Effect of Alloying on the 316L and 321 Steels Samples Obtained by Selective Laser Melting

The main objective is to study the structure and mechanical properties of the samples based on 316L and 321 stainless steel powders with different particle size distribution, produced by selective laser melting. Despite the fact that the SLM technique involves almost complete melting of the metal powder particles, the difference in particle size and a fused layer thickness leads to differences in mechanical properties due to incomplete melting of large particles. Therefore, for each type of steel it's necessary to experimentally select fusion mode. Samples for impact strength, tensile strength and density tests were grown. The studies revealed that samples from a larger steel powder 316L, obtained at a larger thickness of 40 microns, with increasing energy input don't reach the characteristics that have been obtained at a thickness of 20 micron layer. Samples of fine steel powder 321, constructed with a layer thickness of 40 microns, have the same mechanical properties as the samples constructed with a layer thickness of 20 microns, with an increase in the energy input of 1.5. On the basis of the data obtained it's shown that the distribution of powder particle size has a significant impact on the quality of the samples.