Sammendrag
The evolution of new techniques for processing materials is being of interest for the current industry. Some scientific researchers have focused their studies on knowing more about them, and the results show a promising future for AM techniques which present advantages over the traditionally used methods. The purpose of this study is to investigate the effect of process parameters on the microstructural and corrosion properties of AISI 316L SS. Porosity, surface roughness, hardness, and grain size were studied for specimens printed with energy densities ranged from of 51.17 to 173.91 J/mm3 as a result of different combinations of processing parameters. By using a Taguchi L9 orthogonal array the experiments on porosity were conducted. The influence on corrosion resistance was obtained by performing cyclic potentiodynamic polarization tests (CPP) in 3.5%wt NaCl solution for different energy densities and positions (Z axis). The main corrosion values of the AM samples were studied for the two planes (XOY, XOZ) and the results were compared to those obtained from the common manufactured samples. The fitted model determined 99.38 J/mm3 as the optimal energy density to produce samples with almost no porosity. The following study of variance ANOVA confirmed the scanning speed as the most influential factor in reducing the porosity percentage with a 74.86% of contribution followed by the position 22.82% and finally the laser energy 2.26%. The corrosion resistance of the samples was reduced with the increase in the percentage of porosity. The existence of anisotropy in the corrosion resistance for the AM was not confirmed, neither the presence of inclusions, such as MnS from the EDS analysis which explained the greater corrosion resistance found for the SLM samples as compared to the common manufactured ones.