Preliminary Analysis of the General Performance and Mechanical Behavior of Irradiated FeCrAl Base Alloys and Weldments

Technical Report · Fri Sep 30 00:00:00 EDT 2016

DOI:https://doi.org/10.2172/1328330· OSTI ID:1328330

Gussev, Maxim N. ^[1]; Field, Kevin G. ^[1]; Briggs, Samuel A. ^[1]; Yamamoto, Yukinori ^[1]

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1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

The iron-based, iron-chromium-aluminum (FeCrAl) alloys are promising, robust materials for deployment in current and future nuclear power plants. This class of alloys demonstrates excellent performance in a range of environments and conditions, including high-temperature steam (>1000°C). Furthermore, these alloys have the potential to have prolonged survival under loss-of-coolant accident (LOCA) conditions compared to the more traditional cladding materials that are either Zr-based alloys or austenitic steels. However, one of the issues associated with FeCrAl alloys is cracking during welding. The present project investigates the possibility of mitigating welding-induced cracking via alloying and precise structure control of the weldments; in the frame work of the project, several advanced alloys were developed and are being investigated prior to and after neutron irradiation to provide insight into the radiation tolerance and mechanical performance of the weldments. The present report provides preliminary results on the post-irradiation characterization and mechanical tests performed during United States Fiscal Year (FY) 2016. Chapter 1 provides a general introduction, and Chapter 2 describes the alloy compositions, welding procedure, specimen geometry and manufacturing parameters. Also, a brief discussion of the irradiation at the High Flux Isotope Reactor (HFIR) is provided. Chapter 3 is devoted to the analysis of mechanical tests performed at the hot cell facility; tensile curves and mechanical properties are discussed in detail focusing on the irradiation temperature. Limited fractography results are also presented and analyzed. The discussion highlights the limitations of the testing within a hot cell. Chapter 4 underlines the advantages of in-situ testing and discusses the preliminary results obtained with newly developed miniature specimens. Specimens were moved to the Low Activation Materials Development and Analysis (LAMDA) laboratory and prepared for mechanical tests. Tensile tests were conducted at LAMDA using a modern digital image correlation approach allowing for strain distribution analysis. Plastic strain initiation and necking are discussed in detail; a concept of strain rate maps is also introduced and discussed. Follow-on SEM-EBSD and FIBTEM analysis is planned.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). High Flux Isotope Reactor (HFIR)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE). Nuclear Energy Enabling Technologies (NEET) Program; USDOE Office of Science (SC), Basic Energy Sciences (BES)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1328330
• Report Number(s): ORNL/TM-2016/552; AF5810000; NEAF278; TRN: US1700345
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
WELDED JOINTS
IRON BASE ALLOYS
CHROMIUM ALLOYS
ALUMINIUM ALLOYS
TERNARY ALLOY SYSTEMS
MECHANICAL TESTS
WELDING
CRACKS
IRRADIATION
NEUTRONS
PERFORMANCE
STRAINS
DIAGRAMS
MECHANICAL PROPERTIES
STRAIN RATE
FRACTOGRAPHY
MANUFACTURING
MAPS
TENSILE PROPERTIES