Galling-resistant Co-free hardfacings for light water reactors

磨损或粘着磨损是一种现象，例如发生在阀门的配合表面。耐磨损材料，如使用Co-Cr基体的钨铬钴合金，具有高含量的碳化物沉淀，提供坚硬，不粘接的面积覆盖。不幸的是，磨损碎屑在堆芯中激活，给操作人员带来了暴露挑战，推动了无co堆焊的发展。了解这些耐腐蚀铁基堆焊材料的性能是一项表征挑战，这超出了机械工程的传统学科范围。对于提出的粉末冶金路线，了解相冶金是第一个挑战，需要x射线衍射和协同EDX - ebsd相表征。然后了解磨损行为，特别是应力诱导的转变和腐蚀尺度，需要进一步的(S) tem表征，并可能通过SIMS和/或原子探针断层扫描等轻元素的表面化学。

Galling, or adhesive wear, is a phenomenon that occurs, for example, in the mating surfaces of valves. Galling-resistant materials such as Stellites using a Co-Cr matrix with a high fraction of carbide precipitates that provide hard, non-adhesive areal coverage. Unfortuantely, the wear debris activates in the reactor core, giving rise to an operator exposure challenge, moptivating the development of Co-free hardfacings. Understanding how these corrosion-resistant iron-based hardfacings behave is a characterisation challenge that takes galling beyond its traditional disciplinary home in Mechanical Engineering. With the proposed powder metallurgy routes, understanding the phase metallurgy is the first challenge, requiring X-ray diffraction and synergistic EDX - EBSD-based phase characterisation. Then understanding the galling behaviour and particularly the stress-induced transformations and corrosion scales requires further (S)TEM-based characterisation and potentially, surface chemistry on light elements such as through SIMS and/or atom probe tomography.