TY  - JOUR
AU  - Ofner, Nicole
AU  - Meindlhumer, Michael
AU  - Kunnas, Peter
AU  - Asci, Atacan
AU  - Gocnik, Marek
AU  - Stark, Andreas
AU  - Höbenreich, Philipp
AU  - Aumayr, Christin
AU  - Wu, Liang
AU  - Turk, Christoph
AU  - Keckes, Jozef
AU  - Bodner, Sabine Carmen
TI  - In situ characterization of phase and microstructural evolution during multi-step heat treatment of an additively manufactured tool steel
JO  - Journal of materials research and technology
VL  - 37
SN  - 2238-7854
CY  - Rio de Janeiro
PB  - Elsevier
M1  - PUBDB-2026-00583
SP  - 2528 - 2538
PY  - 2025
AB  - mechanicalproperties, usually involving complex, multi-step heat treatment procedures. This study investigates themicrostructural evolution and its impact on mechanical properties of an AM tool steel through successive heattreatment steps, including the as-built, spheroidized, quenched, sub-zero treated, and three repeated temperedconditions. For the first time, the dynamic mechanisms of phase transformation and carbide evolution duringheat treatment of an AM tool steel are systematically revealed through the combined application of in situsynchrotron X-ray diffraction and multi-scale characterization techniques. (Cr,Mo,Mn,V)23C6 carbide precipitationwas revealed alongside (retained) austenite, martensite and δ-ferrite, with the phase contents varying acrossthe individual heat treatment steps. A strong correlation between (retained) austenite, (tempered) martensite andVickers hardness was observed, with a final Vickers hardness of 577 ± 5 HV10 in the fully heat-treated condition.Furthermore, the as-built microstructure strongly influenced the subsequent thermal processing behavior asindicated by the stability of δ-ferrite throughout heat treatment, originating from austenite by-passing during LBPBF,and the early formation of M23C6 carbides during spheroidizing, driven by Cr segregation resulting from theLB-PBF process. Therefore, this study highlights the influence of AM microstructures on heat treatment responsesand offers new insights into carbide formation and phase transformations of AM tool steels. The findingsemphasize the critical role of post-printing heat treatments in tailoring the microstructural and mechanicalproperties of tool steels, thus advancing the understanding of specific heat treatment strategies for AMcomponents.
LB  - PUB:(DE-HGF)16
DO  - DOI:10.1016/j.jmrt.2025.06.115
UR  - https://bib-pubdb1.desy.de/record/645078
ER  -