Corrosion of high tensile steel onboard bulk carrier loaded with coal of different origins

A sudden increase in bulk carrier losses in the early 1980s caused considerable alarm in the shipping industry. This paper presents corrosion rate models for the structural components of high tensile steel (HTS) and demonstrates corrosion as affected by various factors determining the microclimate in the holds. For specimens buried in coal from Australia and Indonesia, the difference in mass loss was similar and almost negligible. Average corrosion rates for all specimens under various stress levels vary nonlinearly over time, especially during the first 48 h. Regarding the corrosion rates of specimens, generally the corrosion rates of specimens under the same stress in Australian coal were slightly higher than those of specimens in Indonesian coal between 48 and 240 h. The corrosion levels for most HTS specimens did not correspond to the ranking of stress levels they suffered throughout the experiment. The mass loss for specimens in Indonesian and Australia coal under stress levels other than 95% was similar at 2 h and 96 h. The pattern of corrosion that has been observed for steel in sand and soil also occur for fine-particle coal in this investigation. The corrosion rates of HTS covered by both coals were highly dependent on the quantity of water contents.