An Investigation of Corrosion of Tinplate Oil Cans During Transportation

摘要

The current study deals with failure analysis of tinplated steel cans which were used to store soya oil. Approximately 1700 such cans were transported in two closed containers to the market. Total duration of transport was 96 h. During unloading, 600 cans filled with soya oil were found to be rusted from outer sides except top and bottom. Such rusting is undesirable because can loses its aesthetic value. No cases of rust were reported when cans were transported in open trucks. A detailed investigation of the cause of corrosion of tinplate steel cans was carried out. Site visit observations, microscopic study and SEM-EDS analysis were carried to reach the conclusion. After identifying the cause of corrosion, simulation setup was developed to verify the appearance of rust in five different environments and it was correlated with actual rusted samples. Study concluded that use of partially wet grass as a cushion inside the closed container, during transport of oil cans, facilitated the corrosion of cans and the presence of chloride in the atmosphere aggravated this effect.