Improved wear and corrosion resistance of additively manufactured SS316L by laser remelting process
Rajendra Hodgir, Ramesh Singh, Soham Mujumdar
Abstract
Directed energy deposition is an efficient and flexible additive manufacturing technique that has broad application prospects due to its ability to fabricate intricate structures with heterogeneous properties. In this study, the laser-based directed energy deposition (L-DED) technique is employed to deposit an austenitic stainless steel 316L powder at a significantly high deposition rate. In recent developments, laser remelting (LR) has been explored as a superior alternative for enhancing the surface integrity of the components produced by L-DED. This study endeavours to examine the impacts of LR, emphasizing the improvement of wear and corrosion resistance. The grain refinement is achieved through laser remelting, which eventually leads to a 34 % improvement in micro–hardness over the as-deposited sample; as a result of increased micro–hardness, wear resistance improved by 66 % when compared to the as-deposited specimen. Furthermore, the corrosion resistance performance of the laser-remelted samples is compared with as-deposited samples by electrochemical impedance spectroscopy (EIS) in a solution of 3.5 % NaCl solution. The remelted sample showed improved corrosion resistance, which is attributed to the grain refinement due to rapid solidification in LR. This study demonstrates that laser remelting can be an effective way to improve the wear and corrosion resistance of SS316L, which enlarges its application in harsh environments.