Corrosion Localization Analysis in T-Shape Pipe Junction Based on Multielectrode Current Measurements

Georgii Vasyliev

doi:10.1155/2020/7267808

Abstract

The water flow rate and galvanic current distribution in the T-shape junction of steel pipes were investigated using the multielectrode array approach. The inner surface of polypropylene pipes junction was divided into 15 separate sections, and a steel plate was placed in every section to form a single inner surface. The tap water flow rate varied between 0.28 and 0.57 m/s, and the water distribution in the junction was between 5 : 1 and 1 : 5. The galvanic current flowing through each steel electrode was mapped on the 3D model of the T-shape junction. Two differential aeration pairs were found with high anodic current densities.

Highlights

Water distribution networks for domestic and industrial needs, manufactured from steel pipes, are vulnerable to internal corrosion
Change in the flow rate leads to the different oxygen supply causing the formation of differential aeration galvanic couples between parts of the surface with dissimilar flow rate [6, 7]. e operation of anodic region of galvanic couple accelerates metal dissolution and even leads to the penetration of the pipe wall within a short period
Low oxygen supply under the covered part of the surface resulted in the formation of the anodic region, while the remaining surface acted as a cathode

Summary

Introduction

Water distribution networks for domestic and industrial needs, manufactured from steel pipes, are vulnerable to internal corrosion. E application of multielectrode allowed the establishment of the surface distribution on anodic and cathodic regions as well as the current values flowing through each electrode. When water flow rate in two regions is different, this may cause the formation of the aeration galvanic cell.

Results

Conclusion