Influence of Laser Powder‐Based Directed Energy Deposition and Heat Treatment on the Thermal Conductivity of Cold‐Work Tool Steel X65MoCrWV3‐2

Press hardening tools require high hardness, wear resistance, and especially sufficient thermal conductivity to ensure rapid cooling and minimize thermal fatigue. The cold‐work tool steel X65MoCrWV3‐2 is widely used for such applications, yet its thermal performance in additively manufactured form remains largely unexplored. This study investigates the room temperature thermal conductivity of specimens produced by laser‐based directed energy deposition using powder feedstock and tempered at two different temperatures. Both chemical and microstructural contributions to thermal transport are assessed using laser flash analysis, modulated differential scanning calorimetry, microscopy, and supporting CALPHAD calculations. Results show anisotropic thermal conductivity in all states, with anisotropy increasing upon tempering. Compared to conventionally manufactured X65MoCrWV3‐2, the additively manufactured and tempered material exhibits a 15%–20% lower thermal conductivity. CALPHAD results indicate that this reduction is driven primarily by microstructural effects rather than compositional differences between specimens. These findings provide essential data for the design of additively and hybrid‐manufactured press hardening tools and form a basis for predictive modeling of thermal conductivity under varied heat treatment conditions.