High-temperature oxidation and hot corrosion of Ni-based single crystal superalloy in the incubation stage. (15th April 2023)

• Record Type: Journal Article
• Authors: Gong, Na; Meng, Tzee Luai; Teo, Siew Lang; Cao, Jing; Lee, Coryl J.J.; Tan, Chee Kiang Ivan; Tan, Dennis C.C.; Suwardi, Ady; Lin, Ming; Misra, R.D.K.; Liu, Hongfei
• Is Part Of: Corrosion science. Volume 214(2023)
• Publication Date: 2023-04-15
• Subjects: Hot corrosion -- High-temperature oxidation -- Ni-based single-crystal superalloy -- Atomic diffusion -- Sulfidation -- γ′-depletion -- Grain coarsening and reorientation; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2023.111026
• Languages: English
• ISSNs: 0010-938X

Abstract

Abstract: Early stages of high-temperature oxidation and hot corrosion of Ni-based single-crystal superalloy were studied at 900 °C by introducing sulfate coating. Detailed elemental and microstructural analysis revealed layered surface oxide, atomic diffusion, faceted Al-rich precipitation, and γ′-phase depletion, together with grain coarsening and reorientation in the near-surface region. Undulated surface, multiple layered outer oxide scale, inner CrS scale (solely localized in γ-matrix), and an additional γ′-depleted region without crystal reorientation were observed in hot corrosion rather than in high-temperature oxidation. The corrosion behavior is discussed in terms of atomic diffusion and oxide growth. The impact of sulfate-coating is elucidated. Graphical Abstract: ga1 Highlight: Undulated surface resulted by hot corrosion rather than oxidation of Ni-based SC. Single and multilayer oxides formed in oxidation and hot corrosion, respectively. Al- and Al/Ta-dominant out-diffusions in oxidation and hot corrosion, respectively. Surface reactions drive atomic out-diffusions and, in turn, γ′-phase dissolutions. S modified the oxidation, affected the diffusion, and influenced the reorientation.