In current work, the heat treatment behavior of AISI H13 tool steel produced through Direct Laser Metal Deposition (DLMD) is studied using dilatometry. Owing to the intrinsic characteristics of the process, the as-built microstructure mainly consists of partially tempered martensite. Furthermore, intercellular micro-segregation leads to the stabilization of retained austenite (RA) in the as-built microstructure to considerable amounts of up to 12 vol.%. Quenching of the samples resulted in a partial recovery of the cellular/dendritic solidification structure and reduced the amount of RA to less than 2 vol.%. The material responses to heat treatment in the as-built and quenched conditions were compared, also in the light of past results obtained for samples produced by Laser Powder Bed Fusion (LPBF). While the two methods showed similar behavior in the quenched state, in the as-built state their behavior was different due to diverse thermal history related to each processing method.
展开▼
