Influence of KCl and HCl on high temperature corrosion of HVAF-sprayed NiCrAlY and NiCrMo coatings

Sadeghimeresht, Esmaeil; Reddy, Liam; Hussain, Tanvir; Huhtakangas, Matti; Markocsan, Nicolaie; Joshi, Shrikant

Abstract

The oxidation performance of NiCrAlY and NiCrMo coatings thermally sprayed by high velocity air-fuel (HVAF) technique has been investigated in a chloridizing-oxidizing environment, with and without a KCl deposit, at 600 °C for up to 168 h. Both coatings protected the substrate in the absence of KCl due to formation of a dense Cr-rich oxide scale. In the presence of KCl, Cl−/Cl2 diffused through a non-protective and porous NiCr2O4 scale formed on NiCrAlY, leading to formation of volatile CrCl3. On the other hand, Mo in NiCrMo stimulated the formation of a more protective Cr-rich oxide scale which increased the corrosion resistance by reducing Cl−/Cl2 diffusion.

Citation

Sadeghimeresht, E., Reddy, L., Hussain, T., Huhtakangas, M., Markocsan, N., & Joshi, S. (2018). Influence of KCl and HCl on high temperature corrosion of HVAF-sprayed NiCrAlY and NiCrMo coatings. Materials and Design, 148, https://doi.org/10.1016/j.matdes.2018.03.048

• Journal Article Type: Article
• Acceptance Date: Mar 20, 2018
• Online Publication Date: Mar 22, 2018
• Publication Date: Jun 15, 2018
• Deposit Date: Apr 9, 2018
• Publicly Available Date: Mar 23, 2019
• Journal: Materials & Design
• Print ISSN: 0261-3069
• Electronic ISSN: 0264-1275
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 148
• DOI: https://doi.org/10.1016/j.matdes.2018.03.048
• Keywords: Thermal spray coating; NiCrAlYNiCrMo; High-velocity air fuel (HVAF); Biomass-/waste-fired boiler; Fireside corrosion
• Public URL: https://nottingham-repository.worktribe.com/output/938748
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0264127518302338