Hot corrosion behaviour of wire-arc additive manufactured Ni-based superalloy ATI 718Plus®. (September 2019)

• Record Type: Journal Article
• Authors: Asala, G.; Andersson, J.; Ojo, O.A.
• Is Part Of: Corrosion science. Volume 158(2019)
• Publication Date: 2019-09
• Subjects: Hot corrosion -- Metal additive Manufacturing -- WAAM -- Ni-based superalloy -- ATI 718Plus -- TEM -- Electron microscopy -- High-temperature corrosion; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2019.07.010
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: Significant elemental micro-segregation is observed in ATI 718Plus produced by wire-arc additive manufacturing technique (WAAM). WAAM ATI 718Plus, in the as-processed condition, shows a significantly lower resistance to hot corrosion in comparison with the wrought counterpart. The lower resistance is attributed to the depletion of Nb and Mo in the dendrite core regions . Application of innovative post-deposition heat treatment was used to improve the hot corrosion characteristics. Abstract: The hot corrosion behaviour of wire-arc additive manufactured and wrought ATI 718Plus ® are studied. ATI 718Plus ® produced by the additive manufacturing process, in the as-processed condition, exhibits a significantly lower hot corrosion resistance in comparison to the wrought alloy. Analytical electron microscopy and spectroscopy techniques, with corroboration by thermodynamic calculations, are used to identify the underlying cause of the poor hot corrosion resistance. Based on the understanding accrued from the analyses, post-processing heat treatments are used to improve the hot corrosion resistance, which is valuably pertinent to the application of ATI 718Plus ® produced by additive manufacturing in hot corrosive environments.