XU Qinglin, WANG Xiangjun, TONG Yude, et al. Mechanochemical coupling model of corrosion electric field[J]. 2021, 53(3): 186-192.DOI: 10.11918/202001040.
In order to study the effect of elastoplastic deformation on the corrosion electric field of ships
a mechanochemical coupling model of corrosion electric field was established by using the solid mechanics and the secondary current distribution modules in the COMSOL simulation software based on the corrosion defect of ship hull surface. Two physical fields were solved by using the sequential solver setup
and the structural stress-strain simulated by the solid mechanics module was coupled to the expressions of equilibrium potential and exchange current density of electrode reaction
which were taken as the boundary conditions of the secondary current distribution module. Results show that the deformation of the hull structure caused the stress concentration at the corrosion defect
and the metal corrosion potential shifted negatively due to the mechanochemical effect. The existence of potential gradient in solution provided driving force for the current flow
thus forming the stress corrosion couple. Moreover
the center of the defect was anode and both sides of the defect were cathodes. When the corrosion defect was elastically deformed
the modulus of corrosion electric field generated by stress corrosion couple was small
while the corrosion electric field increased significantly when the corrosion defect was plastically deformed.