Effect of electric-arc-induced ablation on corrosion behavior of pipeline steel under high-voltage direct current interference

Purpose - The purpose of this study is to elucidate the effects of electric-arc-induced ablation on the corrosion behavior of pipeline steel in neutral and high pH environments. Design/methodology/approach - Electrochemical testing, an atmospheric-pressure immersion experiment and various techniques (e.g. scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy) were used to examine the effects of electric-arc-induced ablation on the corrosion behavior of pipeline steel in neutral and high pH environment. Findings - Electric-arc-induced ablation occurred preferentially in areas of inclusion. The corrosion resistance of an ablation pit was lower than that of non-ablation areas. In the neutral soil solution, general corrosion was the dominant corrosion that affected pipeline steel; the effect of ablation was small but pitting corrosion could still be induced. In a high pH environment, the samples without ablation were passivated, whereas the samples with ablation pits could not be passivated; the ablation pits were likely to develop pitting corrosion. Originality/value - Electric-arc-induced ablation can reduce the corrosion resistance of pipeline steel under high-voltage direct current interference.