Tensile performance of 316L stainless steel by additive manufacturing

Selective laser melting (SLM) technology, as one of the preferred methods for additive manufacturing of alloy products, has developed rapidly in the past two decades.However, further development and application of the SLM technology has been hindered due to the lack of thorough descriptions of mechanical properties of products.In this study, the basic mechanical properties of 48 selective laser-melted 316L stainless steel samples with two different thicknesses and five orientations, which were manufactured by two kinds of equipment, are investigated based on tensile tests.For the samples, the Young's modulus ranged from 172.61 to 215.55 GPa, the yield tensile strength ranged from 446.90 to 583.47 MPa, the ultimate tensile strength ranged from 576.22 to 734.43 MPa, and the failure elongation ranged from 20.69% to 49.56%.Both the yield tensile strength and ultimate tensile strength are much higher than the specified values of 316L stainless steel plate and stainless steel strip after the solid-solution treatment, and both are higher than those of forging without annealing treatment.Meanwhile, the yield ratio is much higher than those of steel plate and steel strip treated by solid solution.The mechanical properties of samples with different thicknesses and orientations manufactured by different equipment appear to be significantly different.Based on further SEM tests and existing results of previous researches, the causes leading to the obvious differences in mechanical properties and their variation trends with the orientation were analyzed. © 2020, Editorial Office of China Civil Engineering Journal. All right reserved.