Improvement in Corrosion Performance of Additive Manufactured Stainless Steel and Ni-Based Superalloy in NaCl Solution

Abstract

Abstract Additive manufacturing (AM) has numerous advantages over traditional manufacturing methods, such as efficient material usage, production close to the final shape, development of new alloy components, and suitability for low-volume production. Among the AM methods, wire arc additive manufacturing (WAAM), also known as arc direct energy deposition (Arc-DED) is ahead of other AM methods in producing large-scale complex metallic parts at more affordable costs. However, high heat input in the WAAM process, segregation between two successive melting layers, and surface defects due to high surface roughness lead to the mechanical properties and corrosion resistance of these alloys not meeting the desired values. For this purpose, aluminizing process was applied as a secondary process to stainless steel and Ni-based super alloy samples produced by the WAAM method in this study. Then, the corrosion behavior of aluminide coatings in 3.5% NaCl solution was examined by open circuit potential and Tafel extrapolation method. The results of the study showed that the applied aluminide coatings reduced the surface roughness values of the WAAM component while improving the hardness values and microstructure. These aspects were found to decrease the corrosion potential and enhance corrosion resistance in both WAAM components. Aluminide coatings improved the corrosion resistance of stainless steels by 2.32 times and significantly enhanced the corrosion resistance of Inconel alloys by 13.9 times.