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Enhanced localized corrosion resistance of Ni-based alloy 625 processed by directed energy deposition additive manufacturing

Published

Author(s)

Karthikeyan Hariharan, Andrew Iams, James Zuback, Todd Palmer, Narasi Sridhar, Rashed Alazemi, Gerald Frankel, Eric Schindelholz

Abstract

We report a significant improvement in localized corrosion resistance of Ni-based alloy 625 processed by directed energy deposition (DED) in an aggressive aqueous chloride environment. Disparities observed in the polarization behavior between DED and commercial, wrought alloy 625 are analyzed in terms of differences in composition and microstructural features. We attribute the exceptional localized corrosion resistance of the DED alloy to the refined distribution of secondary phases imparted by the additive manufacturing process. The larger (> 1 μm) and prototypical precipitates present in the wrought material, primarily Ti,Nb rich nitrides, served as pit initiation sites and likely degraded its corrosion resistance.
Citation
Corrosion Science

Keywords

superalloys, crevice corrosion, inclusion, pitting corrosion, segregation, passivity

Citation

Hariharan, K. , Iams, A. , Zuback, J. , Palmer, T. , Sridhar, N. , Alazemi, R. , Frankel, G. and Schindelholz, E. (2024), Enhanced localized corrosion resistance of Ni-based alloy 625 processed by directed energy deposition additive manufacturing, Corrosion Science, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=957208 (Accessed April 19, 2025)

Issues

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Created April 15, 2024, Updated April 14, 2025