Galling-resistant Co-free hardfacings for light water reactors

磨损或粘着磨损是一种发生在阀门配合面等部位的现象。抗剥落材料，例如使用钴铬合金基体的钨铬钴合金，该基体具有高比例的碳化物沉淀物，可提供坚硬的非粘性区域覆盖。不幸的是，磨损碎片在反应堆堆芯中活化，引起操作员暴露挑战，从而促进了无钴硬面的开发。了解这些耐腐蚀的铁基硬面的行为是一个表征挑战，需要磨损超越其传统的学科家在机械工程。对于提出的粉末冶金路线，理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，特别是应力引起的转变和腐蚀尺度，需要进一步的（S）TEM为基础的表征和潜在的，轻元素的表面化学，如通过西姆斯和/或原子探针断层扫描。

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.