Elemental partitioning and microstructural development in duplex stainless steel weld metal

S. Atamert, J.E. King

    Research output: Contribution to journalArticle

    Abstract


    A thermodynamic analysis which is capable of estimating the austenite/ferrite equilibria in duplex stainless steels has been carried out using the sublattice thermodynamic model. The partitioning of alloying elements between the austenite and ferrite phases has been calculated as a function of temperature. The results showed that chromium partitioning was not influenced significantly by the temperature. The molybdenum, on the other hand, was found to partition preferentially into ferrite phase as the temperature decreases. A strong partitioning of nickel into the austenite was observed to decrease gradually with increasing temperature. Among the alloying elements, average nitrogen concentration was found to have the most profound effect on the phase balance and the partitioning of nitrogen into the austenite. The partitioning coefficient of nitrogen (the ratio of the mole fraction of nitrogen in the austenite to that in the ferrite) was found to be as high as 7.0 around 1300 K. Consequently, the volume fraction of austenite was influenced by relatively small additions of nitrogen. The results are compared with the experimentally observed data in a duplex stainless steel weld metal in conjunction with the solid state δ → δ + γ phase transformation. Particular attention was given to the morphological instability of grain boundary austenite allotriomorphs. A compariso between the experimental results and calculations indicated that the instability associated with irregular austenite perturbations results from the high degree of undercooling. The results suggest that the model can be used successfully to understand the development of the microstructure in duplex stainless steel weld metals.
    Original languageEnglish
    Pages (from-to)273-285
    Number of pages13
    JournalActa Metallurgica et Materialia
    Volume39
    Issue number3
    DOIs
    Publication statusPublished - Mar 1991

    Fingerprint

    Austenite
    Welds
    Stainless steel
    Metals
    Ferrite
    Nitrogen
    Alloying elements
    Thermodynamics
    Temperature
    Undercooling
    Molybdenum
    Chromium
    Volume fraction
    Grain boundaries
    Phase transitions
    Nickel
    Microstructure

    Keywords

    • microstructure iron and steel metallography
    • microstructure stainless steel
    • elemental partioning
    • weld metal
    • duplex steel
    • welds

    Cite this

    @article{46fd6a9cd2c346e8bcb7f43062091547,
    title = "Elemental partitioning and microstructural development in duplex stainless steel weld metal",
    abstract = "A thermodynamic analysis which is capable of estimating the austenite/ferrite equilibria in duplex stainless steels has been carried out using the sublattice thermodynamic model. The partitioning of alloying elements between the austenite and ferrite phases has been calculated as a function of temperature. The results showed that chromium partitioning was not influenced significantly by the temperature. The molybdenum, on the other hand, was found to partition preferentially into ferrite phase as the temperature decreases. A strong partitioning of nickel into the austenite was observed to decrease gradually with increasing temperature. Among the alloying elements, average nitrogen concentration was found to have the most profound effect on the phase balance and the partitioning of nitrogen into the austenite. The partitioning coefficient of nitrogen (the ratio of the mole fraction of nitrogen in the austenite to that in the ferrite) was found to be as high as 7.0 around 1300 K. Consequently, the volume fraction of austenite was influenced by relatively small additions of nitrogen. The results are compared with the experimentally observed data in a duplex stainless steel weld metal in conjunction with the solid state δ → δ + γ phase transformation. Particular attention was given to the morphological instability of grain boundary austenite allotriomorphs. A compariso between the experimental results and calculations indicated that the instability associated with irregular austenite perturbations results from the high degree of undercooling. The results suggest that the model can be used successfully to understand the development of the microstructure in duplex stainless steel weld metals.",
    keywords = "microstructure iron and steel metallography, microstructure stainless steel, elemental partioning, weld metal, duplex steel, welds",
    author = "S. Atamert and J.E. King",
    year = "1991",
    month = "3",
    doi = "10.1016/0956-7151(91)90306-L",
    language = "English",
    volume = "39",
    pages = "273--285",
    journal = "Acta Metallurgica et Materialia",
    issn = "0956-7151",
    publisher = "Pergamon Press",
    number = "3",

    }

    Elemental partitioning and microstructural development in duplex stainless steel weld metal. / Atamert, S.; King, J.E.

    In: Acta Metallurgica et Materialia, Vol. 39, No. 3, 03.1991, p. 273-285.

    Research output: Contribution to journalArticle

    TY - JOUR

    T1 - Elemental partitioning and microstructural development in duplex stainless steel weld metal

    AU - Atamert, S.

    AU - King, J.E.

    PY - 1991/3

    Y1 - 1991/3

    N2 - A thermodynamic analysis which is capable of estimating the austenite/ferrite equilibria in duplex stainless steels has been carried out using the sublattice thermodynamic model. The partitioning of alloying elements between the austenite and ferrite phases has been calculated as a function of temperature. The results showed that chromium partitioning was not influenced significantly by the temperature. The molybdenum, on the other hand, was found to partition preferentially into ferrite phase as the temperature decreases. A strong partitioning of nickel into the austenite was observed to decrease gradually with increasing temperature. Among the alloying elements, average nitrogen concentration was found to have the most profound effect on the phase balance and the partitioning of nitrogen into the austenite. The partitioning coefficient of nitrogen (the ratio of the mole fraction of nitrogen in the austenite to that in the ferrite) was found to be as high as 7.0 around 1300 K. Consequently, the volume fraction of austenite was influenced by relatively small additions of nitrogen. The results are compared with the experimentally observed data in a duplex stainless steel weld metal in conjunction with the solid state δ → δ + γ phase transformation. Particular attention was given to the morphological instability of grain boundary austenite allotriomorphs. A compariso between the experimental results and calculations indicated that the instability associated with irregular austenite perturbations results from the high degree of undercooling. The results suggest that the model can be used successfully to understand the development of the microstructure in duplex stainless steel weld metals.

    AB - A thermodynamic analysis which is capable of estimating the austenite/ferrite equilibria in duplex stainless steels has been carried out using the sublattice thermodynamic model. The partitioning of alloying elements between the austenite and ferrite phases has been calculated as a function of temperature. The results showed that chromium partitioning was not influenced significantly by the temperature. The molybdenum, on the other hand, was found to partition preferentially into ferrite phase as the temperature decreases. A strong partitioning of nickel into the austenite was observed to decrease gradually with increasing temperature. Among the alloying elements, average nitrogen concentration was found to have the most profound effect on the phase balance and the partitioning of nitrogen into the austenite. The partitioning coefficient of nitrogen (the ratio of the mole fraction of nitrogen in the austenite to that in the ferrite) was found to be as high as 7.0 around 1300 K. Consequently, the volume fraction of austenite was influenced by relatively small additions of nitrogen. The results are compared with the experimentally observed data in a duplex stainless steel weld metal in conjunction with the solid state δ → δ + γ phase transformation. Particular attention was given to the morphological instability of grain boundary austenite allotriomorphs. A compariso between the experimental results and calculations indicated that the instability associated with irregular austenite perturbations results from the high degree of undercooling. The results suggest that the model can be used successfully to understand the development of the microstructure in duplex stainless steel weld metals.

    KW - microstructure iron and steel metallography

    KW - microstructure stainless steel

    KW - elemental partioning

    KW - weld metal

    KW - duplex steel

    KW - welds

    UR - http://www.scopus.com/inward/record.url?scp=0026128901&partnerID=8YFLogxK

    U2 - 10.1016/0956-7151(91)90306-L

    DO - 10.1016/0956-7151(91)90306-L

    M3 - Article

    VL - 39

    SP - 273

    EP - 285

    JO - Acta Metallurgica et Materialia

    JF - Acta Metallurgica et Materialia

    SN - 0956-7151

    IS - 3

    ER -