Effect of Scanning Speed on Micromorphology and Properties of 316L Stainless Steel Formed by Selective Laser Melting

316L stainless steel specimens were prepared by selective laser melting (SLM) at different scanning speeds (700-1 200 mm·s^-1). The influence of the scanning speed on the micromorphology and mechanical properties was studied. The results show that with the increase of the scanning speed, the surface roughness and the internal voids of the specimen increased in number; the tensile strength, percentage elongation after fracture, and hardness of the specimen first slowly increased, and then rapidly decreased when the scanning speed was greater than 1 000 mm·s^-1, while the yield strength showed a decreasing trend. With increasing scanning speed, the impact absorption energy of the specimen first remained stable and then decreased, the number of holes and cracks near the impact fracture gradually increased, and the impact fracture form changed from ductile-brittle fracture to brittle fracture. When the scanning speed was 700-800 mm·s^-1, the impact toughness of the specimen was the best, whose impact absorption energy was 58.6-60.0 J.