Experimental studies on the pitting corrosion of low alloy steels in 3.5% NaCl

A new OCC simulate cell has been designed to simulated the autocatalytic process by the occluded corrosion cavity (OCC) on low alloy steel in 3.5% NaCl solution. The effects of geometrical factors of OCC simulated cell have also been discussed. There are two important parameters in OCC which play an important role in localized corrosion process for low alloy steel, the height and diameter of occluded corrosion cavity. The corrosion rate increases with these two parameters. The suitable size of OCC is 3,3 for height and diameter of OCC which can simulate the corrosion tendency of five low alloy steels used as specimen in this experiment. The pitting corrosion rates of low alloy steels have been rank with the cell. The results are in agreement with the corrosion data got by long time immersion test in the sea.