NbC particles-reinforced 316L stainless steel fabricated by selective laser melting: microstructure, mechanical properties, and strengthening mechanisms

316L stainless steel is widely used in engineering fields; however, its low hardness, yield strength, and wear resistance limit its applications. In this study, enhanced 316L stainless steel with 2 wt% NbC was manufactured using Selective Laser Melting (SLM). Its relative density exceeds 99% at its highest, with a microhardness exceeding 300 HV_0.05. Additionally, it was observed that some NbC dissolved into the matrix while others precipitated and dispersed within the matrix. The matrix grain size was refined to approximately 5 μm, and at the bottom of the samples, the < 100 > crystallographic orientation shifted to < 510 > , presenting a cubic texture. Some samples exhibited adhesive wear mechanisms in sliding wear tests, with the lowest wear rate at 1.69 × 10^–4 mm³/N·m. The tensile properties of the material were related to the scanning strategy; under the scanning strategy with a layer-to-layer rotation angle of 90° and island area of 60 × 10 mm², the highest yield strength can reach 640 MPa. The two forms of NbC mainly enhance the matrix through the reinforcement of Hall–Petch (H–P) and Geometrically Necessary Dislocation (GND) strengthening effects.