Hot corrosion behavior of additively manufactured stainless steel 316L and Inconel 718 in MgCl2/KCl/NaCl chloride salts at 700 °C. (October 2022)

• Record Type: Journal Article
• Authors: Shi, Hao; Wu, Tao; Gong, Qing; Ding, Wenjin; Chai, Yan; Weisenburger, Alfons; Chang, Litao; Zhang, Zhao; Wang, Kangli; Richter, Julia; Niendorf, Thomas; Müller, Georg
• Is Part Of: Corrosion science. Volume 207(2022)
• Publication Date: 2022-10
• Subjects: Additive manufacturing, 3D-printing -- Corrosion -- Microstructure -- Molten salts, Austenitic stainless steel 316L, Inconel 718; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2022.110561
• Languages: English
• ISSNs: 0010-938X

Abstract

Abstract: Two additively manufactured (AM) materials, i.e., stainless steel 316 L (SS316L) and Ni-base superalloy Inconel 718 (IN718), have been exposed to MgCl2 -KCl-NaCl (47.1–22.7–30.2 mol%) salts at 700 °C to investigate their corrosion behavior. Corrosion tests were conducted using SS316L processed by laser metal deposition (LMD), IN718 by laser powder bed fusion (PBF-LB) as well as conventionally processed counterparts. The obtained results reveal that LMD SS316L is characterized by inferior corrosion resistance, mainly due to the segregation of δ-ferrite at grain boundary (GB). Two different types of corrosion morphologies, uniform corrosion and GB-driven corrosion, are observed in both AM and the conventionally processed IN718 samples. The GB-driven corrosion is accelerated by the evolution of δ-phase in case of IN718. Highlights: The LMD SS316L is less corrosion resistant than commercial SS316L in MgCl2 -KCl-NaCl. The corrosion attack of LMD SS316L is promoted by the δ-ferrite at grain boundary. PBF-LB IN718 shows the corrosion behavior similar to the commercial IN718. Two types of corrosion are observed in PBF-LB and commercial IN718.