The superhydrophobic coating with low‐temperature dew point corrosion resistance on an acid‐resistant steel substrate prepared by the electrodeposition method

Abstract

The acid-resistant steel represented by 09CrCuSb (ND) steel that is widely used in flue gas treatment systems is easily prone to mixed-acid dew point corrosion in the low-temperature flue gas environment. To improve the corrosion resistance of ND steel in a low-temperature dew point corrosion environment, here, a chromium-myristate hybrid (CMH) superhydrophobic coating is proposed as a low-temperature dew point corrosion protective coating for the ND steel substrate. This superhydrophobic coating is deposited on the ND steel substrate (preplated dark nickel as a transition layer) by onestep direct current electrodeposition. The electrochemical analysis from potentiodynamic polarization and electrochemical impedance spectroscopy and the immersion test show that the CMH superhydrophobic coating can significantly improve the corrosion resistance of the ND substrate. Therefore, the present study provides a feasible strategy for preventing the mixed-acid dew point corrosion of ND steel in the low-temperature zone.chromium-myristate hybrid superhydrophobic coating, dew point corrosion, direct current electrodeposition | INTRODUCTIONAt present, fossil fuels such as coal and petroleum are still the main energy sources used in power, metallurgy, and other industrial applications. [1] With the higher requirements of energy conservation and emission reduction, the fuel flue gas needs to be treated at a lower temperature (lower than 80°C), [2] which leads to a more severe mixedacid (sulfuric acid and hydrochloric acid) dew point corrosion problem. In recent years, some low-alloy steels that are designed by adding a small amount of alloy elements on the basis of ordinary carbon steel composition system have been applied to achieve the sulfuric acid dew point corrosion resistance of flue gas treatment systems. [3,4] However, under such a mixed-acid dew point corrosion environment, it will be more difficult to improve the corrosion resistance of acid-resistant steel by further adding alloying elements. Therefore, it is very important to find other suitable treatment methods to further improve the corrosion resistance of acid-resistant steel.Recently, a superhydrophobic coating with a micronanostructure and low surface energy prevented the