LITERATURE REVIEW- 4

In statistical approach to underground corrosion carbon steel pipeline by KOGAS (2001) in field corrosion studies were that performed on polyethylene (PE ) coated carbon steel transmission pipeline laid  underground in Korea, Chemical and biochemical analysis of the soil adjacent to coating defects were performed in both fields on laboratory. The factor controlling corrosion were considered by linear regression analysis,Principal components (PCA) and multiple regression analysis,
The corrosion site had strongly positive correlation with the chemical factors such as low pH and high level of chloride,and anaerobic nature soil that promoted the growth of surface reducing bacteria (SRB). Characterized by low level of soil resistively and reduction - oxidation potential and finally on pipe to soil potential.It was proved that the statistical described results of field and laboratory works satisfactory. Finally the precision equation for the maximum corrosion depth of carbon steel and soil environment is presented. It is important that the chemical,biochemical and cathodic protection (CP) effects should be considered together for the precise prediction of corrosion behaviour i.e the environments.