A novel design method for NiCr coating against supercritical CO2 via the ReaxFF molecular dynamics theoretical analysis and experimental verification

In order to design a NiCr coating with the strongest corrosion resistance, the corrosion behavior of Ni, Ni10Cr and Ni20Cr coatings was studied using molecular dynamics, in which Ni20Cr coating exhibited the best corrosion resistance. The corrosion behavior of Fe9Cr heat-resistant steel with or without Ni20Cr coating in a supercritical CO2 at 650 ℃ and 15 MPa for 1000 h was carried out by corrosion test, which significantly reduced the experimental period and cost. The Ni20Cr coating was intact and uniform after exposure for 1000 h. A dense and continuous Cr-rich oxide film with low growth stress could rapidly formed on the Ni20Cr coating. The Ni20Cr coating could effectively enhance the corrosion and carburization resistance of Fe9Cr heat-resistant steel.