TY - CONF

T1 - Grain refinement of high-Mn wear-resistant cast steel by means of heterogeneous nucleation

AU - Presoly, Peter

AU - Wallner, Michael

AU - Thiele, Kathrin

AU - Bernhard, Christian

AU - Mayer, Michael

AU - Ressel, Gerald

AU - Tize, Thomas

PY - 2024/9/25

Y1 - 2024/9/25

N2 - Understanding and controlling the primary solidification, particularlythe formation of first grains, is of significant relevance. Generally, high-Mn steels,such as alloy Mn13, exhibit a coarse-grained microstructure in the millimeterrange and are known for their high strain hardening ability and thus, excellentcyclic deformation resistance. To further improve the cyclic mechanicalproperties, this study aims to increase the strength of the alloy via grainrefinement. From a comprehensive literature research, the nonmetallicinclusions AlCeO3, CeO2, Ce2O3 and Ce2O2S were identified as the most promisingparticles for the heterogeneous nucleation of austenite. Based on this literaturereview, various grain refining agents were evaluated and finally the grain refiningagent from ELKEM (WearSeedTM) was selected for test melts. This resulted in asuccessful grain refinement and the grain size was reduced by over 80% (from1550μm to 285μm). However, the process window for a successful grainrefinement is only very small. For a deeper understanding, thermodynamiccalculations with FactSage on the interaction of O-S-Ce-Al in high-Mn steel meltsand particle analyses of the potential nuclei by automated SEM-EDS were carriedout. The framework conditions for a successful grain refinement weresystematically developed depending on the casting temperature, dissolved O andS, and the addition of Al and Ce. Finally, the static and cyclic mechanicalproperties of the grain refined high-Mn steel cast were determined using tensileand low cycle fatigue testing and showed very promising results.

AB - Understanding and controlling the primary solidification, particularlythe formation of first grains, is of significant relevance. Generally, high-Mn steels,such as alloy Mn13, exhibit a coarse-grained microstructure in the millimeterrange and are known for their high strain hardening ability and thus, excellentcyclic deformation resistance. To further improve the cyclic mechanicalproperties, this study aims to increase the strength of the alloy via grainrefinement. From a comprehensive literature research, the nonmetallicinclusions AlCeO3, CeO2, Ce2O3 and Ce2O2S were identified as the most promisingparticles for the heterogeneous nucleation of austenite. Based on this literaturereview, various grain refining agents were evaluated and finally the grain refiningagent from ELKEM (WearSeedTM) was selected for test melts. This resulted in asuccessful grain refinement and the grain size was reduced by over 80% (from1550μm to 285μm). However, the process window for a successful grainrefinement is only very small. For a deeper understanding, thermodynamiccalculations with FactSage on the interaction of O-S-Ce-Al in high-Mn steel meltsand particle analyses of the potential nuclei by automated SEM-EDS were carriedout. The framework conditions for a successful grain refinement weresystematically developed depending on the casting temperature, dissolved O andS, and the addition of Al and Ce. Finally, the static and cyclic mechanicalproperties of the grain refined high-Mn steel cast were determined using tensileand low cycle fatigue testing and showed very promising results.

M3 - Paper

SP - 238

T2 - Liquid Metal Processing & Casting Conference 2024

Y2 - 22 September 2024 through 25 September 2024

ER -