Effect of Cation Types on the Steel Corrosion Inhibition Behavior of Calcined Layered Double Hydroxides in Saturated Calcium Hydroxide Solution

It is important to study the steel corrosion inhibition behavior in complex chloride salt environments. This paper uses the fact that calcined layered double hydroxides (CLDHs) have a certain memory effect, which means that it can reabsorb water and anions and partially restore the lamellar structure under certain conditions. This work investigated the influence of cation types on the steel corrosion inhibition behavior of CLDH in saturated calcium hydroxide solution using equilibrium isotherms of ${\mathrm{Cl}}^{-}$ uptake, the electrochemical method, X-ray diffraction (XRD), Fourier-transform infrared (FTIR), and scanning electron microscopy (SEM) techniques. The results show that the corrosion inhibition of the CLDH is affected by the cation types in the following order: ${\mathrm{Ca}}^{2+}>{\mathrm{Mg}}^{2+}>{\mathrm{K}}^{+}\approx {\mathrm{Na}}^{+}·{\mathrm{Na}}^{+}$ and ${\mathrm{K}}^{+}$ increase the pH of the solution and decrease the corrosion inhibition of CLDH. The addition of ${\mathrm{Mg}}^{2+}$ can promote the reconstruction of Mg-Al-Zn-Cl hydrotalcite. The addition of ${\mathrm{Ca}}^{2+}$ can promote the formation of new Ca-Al layered double hydroxide (Ca-Al-LDH) and improve the corrosion inhibition.