理。第二个目的是建立对工作中处理 - 微观结构机械性属性关系的理解，因此建议进行过程更改以优化材料性能。