Studies on Mechanical and Electro-Chemical Properties of Laser Direct Energy-Deposited AISI 316L Stainless Steel

In this study, austenitic stainless steel (AISI 316L grade) coupon samples were developed by laser direct energy deposition (LDED) technique (using a 6 kW fiber-coupled diode laser with a wavelength of 1000 and 3.6 mm beam diameter) with 600–1000 W power input and 2–5 mm/s scan speed at a powder feed rate of 50 g/min. The clad zone was thoroughly investigated in terms of microstructure, phase, micro and nanohardness, and mechanical and electrochemical properties and correlated with input LDED parameters to determine the optimum process window. The samples processed under optimal process parameters were subjected to tensile testing, followed by a detailed study of the fractured surface to determine the mechanism of tensile deformation and failure. LDED leads to microstructural refinement and, hence, increases its microhardness in comparison with base plate. The wear (against the WC ball in fretting mode) and corrosion resistance (in a 3.56 wt pct NaCl solution) were improved for LDED coupons in comparison with that of the wrought alloy. Tensile behavior shows a marginal increase in yield strength and ultimate tensile strength in addition to ductility as compared to wrought alloy. Graphical Abstract