Post-processing of Wire Arc Additive Manufactured Stainless Steel 308L to Enhance Compression and Corrosion Behavior using Laser Shock Peening Process

Laser shock peening (LSP) is a novel non-contact surface modification technique to enhance the corrosion and compression behavior of stainless steel 308L (SS308L) material for a cryogenic application. SS308L is commonly used as a weld filler, weld electrode and cryogenic environment due to its low carbon content and good mechanical and high corrosion resistance properties. In this present study, wire-arc additive manufacturing (WAAM) has been utilized to manufactured SS308L material and studied the compression, corrosion, wettability and surface properties of the material. Further, the nanosecond laser shock peening has been utilized to modify the additive-manufactured SS308L surface and mechanical properties. From the experimental results, it has been observed that the uni-directional flow path (UDFP) deposition has better corrosion resistance wettability and surface finish than the bi-directional flow path (BDFP) deposition on wire-arc additive-manufactured SS308L material due to its more uniform microstructure and smoother surface finish. In addition, the post-processing treatment (LSP) of SS308L materials has improved the compressive strength of additive-manufactured SS308L material with 20.6 and 15.9% as compared to UDFP and BDFP due to grain surface refinement and increases in dislocation density. The corrosion rate of LSP-treated materials was reduced by 20.7% compared to the UDFP materials due to the higher corrosion potential and lower corrosion current density. The higher surface roughness has produced better passive film formation to enhanced corrosion resistance in the UDFP with LSP. Finally, the microstructure and chemical composition have been analyzed using scanning electron microscope and energy-dispersive x-ray spectroscopy.