Abstract
To test new materials and coatings, accelerated corrosion is providing an estimate of the corrosion resistance, protection and evolution. Although the variation of the liquid film thickness and the concentrations of the solutes in the film play a significant role in corrosion processes, little modelling has been done on this subject. Knowing the thickness in every point on the surface would lead to a better understanding of the different processes involved in the corrosion of the metal.
Firstly, a model to predict the time dependent film thickness is presented based on condensation and evaporation processes. The focus being on test chambers, the effect of heat radiation is neglected. The corrosion rate is assumed to be driven by oxygen reduction.
Secondly, using this model, a parameter study is performed by doing three-dimensional simulations on sample plates as used in real experimental tests. The influences of the film thickness and NaCl concentration variation on the corrosion rate are studied as a function of geometrical (surface area, thickness), material (density, thermal properties) and environmental (temperature, relative humidity, fluctuation speed of temperature and relative humidity, heat and mass transfer coefficient) data.
