Atmospheric corrosion is generally considered to be slow and mild. But it occurs widely in metal materials exposed to the atmosphere, which generates enormous economic losses yearly and may even cause catastrophic accidents1. Thus it is of great significance to explore the dynamics of atmospheric corrosion and establish models for precise prediction of its behavior.According to the electrochemical theory of metal corrosion, atmospheric corrosion is essentially an electrochemical process under a thin electrolyte film, including the dissolution of the metal and oxygen reduction. The thickness of the film affects the oxygen diffusion rate and further impacts the oxygen reduction reaction rate on the metal/electrolyte interface. The porous corrosion products not only partly cut down the electrode surface activity of metals but also increase the paths for oxygen diffusion. And they can change significantly with the composition of the materials and the serving environment. Therefore, it is particularly crucial to study the influence of electrolyte film thickness and corrosion product porosity on atmospheric corrosion.University of Science & Technology Beijing’s National Center for Material Service Safety researchers Wenchao Li, Jiangshun Wu, Yujie Qiang & Ying Jin, Sweden’s KTH Royal Institute of Technology’s School of Engineering Sciences in Chemistry, Biotechnology & Health’s Division of Surface & Corrosion Science Wenchao Li & Jinshan Pan and Beijing Institute of Space Launch Technology’s Kangning Liu & Qinglin Lian in research paper published in Nature “Numerical simulation of carbon steel atmospheric corrosion under varying electrolyte-film thickness and corrosion product porosity” said “A finite element model is developed to study dynamics of atmospheric corrosion of carbon steel, focusing on the influence of thin electrolyte film thickness under varying corrosion product porosity. Calculations have been done to evaluate the impact of electrolyte film thickness and corrosion product porosity on oxygen diffusion path, and the hindrance effect of corrosion products on the metal surface activity. The time evolution of corrosion current density and controlling steps in the corrosion process are explored. When the corrosion products are loose, oxygen diffusion is the dominant controlling step, and the thicker the electrolyte film, the lower the corrosion rate. When they are dense, the corrosion process is controlled by the mixture of oxygen diffusion and the surface discharge. The oxygen diffusion path is determined only by the corrosion product porosity, and therefore the corrosion rate is not affected by the electrolyte film thickness.”
Atmospheric corrosion is generally considered to be slow and mild. But it occurs widely in metal materials exposed to the atmosphere, which generates enormous economic losses yearly and may even cause catastrophic accidents1. Thus it is of great significance to explore the dynamics of atmospheric corrosion and establish models for precise prediction of its behavior.According to the electrochemical theory of metal corrosion, atmospheric corrosion is essentially an electrochemical process under a thin electrolyte film, including the dissolution of the metal and oxygen reduction. The thickness of the film affects the oxygen diffusion rate and further impacts the oxygen reduction reaction rate on the metal/electrolyte interface. The porous corrosion products not only partly cut down the electrode surface activity of metals but also increase the paths for oxygen diffusion. And they can change significantly with the composition of the materials and the serving environment. Therefore, it is particularly crucial to study the influence of electrolyte film thickness and corrosion product porosity on atmospheric corrosion.University of Science & Technology Beijing’s National Center for Material Service Safety researchers Wenchao Li, Jiangshun Wu, Yujie Qiang & Ying Jin, Sweden’s KTH Royal Institute of Technology’s School of Engineering Sciences in Chemistry, Biotechnology & Health’s Division of Surface & Corrosion Science Wenchao Li & Jinshan Pan and Beijing Institute of Space Launch Technology’s Kangning Liu & Qinglin Lian in research paper published in Nature “Numerical simulation of carbon steel atmospheric corrosion under varying electrolyte-film thickness and corrosion product porosity” said “A finite element model is developed to study dynamics of atmospheric corrosion of carbon steel, focusing on the influence of thin electrolyte film thickness under varying corrosion product porosity. Calculations have been done to evaluate the impact of electrolyte film thickness and corrosion product porosity on oxygen diffusion path, and the hindrance effect of corrosion products on the metal surface activity. The time evolution of corrosion current density and controlling steps in the corrosion process are explored. When the corrosion products are loose, oxygen diffusion is the dominant controlling step, and the thicker the electrolyte film, the lower the corrosion rate. When they are dense, the corrosion process is controlled by the mixture of oxygen diffusion and the surface discharge. The oxygen diffusion path is determined only by the corrosion product porosity, and therefore the corrosion rate is not affected by the electrolyte film thickness.”
