Degradations of Mechanical Properties in Surface Layer and Erosion Resistance of Carbon Steel in Slurries with Different pH and Chemical Compositions

摘要

Effects of anodic dissolution in corrosive slurries with different chemical compositions and pHs on the in-situ surface mechanical properties and slurry erosion resistance of carbon steel are investigated. The experimental measurements indicate that the materials loss rate due to corrosion-enhanced erosion increases linearly with the logarithm of anodic current density. The in-situ nanoindentation shows that the presence of anodic current on surface reduces the surface hardness. Under the galvanostatic control, the erosion rates in acidic slurries are much higher than those in the neutral and alkaline slurries. The exposure to the acidic solutions can also lead to a larger in-situ surface hardness reduction than those than those observed in neutral and alkaline solutions. In the neutral and alkaline corrosive media, the erosion rates and the in-situ surface hardness degradation are hardly affected by the chemical composition of aqueous media. The agreement in the high-to-low order of the in-situ surface hardness and the erosion wastage under the galvanostatic control suggests the corrosion-induced surface mechanical property degradation may play a role in the mechanism of corrosion-enhanced erosion.