STP1175: Microstructural Studies in Fast Reactor Irradiated FV448 Ferritic-Martensitic Alloy Plate and Weldment

    Morgan, TS
    Research student and Professor, Institute of Polymer Technology and Materials Engineering, University of Technology, Loughborough, Leicestershire

    Little, EA
    Senior Scientist, Materials and Chemistry Division, Harwell Laboratory, Oxfordshire,

    Faulkner, RG
    Research student and Professor, Institute of Polymer Technology and Materials Engineering, University of Technology, Loughborough, Leicestershire

    Pages: 15    Published: Jan 1994


    Abstract

    The microstructure of an off-normal 12%Cr FV448-grade ferritic-martensitic weldment with 4.7 wt.% nickel addition has been compared with that of parent plate following fast reactor irradiation at 465°C to damage levels in the range 28–46 dpa. The fully martensitic weld metal exhibits instability under irradiation and transforms to a duplex austenitic/-martensitic structure with high void swelling in the austenite. Irradiation-induced precipitation differs between weldment and parent plate. M6X and G-phase are dominant phases formed in the plate; however, large δ-ferrite grains in the heat-affected zone contain only G-phase. Differences in precipitation in FV448 observed in earlier studies can be rationalized in terms of parameters which influence radiation-induced segregation.

    Keywords:

    ferritic-martensitic steels, weldments, irradiation-induced precipitation, fast reactors


    Paper ID: STP23961S

    Committee/Subcommittee: E10.02

    DOI: 10.1520/STP23961S


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