Decomposition of austenite in Fe-25Cr-1N alloy produced by solution nitriding

Toshihiro Tsuchiyma, N. Hirakawa, N. Nakada, S. Takaki

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    2 Citations (Scopus)

    Abstract

    The nickel-free austenitic stainless steel produced by solution nitriding (Fe-25%Cr-1%N alloy) was subjected to isothermal heat treatment, and then the microstructure formed through the decomposition of austenite was investigated in terms of the morphology of eutectoid structure and the size of eutectoid block. On the isothermal heat treatment at 873K-1223K for the solution-nitrided steel, the austenite decomposed to eutectoid structure composed of ferrite and Cr 2N nitride. This transformation could be completely finished after long time heat treatment in the above temperature range. The nose temperature of T.T.T. curve was around 1173K, and the time to start the eutectoid transformation was only 100-200s. The eutectoid structure was formed mainly along austenite grain boundaries and then grew into the untransformed austenite region. Finally, the austenite was completely decomposed into ferrite and Cr2N nitride. As a result of OIM observation for the specimen after isothermal heat treatment, the eutectoid structure was found to be divided into small-sized ferrite blocks, in which lamellar Cr2N plates were finely distributed. The block size and the mean ferrite path of eutectoid structure were decreased with lowering the heat treatment temperature. In the 873K heat-treated material, these values were estimated at 20 microns and 0.1 microns, respectively.

    Original languageEnglish
    Title of host publicationSupplement to THERMEC 2006, 5th International Conference on Processing and Manufacturing of Advanced Materials, THERMEC 2006
    Pages4950-4955
    Number of pages6
    Volume539-543
    EditionPART 5
    Publication statusPublished - 2007
    Event5th International Conference on Processing and Manufacturing of Advanced Materials - THERMEC'2006 - Vancouver, Canada
    Duration: Jul 4 2006Jul 8 2006

    Publication series

    NameMaterials Science Forum
    NumberPART 5
    Volume539-543
    ISSN (Print)02555476

    Other

    Other5th International Conference on Processing and Manufacturing of Advanced Materials - THERMEC'2006
    Country/TerritoryCanada
    CityVancouver
    Period7/4/067/8/06

    All Science Journal Classification (ASJC) codes

    • Materials Science(all)
    • Condensed Matter Physics
    • Mechanics of Materials
    • Mechanical Engineering

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