Effect of Corrosion Surface Topography on Fatigue Life of Low-Carbon Steel

Sri Lanka's first research project conducted utilizing fe-safe software by SIMULIA, in the interest area of fatigue life prediction. The field of Metallurgical Engineering associated with the fatigue life of atmospherically corroded structural components has been studied in extensive detail. Most of the researchers in this area have focused on statistical analysis of fatigue strengths of alloy steels and other metals undergone pitting corrosion in a conventional manner. The scope of this work is focused on the fatigue behavior of low carbon steel, exposed to coastal-atmospheric corrosion. The change in surface topography with time, due to atmospheric-corrosion of low-carbon steel is one of the two main areas in this research and other factor is the drop in fatigue strength with changing surface topography. In this research project, effect of surface topography of corroded low carbon steel on their fatigue lives are evaluated with both experimentally and analytically using finite element modelling. The surface topography is evaluated quantitatively, using Scanning Electron Microscopy and a 3D metrology software. The quantitative data obtained on pit geometries are then represented in finite element modelling to evaluate their fatigue lives using fatigue analyzing FEA software. The significance of this work is that it takes into account the surface topography of corroded low carbon steel and helps to explain the difference between simulated and experimentally obtained fatigue strengths of them.