Corrosion Behavior Analysis of Various Ions in the Soil to the X80 Buried Pipeline

Abstract

Abstract：Through physico-chemical analysis of soil under the buried pipeline, the corrosion influence factor of different ions such as 、 、 and on X80 has been studied. The result shows that when the ions concentration of 、 、 increases, the corrosion rate of X80 steel also rises and then reaches the maximum. After that, the corrosion rate begins decreasing. While for the case of ions, the corrosion rate of X80 steel keeps increasing with the concentration increase. Through detail analyzing the corrosion mechanism of different negative ions on buried pipeline steel and studying the soil corrosion rules, we can provide theoretical basis for the corrosion preventing work, which is very important and meaningful.

Research Advances of Soil Corrosion of Grounding Grids

“…Liu et al found that the severity of stainless-steel corrosion varies with the chloride concentration through corrosion exposure experiments, and the corrosion potential has a linear relationship with the logarithm of the chloride concentration [ 78 ]. The higher the chloride concentration in the soil, the more corrosive the soil, which has been confirmed in many studies [ 11 , 54 , 79 , 80 , 81 ]. Karimian et al found that in the soil can be used as a catalyst to participate in the oxidation of iron and promote the corrosion process [ 82 ].…”

“… has an important influence on the corrosion of carbon steel. can generate with and combine with the sand in the soil to form a strong protective layer, which effectively inhibits the anodic process of corrosion and slows down the corrosion of carbon steel [ 11 , 54 , 80 ]. The cations such as , , and in the soil mainly play a conductive role and do not directly affect the electrode process of soil corrosion, so they have little effect on soil corrosion.…”

“…On May 25, 2005, due to the aging and partial corrosion of the transformer grounding line in the southern part of Moscow, Russia, all 321 substations of the Moscow power grid were shut down, and as a result, the industrial production, commercial activities, and transportation in about half of Moscow city were paralyzed [ 10 ]. In 2008, the neutral point potential of a 330-kV substation in Northern Xi’an, China, increased abnormally, and the DC system was destroyed, causing a large-scale blackout [ 11 ]. After inspection, it was found that the cause of the accident was the internal corrosion of the grounding grid, and the neutral point could not be grounded normally.…”