<p>In this study, IN625 was developed using the Wire Arc Additive Manufacturing technique (WAAM) employing optimized parameters. This study establishes the originality of the work by evaluating the double-aged WAAM-processed IN625 alloy in a highly corrosive LiCl–KCl–EuCl₂ molten salt system at 550 °C—a corrosive environment not previously reported for additively made IN625. The fabricated specimens were subjected to a controlled heat treatment regime consisting of solutionizing at 1250°C followed by aging at 750°C and subsequent double-aging at 650°C aimed at stress removal and microstructure refinement. A comprehensive hot salt corrosion test was conducted using LiCl-KCl-EuCl₂ at 550°C for 24, 48 and 96 hours to assess the effect of heat treatment on the corrosion resistance of the alloys. The precipitation hardening and grain boundary strengthening by the double-aging heat treatment resulted in a high microhardness of 302.7HV. Hot corrosion performance was evaluated and it was inferred that the double-aged specimen exhibited superior corrosion resistance with minimum weight loss. The surface morphology of the corroded specimens was characterized using microstructural analysis and the corrosion mechanism was deduced using elemental analysis. Results inferred that the double-aged specimens showed superior corrosion resistance in a molten salt environment at 550°C.</p>