Speaker
Description
Additive manufacturing (AM) of cold work tool steel is challenging due to the material’s proneness to thermal cracks and defects. These issues can be reduced by the use of electron powder bed fusion (E-PBF) manufacturing which provides higher build chamber temperature, pre-heating of the build and slower cooling of the builds compared to laser powder bed fusion (L-PBF). Still, microstructure and properties of the as-build parts significantly differ from the conventional manucaftured material, so post treatment is required to achieve high levels of required characteristics. This research reveals the influence of heat treatment and heat treatment + HIP on defects, microstructure and properties of E-PBF high-alloy (Cr-Mo-V) tool steel. Focus is paid on changes in carbide type and morphology, analysis of prior austenite grain size, elimination of defects and morphology of martensite. A correlation between changes in microstructure and mechanical properties of heat-treated and HIPed E-PBF high-alloy (Cr-Mo-V) tool steel is discussed in a comparison to microstructure and properties of conventionally manufactured materials.