LAUSR

Abstract The service life of the equipment can be seriously shortened by corrosion, and the heat resistance of the heat exchange surface will increase sharply due to scaling adhesion, which leads to the reduction of heat transfer efficiency. Simultaneously, scaling adhesion and surface corrosion are not simply isolated. Based on the molecular dynamics, the adsorption of different phase calcium carbonate on the alpha-Fe2O3(0 0 1) surface was studied. Results demonstrate that the atoms of the corrosion interface have a greater impact on the adsorption of aragonite-phase calcium carbonate, and the vaterite-phase calcium carbonate is unstable on the corroded surface. With the increase of temperature, diffusion coefficients of calcite, aragonite and vaterite increase correspondingly, and the diffusion coefficient change of calcite is relatively stable. The concentrations of the surface in a descending order are aragonite, calcite and vaterite in turn. The initial densities of adsorbate atoms on the alpha-Fe2O3(0 0 1) surface are 8.03, 8.44 and 9.10 g/cm, respectively. Additionally, the deposition of various crystalline calcium carbonate molecules can be reinforced by the strong intermolecular interaction under high temperature to a certain extent. Further experiment proves that the scaling is prone to deposit on the severely corroded surface and corrosion products can further accelerate the deposition rate of scaling. The amount of aragonite on the mild steel surface is more than that of calcite. And the corroded surface has selectivity to the nucleation of calcium carbonate scaling.