ИСТИНА

In the presented study the anisotropy of mechanical properties and sensitivity to loading conditions are characterized for stainless steel 316L, fabricated via laser powder bed fus ion (LPBF). Experimental set for mechanical testing includes LPBF samples for tension, compression and shear, which were built in three different mutually orthogonal directions. Test results show a dependency of mechanical characteristics to the build direction in some cases, while no significant differences in other ones. In particular, tensile sample built vertically has lower yield and ultimate stress in comparison with horizontally oriented. Moreover, numerical simulation of build process revealed high residual stresses in specimens, and the stress level depends on orientation. Virtual tensile test was also performed with the presence of predicted residual stresses. Simulation show, that Young’s modulus, measured in the sample with presence of residual s tresses, is reduced to about 25% in comparison with conventional value of 190 200GPa at room temperature. Physical tensile test of considered steel samples also shows similar difference in Young’s modulus. Therefore, the residual stress is a potential expl anation of the apparent anisotropy, and it should be considered together with other factors of anisotropy, such as porosity and microstructure. The proposed experimental setup gives data to develop anisotropic elastoplastic model and failure criteria, whic h are also discussed in the presented study. This research was supported by the Russian Science Foundation (Grant No. 20 11 20230).