The Mechanical Behavior of AISI H13 Hot-Work Tool Steel Processed by Selective Laser Melting under Tensile Stress

AISI H13 tool steel is commonly used in hot-working applications include die casting dies, inserts, forging dies, extrusion dies, etc. Molds fabricated by selective laser melting (SLM) with conforming cooling channels can maintain a steady and uniform cooling performance to the molding parts, which ensures high quality of the products and general reduction of the cycle time. Therefore, SLM process has gained increasing attention in the hot-work tool field. The present study concerns the properties of H13 materials that with and without preheating during the SLM process. X-ray diffraction (XRD), field emission scanning electron microscope (SEM), and high-temperature tensile tests were applied to investigate the phases, microstructures and resultant mechanical properties of SLM processed H13. Results show that the application of preheating during SLM process results in a more homogeneous microstructure of the material with better mechanical properties compared to those without preheating. High-temperature tensile strength increased from 1066 MPa to 1183 MPa, the total elongation increased from 5.7% to 8.1%. The high-temperature tensile strength of those parts with preheating was higher than those of the treated commercial H13 tool steel, while the total elongation was much lower than those commercial materials.