Degradation of mechanical property of corroded water pipes after long service

Abstract

The intention of this paper is to investigate the degradation of mechanical properties of corroded water pipes after long service. The mechanical tests are conducted to quantify the degradation of mechanical properties of corroded water pipes made of cast iron and steel. Various techniques (e.g. SEM, EDS, XRD, 3D scanning) are used for corrosion and material analyses at both micro and macro levels. It is found that there is a significant reduction of mechanical properties of the corroded pipes due to the change of microstructure, and that the reduction of modulus of rupture is more sensitive to the average corrosion pit depth while the reduction of tensile strength is more sensitive to the maximum corrosion pit depth. The findings presented in the paper can contribute to the body of knowledge of corrosion of metal water pipes for their failure assessment and service life prediction after long service.