Processability and Microstructural Evolution of W360 Hot Work Tool Steel by Directed Energy Deposition

Abstract Laser directed energy deposition (L-DED) was used to produce samples of the newly patented W360 hot work tool steel by Böhler. The process parameters were optimized obtain nearly fully dense through production and analysis single deposited tracks layers. Subsequently, bulk underwent a hardening heat treatment, consisting austenitizing, air quenching, tempering. analysed in as-built condition (AB), after quenching (Q) following tempering cycles (HT) observe microstructural evolution. microstructure investigated using optical scanning electron microscopes, dispersive X-ray analysis, diffraction analysis. Furthermore, evolution with differential calorimetry, while mechanical response evaluated microhardness test. It found that AB exhibited dendritic-cellular tempered martensite laths. thermal history completely modified austenitizing treatment followed resulting martensitic Q sample did not display typical L-DED process. completion revealed presence Mo-rich carbides dispersed matrix. HT mean 634 HV, remaining constant along entire building direction from substrate last layer, indicating homogeneous microstructure. This high value, similar other steels such as H13, makes very promising candidate for build repair purposes. Graphical