Influence and Optimization of Process Parameters on Surface Roughness of Selective Laser Melting of 316L Stainless Steel

To achieve better surface quality in selective laser melting (SLM), this study used 316L stainless steel powder and conducted a systematic design experiment to investigate the influence mechanism of process parameters on the surface roughness of the top and vertical surfaces. Response surface methodology (RSM) was then used for parameter optimization. The results showed that scanning speed has the greatest impact on surface roughness, followed by laser power, while scanning spacing has the least impact. The lowest surface roughness was observed when the volumetric energy density was between 65 J/mm3 and 90 J/mm3. The optimal combination of process parameters was a scanning speed of 637 mm/s, a hatch spacing of 0.08 mm, and a laser power of 191 W. Under these conditions, the surface roughness of the top and vertical surfaces were 4.96 μm and 6.58 μm, respectively, validating the effectiveness of the model.