Achieving balanced uniform and local corrosion performance of SS 316L/IN625 hybrid alloy manufactured by directed energy deposition

Abstract

This study investigates hybrid stainless steel (SS) 316L/Inconel 625 (IN625) materials via DED for hydrofluoric acid (HF) corrosion resistance. 20% SS 316L + 80% IN625 (20% 316L) exhibits low uniform corrosion (0.35 mm/y) and improved local corrosion performance. High CrO content in its passive film ensures uniform corrosion resistance. The thermodynamic analysis combined with microstructure observation shows reduced Nb content in 20% 316L's Laves phase, enhancing resistance to micro-galvanic local corrosion. This study provides insights into the design and manufacturing technology of corrosion-resistant materials in harsh corrosive environments.