Analysis of heat treatment effects on the microstructure and mechanical properties of 3D-printed and conventionally manufactured H11 steel – POSTER

Fialová Pavlína - University of West Bohemia (Czech Republic)

H11 medium-carbon hot work tool steel was printed using Laser Powder Bed Fusion (LPBF) and subjected to various heat treatment regimes to relieve internal stress and enhance mechanical properties. For comparison, the same heat treatments were applied to conventionally produced H11 steel (cold-rolled and annealed). Microstructural analysis, tensile testing, and HV 10 hardness measurements were performed on both materials. The conventionally produced steel initially exhibited low strength (600 MPa) but high ductility (41%), whereas the as-printed 3D steel had a much higher tensile strength (over 1500 MPa) but significantly lower ductility (5%). After heat treatment, conventional steel consistently achieved superior strength and ductility compared to its additively manufactured counterpart. By applying hardening followed by two-step tempering at 550°C, the 3D-printed steel reached a tensile strength of 2030 MPa with 4% elongation, while conventionally produced steel attained 2100 MPa strength and 14% ductility under the same conditions. The structure of both steels became almost identical when the temperature and heat treatment time increased.