Laser powder bed fusion and directed energy deposition of a novel hot work tool steel: a comparative study

To address the challenges in processing medium-carbon hot work tool steels by laser-based additive manufacturing (AM), a recently developed hot work tool steel with improved processability was processed by both laser powder bed fusion (L-PBF) and laser-directed energy deposition (L-DED). Microstructure and phases in as-built (AB) and quenched (Q) states were compared for both processing routes. Hardness, Charpy V notch impact toughness, tempering- and thermomechanical softening-resistance, after direct double tempering from AB condition (DT) and quenching and tempering (QT) were measured and assessed. Properties were then compared with those of AM-, as well as wrought-AISI H13 hot work tool steel. The results suggest that the new steel exhibits comparable mechanical and thermomechanical properties to steel H13. Finally, practical case studies of repairing tools made from H13, using the new tool steel (L-DED), and producing relatively large molds with complex geometries (L-PBF) were dem...