Microstructural and corrosion analysis of Cr3C2-NiCr coatings on T11 boiler steel at 800°C

Purpose This study aims to analyze the hot corrosion behavior of Cr3C2 coatings mixed with varying amounts of NiCr on T11 boiler steel under high-temperature conditions. It evaluates the corrosion resistance of different coatings using thermogravimetric analysis, X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. Design/methodology/approach Cr3C2-NiCr coatings were deposited on T11 steel using the high velocity oxygen fuel method. Samples were exposed to a molten salt environment at 800°C for 50 cycles, and their degradation was analyzed using thermogravimetric analysis, XRD and SEM/energy-dispersive X-ray spectroscopy (EDS). The study was conducted at a single temperature (800°C), requiring further research on long-term exposure and different thermal conditions for broader industrial applications. The findings support the development of corrosion-resistant coatings for boiler steels, potentially reducing maintenance costs, increasing operational efficiency and extending the lifespan of components in high-temperature industrial environments. Enhancing the corrosion protection in power plants supports sustainable development goal (SDG) 7 (affordable and clean energy) by improving energy efficiency, SDG 9 (industry, innovation and infrastructure) by promoting sustainable industrial practices and SDG 12 (responsible consumption and production) by reducing material wastage and environmental impact. Findings All coatings improved corrosion resistance, with 100% Cr3C2 showing the best performance. However, 65Cr3C2-35NiCr exhibited superior corrosion resistance due to oxide and carbide formation, enhancing longevity compared to uncoated T11 steel. Research limitations/implications The study was conducted at a single temperature (800°C), requiring further research on long-term exposure and different thermal conditions for broader industrial applications. Practical implications The findings support the development of corrosion-resistant coatings for boiler steels, potentially reducing maintenance costs, increasing operational efficiency and extending the lifespan of components in high-temperature industrial environments. Social implications Enhancing the corrosion protection in power plants supporting SDG 7 (affordable and clean energy) by improving energy efficiency, SDG 9 (industry, innovation and infrastructure) by promoting sustainable industrial practices and SDG 12 (responsible consumption and production) by reducing material wastage and environmental impact. Originality/value This research provides valuable insights into the corrosion resistance of Cr3C2-NiCr coatings under high-temperature conditions. It highlights the potential of 65Cr3C2-35NiCr coatings for improved performance, offering an innovative approach to enhancing boiler steel durability in extreme environments.