Intragranular nucleation of austenite

Serdar Atamert*, Julia E. King

*Corresponding author for this work

    Research output: Contribution to journalArticle

    Abstract

    The mechanism of intragranular nucleation of austenite in a duplex stainless steel (Fe-23.1 Cr-6.1 Ni-3.1 Mo-O.165 N-0.017 C, wt.%) weld metal and heat-affected zone (HAZ) has been examined. In the weld metal the acicular austenite is found to nucleate intragranularly on inclusions and subsequent plates form sympathetically resulting in a fine interlocked microstructure. Austenite plates adopt the Kurdjumov-Sachs orientation relationship with the ferrite matrix and grow with diffusion-controlled mechanism as evident from partitioning of substitutional alloying elements. At least one set of fine intrinsic dislocations on the austenite/ferrite interphase interfaces is observed suggesting that the boundaries are semi-coherent. The high cooling rates involved in the HAZ result in a supersaturated ferrite matrix where precipitation of intragranular austenite occurs as a result of reheating associated with subsequent passes. Austenite particles in the HAZ nucleate preferentially away from gain boundary austenite allotriomorphs indicating that intragranular precipitation is favoured by the supersaturated matrix.

    Original languageEnglish
    Pages (from-to)230-239
    Number of pages10
    JournalZeitschrift für Metallkunde
    Volume82
    Issue number3
    Publication statusPublished - 1 Mar 1991

    Keywords

    • precipitation metallography
    • stainless steel
    • welds
    • aurami equation
    • austenite ferrite interphase interfaces
    • austenite nucleation
    • duplex stainless steels
    • intragranular nucleation
    • Kurdjumov Sachs orientation
    • iron and steel metallography
    • heat affected zone

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  • Cite this

    Atamert, S., & King, J. E. (1991). Intragranular nucleation of austenite. Zeitschrift für Metallkunde, 82(3), 230-239.