Corrosion behaviour of alumina-forming heat resistant alloy with Ti in high temperature steam. (February 2022)

• Record Type: Journal Article
• Authors: Obulan Subramanian, Gokul; Kim, Chaewon; Heo, Woong; Jang, Changheui
• Is Part Of: Corrosion science. Volume 195(2022)
• Publication Date: 2022-02
• Subjects: Alumina-forming alloy -- Steam -- High temperature corrosion -- Pre-oxidation -- Internal oxidation; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2021.110000
• Languages: English
• ISSNs: 0010-938X

Abstract

Abstract: The corrosion behaviour of an alumina-forming heat resistant alloy with high Ti (Fe-35Ni-16Cr-4.5Al-3Ti, wt%) was evaluated in high temperature steam. The alloy developed interfacial α-Al2 O3 layer during the pre-oxidation treatment in air at 750 °C. However, it formed external Cr2 O3 and internal γ-Al2 O3 oxides on the austenite matrix during the steam corrosion at 750 °C for 1000 h. This behaviour is attributed to the increased oxygen permeability into the austenite matrix from the synergistic effect of steam and Ti. Meanwhile, the pre-oxidized alloy with interfacial α-Al2 O3 layer showed improved corrosion protection with reduced weight gain in steam environment. Highlights: Steam corrosion of alumina-forming alloy with high-Ti was investigated. Steam corrosion at 750 °C formed external Cr2 O3 and internal γ-Al2 O3 on austenite. The steam corrosion behaviour was related to the synergistic effect of steam and Ti. Meanwhile, a thinner γ-Al2 O3 layer was developed over the coarse B2-NiAl phases. Pre-oxidized alloy with interfacial α-Al2 O3 showed improved steam corrosion resistance.