Accelerated corrosion of pipeline steel under dynamic DC stray current interference

Abstract

In this paper, the statistical analysis of fluctuation characteristics of pipeline potential under dynamic DC stray current interference was carried out based on field test data. Then a self-designed experimental set-up was applied to study the corrosion behaviour of X70 steel in soil-simulating conditions. The statistical results showed that under the dynamic DC stray current interference, the pipeline potential was periodically fluctuated with dynamic periods between 10 and 300 s. The laboratory experiment results showed that there was a strong correlation between the corrosion rate and the dynamic period. When the dynamic period was less than 300 s, the corrosion rate was less than 22% of the predicted corrosion rate via Faraday's law. Then corrosion mechanism was discussed based on a series of experimental measurment results. The interface capacitance effect, as well as the charge consumption by extra reaction, acted a significant part in depressing metal dissolution under dynamic DC stray current interference.

Experimental research on corrosion behavior of X65 pipeline steel induced by DC interference under cathodic protection

“…The potential of the inflow point of stray current is negative, which can cause the outer corrosion protection layer to peel off when it is serious, and the potential of the outflow point is usually higher than the protection potential, resulting in local electrochemical corrosion of the pipeline. It is an effective way to reduce the interference of stray current by measuring the protection potential of buried pipeline and evaluating the impact on cathodic protection [4][5][6][7]. In this paper, the corrosion behavior of buried steel pipes under DC interference under cathodic protection is studied to explore the effectiveness of cathodic protection system under different circumstances, which is conducive to accurately judging the stray current corrosion problem of buried metal pipes in engineering, improving the effectiveness of cathodic protection system, and formulating reasonable evaluation criteria for stray current corrosion and cathodic protection.…”

Corrosion of steel gas pipe under stray current from electro-osmotic pulse water-proof system

“…Almost all the facilities that were equipped with the ground electrode can be regarded as interference source with different characteristics. Some of the DC interferences are periodically fluctuated in minutes [23]. Some of the directions of the DC currents are changed with the period time of the train moving direction [24].…”

Effect of DC Currents and Strain on Corrosion of X80 Steel in a Near-Neutral Environment

“…Moreover, some studies have shown that stray currents can cause potential shifts and can lead to cathodic protection (CP) failures, which indirectly accelerate corrosion [11,15]. Qin et al [16] found that the potential of X70 steel would periodically fluctuate in soil under a dynamic DC interference. Wang [17] also reported the potential of Q235 steel to shift positively under DC interference, while the corrosion rate increased with the current density.…”