Corrosion Rate Performance of SS316L Base Material with GTAW Welding Utilizing ER316LSi Filler on Microstructure

SS316L material exhibits superior corrosion resistance. The two grade compositions, comprising nickel and molybdenum, enable the alloy to resist acids and chlorides without degradation. Due to its exceptional corrosion resistance, both metals are among the few classified as "marine grade stainless steels." Gas Tungsten Arc Welding (GTAW) is executed to guarantee sufficient corrosion resistance during installation. This study analyzes the outcomes of welding ER316LSi as a filler material with SS316L base metal, focusing on microstructure, EDAX analysis, and corrosion rate. This study did not perform hardness testing. This study will indicate welding variables for future research on specific applications, utilizing various weld blades and current parameters. Corrosion testing, encompassing Tafel and Electrochemical Impedance Spectroscopy, indicates that the SS316LSi weld metal will yield a higher degree of ferrite development in the weld region. The welding temperature significantly influences the ferrite structures. The corrosion rates for each electrolyte solution are as follows: for the seawater electrolyte solution, a current of 110A yields a rate of 8.39857 x 10 -6 mpy, 120A results in 7.09315 x 10 -6 mpy, and 130A produces a rate of 7.85427 x 10 -6 mpy. The MgCl 2 electrolyte solution exhibits a concentration of 110A = 7.2195 × 10 -6 mpy, a current of 120A = 7.2156 × 10 -6 mpy, and a current of 130A = 7.1406 × 10 -6 mpy. The corrosion resistance at a current of 120 amperes is greater in seawater conditions than at a current of 130 amperes in MgCl2 solutions. The corrosion rate and reductions in Fe, Mo, Cr, and Mn following 14 days of immersion testing in sewage and MgCl2 are the reasons that low-heat-input or solid-phase bonding techniques can significantly enhance pitting resistance compromised by welding.