Welding and Additive Manufacturing Challenges in Nickel Superalloys: The Impact of Hydrogen Embrittlement

Nickel superalloys are indispensable in industries that demand a fusion of high-temperature mechanical strength and exceptional oxidation resistance, making them ideal for aerospace, power generation, and chemical processing applications. Their versatility extends to various welding applications, including coatings, buttering, and additive manufacturing, where they serve as critical components due to their superior performance characteristics. However, a significant challenge faced by these alloys is hydrogen embrittlement—a phenomenon that can severely compromise their mechanical integrity, leading to catastrophic component failures. This review article synthesizes recent research on hydrogen embrittlement in nickel superalloys, with a focus on understanding the underlying mechanisms that contribute to this phenomenon. It explores how welding processes, including the choice of welding parameters and post-weld treatments, influence the susceptibility to hydrogen uptake and subsequent embrittlement. Furthermore, this review highlights effective strategies for prevention, such as the use of low-hydrogen electrodes, controlled welding environments, and post-weld heat treatments designed to minimize hydrogen diffusion. By addressing these critical aspects, this article aims to provide a comprehensive overview of current challenges and advancements in mitigating hydrogen embrittlement, thereby enhancing the reliability and longevity of nickel superalloy components in demanding industrial applications.