材料期刊网

Cathode distribution on a metal surface, depending on the total length of three-phase boundary per unit area (L (tpb)), is an important factor influencing corrosion behavior of metals in gas/liquid/solid multiphase corrosion systems. The effect of L (tpb) on cathodic oxygen reduction process was first studied by steady-state polarization technique, and the result showed that the cathodic-limiting current densities linearly increased with increasing L (tpb), indicating that the cathode distribution had an important influence on the corrosion behavior of metals. On this basis, a model is developed to establish the correlation between the cathodic-limiting current and L (tpb). In the model, a general expression for the cathodic-limiting current distribution in TPB zone is deduced, and a linear dependence of the total cathodic-limiting current density on L (tpb) is established. The simulation result is in good agreement with experimental data.