Analysis of Influence Factors for Buried Corroded Flushing Carbon Steel Pipeline Under Multiple Loads

Abstract

Corrosion was one of the main factors that caused the failure of buried pipelines. In this paper, the buried flushing carbon steel pipeline with external corrosion defect was taken as the research object, considering the nonlinear characteristic of pipe-soil contact, and the nonlinear variation of soil temperatures changed with buried depth, the finite element model of pipeline was established with solid element. Then, the corroded pipeline subjected the multiple loads of gravity, internal pressure, temperature difference and soil force, the key part of which strength was calculated. Meanwhile, how the ambient temperature, relative corrosion depth and operating pressure influenced on pipeline strength were discussed respectively. The results showed that: there was a reverse increasing trend between the environment temperature and the equivalent stress of corroded pipeline; the equivalent stress of pipeline increased when the relative corrosion depth and operating pressure increased; when the three types of influence factors were considered synthetically, from July to September was the best time to do the flushing work for the flushing pipeline with acceptable defect.