b'FeCrAl Optimization and Corrosion ResultsPrincipal Investigator: Caleb MasseyTeam Members/Collaborators: Mackenzie Ridley, Yukinori Yamamoto, David HoelzerT his work involves optimiza- in alloy mechanical performance if tion of FeCrAl alloys ascompositional changes are pursued, nuclear reactor materials inand (3) autoclave testing to illustrate regard to both corrosion and irra- the effect of Cr content on the corro-diation responses. Historic FeCrAlsion performance of FeCrAl alloys alloys contain high Cr contents,in LWR environments. These three which leads to precipitation of angoals are critical to the state-of-the-alpha prime phase during bothart knowledge on the FeCrAl alloy thermal ageing and exposure tosystem because the model alloy C26M radiation, which can produce(Fe-12Cr-6Al wt%) was down-selected undesirable mechanical propertyprimarily based on factors such as effects. Oak Ridge National Labora- fabricability, high-temperature steam tory (ORNL) manufactured multipleoxidation performance, and to mini-FeCrAl alloys with variations in Crmize Fe-Cr phase separation during content from 12 wt. % to 17 wt. %irradiation and/or thermal ageing. while maintaining a constant AlThus, corrosion was not considered in content. The goal was to understandthis initial down-selection framework. the minimum Cr content thatConsequently, this work aims to fill would result in acceptable oxidethis critical gap regarding the effect of thicknesses after long term exposureCr on the performance of the FeCrAl at prototypic reactor conditions, andalloy system under normal operating how the varied Cr content impactedconditions, thereby pushing forward mechanical properties. Currentthis alloy concept as a potential progress shown here includes thedrop-in replacement for existing initial oxidation behavior of FeCrAlZr-based alloys and enhancing the alloys after exposure to hydrogensafety of the existing LWR fleet.water chemistry under light water reactor (LWR) conditions. High- Accomplishmentstemperature tensile testing wasMultiple FeCrAl alloys were forged at also performed to support FeCrAlORNL to assess the impacts of varied chemistry optimization. Cr content on oxidation and high-temperature mechanical perfor-Project Description: mances. The Al content in these alloys The technical objectives of thiswas maintained at 6 wt. % such that research include (1) the developmentthe impacts of varied Cr content could of FeCrAl alloys with systematicallybe best visualized during corrosion varied chemistries, (2) mechanicaltesting. Due to the dissolution of Cr testing to establish potential tradeoffsin boiling water reactor chemistries, 50 2023|AFC ACCOMPLISHMENTS'