Corrosion-induced multiscale damage behavior of ultrahigh strength steel: An integrated simulation and experiment study

Abstract

Corrosion is an aggravating problem to cause the premature failure of structure materials, ultimately impacting the safety and operational expenses of equipment. However, the corrosion-induced multiscale damage evolution in the ultrahigh-strength steel is not clearly revealed from atomic scale to macroscopic scale. Here, corrosion-induced multiscale damage mechanism of ultrahigh strength steel plate is investigated using the experiments combined with multiscale simulation, including molecular dynamic simulation, cellular automaton simulation, and phase field finite element method. The experiment shows that the high angle grain boundaries are particularly vulnerable to corrosion, grain refinement takes place during the process of corrosion, and the exposed surface displays significant cracks in the surface of plate. From molecular dynamic simulation, the thickness of the passivation film and the corrosion rate go up with the increasing temperature, which accelerates the early passivation. The corrosion-induced cracks promote the local healing of surface roughness, leading to low strain softening at the nanoscale. By cellular automaton simulation, the passivation film, formed by the corrosion products, serves to hinder the anodic dissolution of the matrix, thereby reducing the average depth of the corrosion pits. Through phase field finite element simulation, the concentration of local strain plays a crucial role in accelerating the rupture rate of the passive film and increasing the corrosion rate at the tip of a pit. Additionally, strong local strains have a significant impact on the longitudinal advancement of corrosion, leading to the progression from a corrosion pit to a crack. These findings not only give a deep understanding of the corrosion-induced cracking behavior, but also provide valuable insights for the development of steel plate with enhanced mechanical properties.