Effect of Scanning Speed on Microstructure, Hardness, and Corrosion Behavior of Additively Manufactured 316L SS in a Chloride-Rich Environment

Abstract

316L stainless steel is widely used in chemical processing, shipbuilding, medical implants, and nuclear components due to its excellent corrosion resistance and mechanical performance. In this study, selective laser melting (SLM) was employed to fabricate 316L stainless steel under various laser scanning speeds (600-1000 mm/s) to investigate the combined effects on microstructure, porosity, hardness, and corrosion behavior. Results show that higher scanning speeds promote microstructural refinement and increase hardness, reaching 372.4 HV for the AB1 condition, but also lead to increased porosity. Electrochemical tests in 3.5 wt.% NaCl solution revealed that corrosion resistance improves at lower scanning speeds, with the AB5 sample achieving a corrosion current density of 2.722 x 10(-8) A cm(-2) and a polarization resistance of 93.97 x 10(4) Omega cm(2), outperforming even wrought 316L stainless steel. This study demonstrates that controlling scanning speed enables a balance between strength and corrosion resistance, providing valuable insights for additively manufactured 316L components in demanding industrial environments.