A series of underground corrosion tests has been carried out in order to supply corrosion data as well as basis for estimating life of a pipeline transporting raw material gases to a butadiene plant at Yokkaichi-Combinat. The protection procedure of the line was based on the recommendation of Corrosion Prevention Committee, Japan Society for the Promotion of Science.
Total of 144 test pieces was buried near the warf which was considered to be the most corrosive environment in the pipeline area. The coated steel specimens were connected to the cathodically protected pipeline. Some specimens were not cathodically protected.
The seven-year results show among others that cathodic protection is especially effective in reducing corrosion of bare part of coated steel, which otherwise corrodes 5-10times. The tests will be continued up to 20 years.