You are being redirected because this document is part of your ASTM Compass® subscription.
    This document is part of your ASTM Compass® subscription.

    If you are an ASTM Compass Subscriber and this document is part of your subscription, you can access it for free at ASTM Compass

    Impact of Iron in M5TM6

    Published: 17 June 2014

      Format Pages Price  
    PDF (2.7M) 25 $25   ADD TO CART
    Complete Source PDF (120M) 1177 $265   ADD TO CART

    Cite this document

    X Add email address send
      .RIS For RefWorks, EndNote, ProCite, Reference Manager, Zoteo, and many others.   .DOCX For Microsoft Word


    To assess the effect of iron (Fe) content on the properties of M5™, several industrial-sized ingots with Fe content up to 1000 ppm and some smaller ingots with Fe up to 1300 ppm have been manufactured, tested, and investigated. The evolution of the microstructure with iron content has been both experimentally determined and theoretically assessed with thermodynamic computations, showing that iron in the investigated range has only a slight impact on the balance between the two classical second-phase precipitates observed in M5™: β-Nb and Laves phase. Moreover, it was found that the impact of iron on texture and mechanical properties, including thermal creep, is null. Out-of-pile autoclave corrosion tests show, on the one hand, that the iron content has no effect in 360°C primary water environment and little effect in 400°C–415°C steam. On the other hand, iron content in the range of 300 to 1000 ppm improves the resistance to corrosion induced by galvanic phenomena. This phenomenon has been reproduced out-of-pile in galvanic coupling tests in 360°C oxygenated water. In-pile, the corrosion resistance is equivalent, or even improved, under demanding conditions when the iron content is increased. There is no adverse effect of iron content on free growth kinetics and creep behavior. Under loss of cooling accident (LOCA) conditions, the increase in iron content has no significant impact on creep–burst resistance and ductility of the cladding. The high-temperature steam oxidation kinetics, quench behavior, and post-quench behavior of fresh and pre-hydrided materials are not affected. Finally, because of the low hydrogen pickup of M5™ in service, which is unchanged by increased iron content, the high performance of M5™ under reactivity-initiated accident (RIA) conditions is not impacted.


    alloy composition, corrosion, dimensional properties, second-phase precipitates, iron, M5™, creep, mechanical properties, cladding

    Author Information:

    Kaczorowski, D.
    Research Engineer, AREVA NP, Fuel, Lyon Cedex,

    Mardon, J. P.
    AREVA Fellow Expert, Lyon Cedex,

    Barberis, P.
    AREVA Fellow expert, AREVA/ CEZUS Research Center, Ugine Cedex,

    Hoffmann, P. B.
    Senior Expert, AREVA NP GmbH, Erlangen,

    Stevens, J.
    Research Engineer, AREVA Inc., OF70 Lynchburg, VA

    Committee/Subcommittee: B10.02

    DOI: 10.1520/STP154320120195