Effects of Corrosion on the Wear Patterns in Horizontal Slurry Pipelines

Electrochemical techniques have been applied to the study of the effect of corrosion on the wear patterns in a 10 cm diameter pilot plant slurry pipeline carrying a freely settling Newtonion slurry of 20 Vol% 30 to 50 mesh silica sand in water. Comparison of specimens with and without cathodic protection made after periods of exposure from 3 to 6 weeks showed that erosion-corrosion can give very rough surfaces with pitting in the earlier stages later developing into irregular wavy roughening, in contrast to the erosion behavior where hydrodynamically smooth polished surfaces were produced. Electrochemical corrosion rate measurements show that the effect of time on the corrosion component with an abrasive slurry is very much different to that with water where rust films are formed.