Corrosion response of steels fabricated through arc directed energy deposition additive manufacturing: a review.

Steels exhibit distinct properties that underscore their pivotal role in critical industries, such as maritime, aerospace, automotive, petrochemical, and biomedicine. In recent times, there has been an increasing trend towards manufacturing near--shape steel components through various additive manufacturing (AM) modalities, utilizing intricate 3D model data. Initially, powder bed fusion (PBF) technology garnered significant attention for the fabrication of steel components. Nonetheless, arc-directed energy deposition (arc-DED), also known as wire arc additive manufacturing (WAAM) technology, is progressively gaining prominence in the AM enterprise due to its high production rate, the ability to print large-scale components, and notably, reduced capital investment. While early research on WAAM-fabricated steels primarily focused on microstructural and mechanical characteristics, there is an increasing emphasis on the corrosion performance of WAAM steel components. These components often encounter exposure to corrosive environments in their intended applications. The existing literature lacks a comprehensive review that delves into the nuanced factors influencing the corrosion behavior of WAAM-fabricated steels and the primary corrosion mechanisms governing their degradation. Therefore, this review is dedicated to exploring the corrosion properties of WAAM-fabricated steels, identifying key parameters influencing their degradation behavior. Moreover, it offers an in-depth examination and discussion of the underlying mechanisms governing corrosion-induced deterioration. Furthermore, this review meticulously scrutinizes the microstructural features and WAAM technologies, providing clarity and organization regarding details relevant to the corrosion of WAAM steel components. To conclude, the paper highlights the existing research gaps related to the corrosion of WAAM steel, delineating potential avenues for future research.