Microstructure, Room and High-Temperature Mechanical Properties of As-Built PBF-LB W360 Hot Forming Steel Alloy

To produce increasingly efficient tools with optimized geometry, additive manufacturing is a suitable solution. However, tool steels, due to their high amount of carbon and hardening elements, may be unweldable and therefore difficult to produce using additive manufacturing methods that employ melting. W360 is a hot-forming alloy, and, in this study, it was produced through laser powder bed fusion (PBF-LB). The microstructure and mechanical properties were evaluated on as-built netshape PBF-LB samples. Despite the presence of many alloying elements, this alloy was not sensitive to cracks, and very good results from the defect analysis (defect surface density < 0.2%) were achieved. Microstructure and hardness are homogeneous in the sample except in the last layer due to an upskin effect. As-built netshape samples exhibit very promising mechanical properties up to 400 °C, which could be further improved by heat treatments.