An investigation on corrosion behaviour of additively manufactured IN 718 in nitric acid; [Une étude sur le comportement à la corrosion dans l’acide nitrique de l’IN 718 fabriqué de manière additive]

Abstract

Nickel-based superalloys are extensively used in different high-temperature applications due to their excellent strength and performance at high temperatures, such as gas turbines. However, the properties of these alloys vary significantly with changing the manufacturing methods. Additive manufacturing is a new and advanced manufacturing technique that can produce metallic components with great precision, accuracy, and close tolerance. This work focuses on investigating the performance of additively manufactured Inconel (IN) 718 by laser bed powder fusion technique (LPBF) in 1 M HNO3. Open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), and Tafel polarization curves (TPC) have been used to assess the corrosion behaviour of IN 718 in 1 M HNO3. Scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) are employed to know the qualitative effects of corrosion on the surface of IN 718. X-ray photoelectron spectroscopy (XPS) has been used for depth profiling of IN 718 elements to understand the localised corrosion behaviour of IN 718. The results show that additively manufactured IN 718 can be successfully used in strong corrosive and acidic environments. © 2025 Canadian Institute of Mining, Metallurgy and Petroleum.