EFFECT OF PRE-HEATING DURING SELECTIVE LASER MELTING OF CHROMIUM STEEL ON STRUCTURE AND PROPERTIES

 The paper presents the results of investigation of the influence of platform pre-heating temperature during selective laser melting (SLM) and subsequent heat treatment on the microstructure, phase composition and mechanical properties of chromium steel. The dependence of the porosity of the compact material on energy density of SLM was revealed. The microstructure of the samples is characterized by narrow grains elongated along the building orientation. During printing with platform pre-heating, the average length of grains increases from 156 to 563 μm, while the average width stays the same, about 30 µm. After heat treatment, carbides of the MC and M23C6 types are located at the grain boundaries. X-ray diffraction patterns of the samples contain peaks corresponding to the body-centered cubic lattice. Platform pre-heating during SLM process allowed to increase the ductility of the material by 6% (from 12 to 18%), while maintaining the strength properties. The results showed that the application of platform pre-heating and subsequent heat treatment enables to control the microstructure and mechanical properties. The materials of the article were presented at the International Scientific and Practical Conference “Advanced Engineering Technologies (AET 2024)” held in St. Petersburg on May 13–17, 2024.