Influence of solidification structure on austenite to martensite transformation in additively manufactured hot-work tool steels.

ABSTRACT: The microstructure of a hot-work tool steel additively manufactured using laser powder-bed fusion (L-PBF), and its response to post heat treatment, is studied in detail by microstructure characterization and computational thermodynamics and kinetics. The high solidification and cooling rates during the L-PBF process lead to suppression of δ-ferrite and instead solidification of an austenite phase directly containing a cellular substructure where the alloying elements have segregated to the inter-cellular regions and where solidification carbides have formed in the cell junctions. The austenite is then partly decomposed into martensite at lower temperatures. The micro-segregation can be predicted by reducing the complex solidification behavior to a diffusion problem in one dimension

SUBMITTER: Chou CY 

PROVIDER: S-EPMC10088486 | biostudies-literature | 2021 Aug

REPOSITORIES: biostudies-literature