Evaluation of DC-Subway Stray Current Corrosion With Integrated Multi-Physical Modeling and Electrochemical Analysis

Abstract

Leakage of stray current can cause serious problems by accelerating the corrosion process of a buried pipeline in the subway. A multi-physical finite element model of the DC-subway traction system was established in this study, and the dynamic process of the stray current corrosion on buried pipeline was calculated according to the real time traction conditions. In this study, the corrosion rate variation of stray current is evaluated, and the corrosion trend of stray current is quantitatively calculated. The model simulation shows that the stray current corrosion is significantly higher than other processes during the acceleration process of the subway locomotive. And the potential of the buried pipeline reaches a maximum value when an up-rush of traction current occurs. The corrosion is mainly concentrated in the anode region of the buried pipeline, and the closer the buried pipeline is to the rail the more serious the corrosion is. A corrosion experiment of N20 carbon steel was carried out and verified by finite element model. The results further show that the finite element model can quantitatively calculate and predict the mass loss of buried metal caused by stray current corrosion.

Multi‐state unified calculation model of rail potential and stray current in DC railway systems

“…At present, simulation models of RP and SC are studied by many scholars. In order to analyse the influence of environmental factors, such as soil structure and tunnel structure, on the distribution of SC, scholars build 3D simulation models of DC RS using the object‐based modelling method [6–9]. Lin et al.…”

Effect of Soil Salt Content on Stray Current Corrosion of Buried Metal

“…In addition, various models are established to analyze the law and trend of the buried metal corrosion caused by the stray current. For example, by establishing a multi-physical finite element model of DC metro traction system, the dynamic process of the buried pipeline corrosion caused by stray current is calculated, and the corrosion rate change and corrosion trend of stray current are analyzed [14]. By establishing a segment corrosion calculation model including the track bed structure, the reinforcement corrosion problem caused by DC stray current in the cracked section of the shield tunnel is studied, and the potential distribution and reinforcement corrosion law in the cracked section under different input and output positions are obtained [15].…”

Effect of electrified surface casing on the interference characteristics of stray current generated by deep‐well anode beds

“…Most of these have focused on stray current interference caused by electric railways, urban rail traction systems, electric welding equipment, and high-voltage transmission lines. However, research on stray currents generated by ICCP systems with deep-well anode beds has been limited and has mainly focused on the following two aspects [21][22][23][24][25][26] : (1) The factors influencing stray current interference and (2) the effect of stray current on the protection potential and current distribution along unprotected pipelines. [27] Metwally and Al-Badi [23] discussed the influence of soil conductivity and pipeline polarization on stray current corrosion of unprotected pipelines in the vicinity of the anode bed in a cathodic protection system.…”