Influence of Chloride Ions on Corrosion of Modified Martensitic Stainless Steels at High Temperatures Under a CO₂Environment

Abstract

The influence of chloride ion concentration on the passivation film and corrosion product film of martensitic stainless steels (SS) (13% Cr, modified 13% Cr-1% Mo, modified 13% Cr-2% Mo, and 15% Cr SS) have been investigated using immersion tests and electrochemical measurements in sweet environments at temperatures of 150°C and 180°C in the presence of carbon dioxide (CO 2 ). The corrosion rate of conventional 13% Cr SS was found to increase with increasing chloride ion concentration at 150°C. However, the corrosion rates of modified 13% Cr SS and 15% Cr SS were independent of the chloride ion concentration at 150°C. The corrosion rates of modified 13% Cr SS increased with increasing chloride ion concentration above 1,000 ppm at 180°C. The corrosion rate of 15% Cr SS slightly increased at high chloride ion concentration at 180°C. Chromium-enriched corrosion product films were produced on all alloys considered, except for 15% Cr SS, at 180°C. A passivation film was maintained for 15% Cr SS at 180°C. In addition, the pitting corrosion behaviors were investigated by potentiodynamic polarization curves and open-circuit potential measurements. The behavior of the current density of anodic curves corresponded to the immersion test results. Pitting corrosion on modified 13% Cr-2% Mo SS is considered to repassivate because of low potential compared with pitting potential. KEY WORDS: CO 2 corrosion, high temperature, immersion test, martensitic stainless steel, modified martensitic stainless steel, pitting potential ISSN 0010-9312 (print), 1938-159X (online)

Formation and Evolution of the Corrosion Scales on Super 13Cr Stainless Steel in a Formate Completion Fluid With Aggressive Substances

“…Figure 14 compares the measured corrosion rate in the formate fluid (tubing outer wall and casing) with those obtained from the literature both in formate fluid and formation water (tubing inner wall) (Leth-Olsen, 2004;Sunaba et al, 2014;Zhao et al, 2018;Qi et al, 2019;Yue et al, 2020b). It reveals that S13Cr shows a lower corrosion rate in the formate fluid than that in formation water.…”

Corrosion Behavior of 316L Stainless Steels Exposed to Salt Lake Atmosphere of Western China for 8 years

“…8b. Cr(OH) 3 can be regarded as an unstable structure, which cannot improve the corrosion resistance, leading to the reduced protectiveness of corrosion products and pitting resistance according to the previous researches [34,35]. However, the relative amount of [Cr ox ] in corrosion products formed on stainless steels gradually increased as a function of exposure time.…”

The development of a mechanistic-chemometrics model with multi-degree of freedom for pitting corrosion of HP-13Cr stainless steel under extremely oilfield environments

“…It can be seen that the maximum pit depth gradually decreased with the increase in flow rate within the range of 0.31-1 m/s. Furthermore, the growth kinetics of pits was fitted using Equation (10), and the results show that the value of K decreased from 4.86 to 3.70 when the flow rate increased from 0.31 m/s to 1 m/s. The decrease in growth rate of the pit was mainly attributed to the vortex generated inside the pit, where the distribution of H + and metal ion was inhomogeneous [15].…”

“…Nesic et al [11] reported that temperature and CO2 pressure accelerate the pitting corrosion by the electrochemical, chemical, and transport processes. Additionally, the effect of temperature and CO2 pressure on the pitting corrosion has been studied on passive films and corrosion scales [6,9,10,[12][13][14][15]. The results illustrate that the enhanced pitting susceptibility of HP-13Cr SS can be attributed to the effects of temperature and CO2 pressure on the microstructure and composition of corrosion scales [14].…”

“…HP-13Cr stainless steel (SS) is widely used as an OCTG in oil industry, as they offer improved CO2 corrosion resistance in relation to carbon steels, and offer lower costs than the duplex SS grades or Ni alloys [6][7][8][9][10]. However, the inspected field results have revealed that HP-13Cr SS suffers severe pitting corrosion.…”