Effect of temperature on corrosion behaviour of X70 steel in high pressure CO₂/SO₂/O₂/H₂O environments

Abstract

The corrosion study of the pipeline steel is extremely important for the safety of CO 2 pipeline. The present work studied the effect of temperature on the corrosion behaviour of X70 steel in high pressure CO 2 /SO 2 /O 2 /H 2 O mixtures. Weight loss method was utilised to measure the corrosion rate. Environmental scanning electron microscopy and focused ion beam technology were employed to observe the morphology of product scales. X-ray diffraction was used to analyse the composition of product scales. The porosity of product scales was measured, and the exhaust gas was detected by gas chromatography. Results showed that the corrosion rate increased with the increasing temperature and then started to decline with temperature with the peak corrosion rate at 348 K. Results also showed that there was hydrogen that existed in the exhausted gas, indicating that the hydrogen evolution reaction was contained in the corrosion cathodic process.

Internal corrosion of carbon steel pipelines for dense-phase CO2transport in carbon capture and storage (CCS) – a review

“…However, Xiang et al [84] have utilised focused ion beam etching to look into the structure of a spherical FeSO4 corrosion product (shown in Figure 6(d)). Observations from the etching process revealed that small micro-pores existed within the crystalline film, but these were not connected and 27…”

“…In general, three typical corrosion morphologies are reported in literature; a thin sulphur-rich cracked film [27,78,82,83] (Figures 6(a), (b) and (c)), columnar/spherical crystals of FeSO3/FeSO4 [4,78,84] (Figures 6(d), (e) and (f)), and globular crystals of FeCO3 [78,81] …”

Impact of surface roughness and humidity on X70 steel corrosion in supercritical CO 2 mixture with SO 2 , H 2 O, and O 2

“…Apparently, hydrated ferrous sulfate (FeSO 4 ·xH 2 O) are the main composition of product films. In contrast, Hua et al [44] pointed out that hydrated ferrous sulfite (FeSO 3 ·xH 2 O) are the main composition of product films that are exposed to water-saturated CO 2 phase at 35 °C and 8 MPa containing different concentration levels of The reaction mechanisms associated with the formation of FeSO 4 in this work have been pointed out by Xiang et al [8,17] and Choi et al [21]. The possible reaction mechanisms that include anodic and cathodic reactions are as follows:…”

“…In the past several years, carbon steel corrosion in supercritical CO 2 with water, oxygen, SO 2 , and other impurities has received increasing attention [6,8,[10][11][12][13][14][15][16][17][18][19][20][21][22][23]. Several studies have focused on corrosion in liquid CO 2 [20,24,25] and the CO 2 capture process [26,27], which are beyond the focus of this paper.…”

Long term corrosion of X70 steel and iron in humid supercritical CO2with SO2and O2impurities

“…[1][2][3] However, most of the existing studies focused on the uniform corrosion behaviour of metals in supercritical CO 2 environments, while in practical CO 2 pipeline transport, localised corrosion, which usually needs a long period to form and develop, is more harmful to the operation safety. The transformation mechanisms of corrosion products under long term condition are also not clear.…”