Synergistic Effects of Hydrogen and Stress on Corrosion of X100 Pipeline Steel in a Near-Neutral pH Solution

Abstract

In this work, scanning vibrating electrode technique and local electrochemical impedance spectroscopy measurements were used to investigate the effects of stress and hydrogen on electrochemical corrosion behavior of a X100 pipeline steel in a near-neutral pH solution. The stress distribution on the test specimen was calculated using the finite element method. Results demonstrated that the hydrogen-charging enhances the local anodic dissolution of the steel, contributing to the formation of a layer of corrosion product. However, there is little difference of the charge-transfer resistance between the regions with and without hydrogen-charging due to rapid diffusion of hydrogen atoms throughout the specimen with time. When the local stress concentration is not significant enough to approach the yielding strength of the steel, the steel is still in a relatively stable state, and there is a uniform distribution of dissolution rate over the whole surface of the steel specimen. Although the stress-enhanced activation is not sufficient to result in an apparent difference of current density of the steel, the activation of the steel would activate dislocations, which serve as effective traps to the charged hydrogen atoms. With the increase of hydrogen concentration, the hydrogen-enhanced anodic dissolution becomes dominant.

Synergistic effects of corrosion time and stress on corrosion of casing steel in H2S/CO2 gas wells

“…These results accord with the previous studies. [2][3][4][5][6][7][8][9][10][11][12][13][14] (3) Effect of corrosion time and internal pressure on the equivalent stress of casing inner wall. Figure 7 shows that the equivalent wall stress changes over the corrosion time and internal pressure.…”

“…[1] It has been widely acknowledged that the imposed stress remarkably accelerates corrosion of steel. [2][3][4][5] Moreover, the mechanochemistry effect on steel electrochemical corrosion has been studied in recent years. Bonora et al [6] examined the corrosion behavior of stressed magnesium alloy in a sodium borate solution by electrochemical measurements.…”

Susceptibility of pipe steel of a controllable rolling tо stress-corrosion cracking

“…Depending on the properties of the medium, two types of SCC are distinguished: at high pH [3,4] and near-neutral pH [5,6]. Researchers proved that at high pH SCC proceeds in an intergranular mechanism [7], and at near-neutral pH its nature is transgranular [8].…”

Effects of Molybdenum on HIC Susceptibility in Normalized Pressure Vessel Steels for Sour Service Applications

“…Microstructural banding, which has been observed in finished products, occurs in the slab-alloy centerline segregation that develops during the solidification of steel. Normalized steels used in pressure vessels for sour service applications are highly susceptible to hydrogen induced cracking (HIC) due to the significant frequency or size of non-metallic inclusions, or undesirable volume fractions of banded microstructures [1,[6][7][8][9][10][11][12][13][14][15] or, in some cases, both. Among the possible microstructures that could improve the HIC performance of steels, the polygonal ferrite/ pearlite microstructure is the least desirable.…”