Metal corrosion is a major problem in most engineering applications. Corrosion in Marine environments is a part of atmospheric corrosion of metals. This project was carried out to investigate the effect of environmental factors in Sri Lankan coastal area for the uniform corrosion rate of mild steel. The results are used to derive a theoretical equation for the calculation of the theoretical corrosion rate. This project also serves as a part of a large-scale project to create a corrosion map for whole Sri Lanka.
Mild steel samples were exposed to the marine atmosphere for the four month period in four selected coastal areas namely Negombo, Moratuwa, Galle and Tangalle. The samples were collected in every two weeks for the analysis. In addition, passive samples were placed on each place for investigate Sulphur deposition and Salinity of those areas and continuously measured both parameters monthly. The assessment mainly conducted by evaluating the loss of mass of specimens against the time.
Weight loss is the main indication of corrosion rate and it has a relationship with the environmental conditions such as level of Salinity, Sulphur deposition, cumulative rainfall and temperature as following equation.
Weight loss is the parameter of corrosion rate, and it has a relationship with the environmental conditions, such as level of Salinity, Sulphur deposition rate, cumulative rainfall, and temperature.
In this project, efforts were made to find a correlation between corrosion rate and above environmental conditions. An equation was modeled to calculate the corrosion rate if the other parameters are measured or known. This method has the advantage of assessing the corrosion rate of mild steel before actual applications.
Keywords: Uniform Corrosion, Marine Environment, Mild steel, Corrosion rate