Production of corrosion-resistant 316L stainless steel clads on carbon steel using powder bed fusion-selective laser melting

Abstract

Powder bed fusion-selective laser melting (PBF-SLM) was used to produce corrosion-resistant 316L stainless steel clads on 1018 carbon steel substrates. The PBF-SLM parameters such as laser power, laser-scanning speed, hatch spacing, and layer thickness were optimized to attain maximum clad density and a superior metallurgical bond to the substrate. Typical energy densities that are required for producing dense 3D parts (˜100 J/mm3) was inadequate for cladding operations, and a higher energy density (333–1333 J/mm3) was necessary to produce low-defect clads with good adherence to the substrate. A maximum clad thickness of 133.14 μm was achieved at the lowest tested scan speed of 100 mm/s after ten layers of powder melting. The clads had lower chromium content than the 316L powder due to evaporative losses experienced during laser melting process. However, chromium contents in the range of 13–15% were successfully achieved in all cladded specimens. Increasing laser scan speeds had a negative impact on the nanoindentation hardness of the clads; however, the clad hardness at all scan speeds was found to be higher than AISI 316L SS. Electrochemical tests showed that the corrosion properties of clads produced at low laser scan speeds were comparable to AISI 316L SS.