Photo-electrochemical analysis of passive film formed on X80 pipeline steel in bicarbonate/carbonate buffer solution

Li, D.G.; Feng, Yaorong; Bai, Zhongxiang; Zhu, Jianbo; Zheng, Min

doi:10.1016/j.apsusc.2007.10.036

Cited by 23 publications

(12 citation statements)

References 31 publications

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“…As can be observed in Fig. 7, C −2 shows linear increase behavior with increasing polarization potential at the various film formation potentials of the passive film for X80 pipeline steel, which is in consistent with the theoretical calculation described in another literature [15]. In good agreement with the decreased tendency of capacitance measurements with increasing polarization potential in the DEIS experiment, the slopes of Mott-Schottky plots are positive, indicating that the passive film is an n-type semiconductor.…”

Section: Semi-conductor Properties Of the Passive Filmssupporting

confidence: 92%

Passivation process of X80 pipeline steel in bicarbonate solutions

Zhou

et al. 2011

Int J Miner Metall Mater

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The passivation process of X80 pipeline steel in bicarbonate solutions was investigated using potentiodynamic, dynamic electrochemical impedance spectroscopy (DEIS), and Mott-Schottky measurements. The results show that the shape of polarization curves changes with 3 HCO − concentration. The critical 'passive' concentration is 0.009 mol/L 3 HCO − for X80 pipeline steel in bicarbonate solutions. No anodic current peak exists in 3 HCO − solutions when the concentration is lower than 0.009 mol/L, whereas there are one and two anodic current peaks when the 3 HCO − concentration ranges from 0.009 to 0.05 mol/L and is higher than 0.1 mol/L, respectively. DEIS measurements show that there exist active dissolution range, transition range, pre-passive range, passive layer formation range, passive range, and trans-passive range for X80 pipeline steel in the 0.1 mol/L 3 HCO − solutions. The results of DEIS measurements are in complete agreement with the potentiodynamic diagram. An equivalent circuit containing three sub-layers is used to explain the Nyquist plots in the passive range. Analyses are well made for explaining the corresponding fitted capacitance and impedance. The Mott-Schottky plots show that the passive film of X80 pipeline steel is an n-type semiconductor, and capacitance measurements are in good accordance with the results of DEIS experiment.

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Section: Semi-conductor Properties Of the Passive Filmssupporting

confidence: 92%

Passivation process of X80 pipeline steel in bicarbonate solutions

Zhou

et al. 2011

Int J Miner Metall Mater

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“…2 and 5, the calculated results had a good agreement with the measured ones. Equation (15) derived herein was validated. It was also proved that the SCC behavior was controlled by the film suppressed anodic dissolution mechanism in these circumstances.…”

Section: Electrochemical Criterion For Evaluating the Susceptibility mentioning

confidence: 99%

“…Equation (15) indicated that this criterion was still in the basic form claimed in Ref. [19], but the factor associated with the suppression effect of passive films was incorporated as a modifier.…”

Section: Electrochemical Criterion For Evaluating the Susceptibility mentioning

confidence: 99%

“…If breakdown occurs in passive film, the material will suffer from pitting and SCC. So far, extensive studies [12][13][14][15][16] have been performed to reveal that the existence of various solvated species such as chloride, bicarbonate, and carbonate ions is in close relationship with the film formation process and the properties of the film. This therefore affects the initiation and propagation of the stress corrosion cracks.…”

Section: Introductionmentioning

confidence: 99%

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A New Understanding of Stress Corrosion Cracking Mechanism of X80 Pipeline Steel at Passive Potential in High-pH Solutions

Fan

Liu

Guo

et al. 2015

Acta Metall. Sin. (Engl. Lett.)

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Susceptibilities to stress corrosion cracking (SCC) of X80 pipeline steel in relatively concentrated carbonate/ bicarbonate solutions with different chloride ion concentrations or pH value at a passive potential of -200 mV vs SCE were investigated by slow strain rate tensile test. In order to explore the SCC mechanism and the evaluation criterion for the SCC susceptibility of the steel in passive state, electrochemical measurements were taken. Potentiodynamic polarization curves were obtained at different potential sweep rates, and electrochemical impedance spectroscopy measurements were taken after fast polarization to the passive potential. The effects of chloride ion and pH on SCC behaviors of X80 steel at the passive potential were also discussed. The results showed that the SCC mechanism of X80 pipeline steel was greatly influenced by the passive film formed in these solutions. The SCC behaviors followed the film suppressed anodic dissolution mechanism in these circumstances, because the filming process accounted for a considerable proportion of the overall electrode process. The criteria for evaluating the SCC susceptibility of the steel at passive potential were proposed and validated. Decreasing in the concentration of chloride ion or increasing in pH value resulted in the reduction in SCC susceptibility. The existence of chloride ion greatly lowered the passivation tendency and the film stability, while its concentration determined the dissolution rate of the steel matrix. Higher pH value was responsible for the stable and tenacious passive films and the high repassivation capability. It was also inclined to lower the anodic dissolution rate at crack tips by retarding the cathodic oxygen reduction.

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“…However, in the presence of 20 g/L carbonate, the passive currents were as lowest as 0.1 µA/cm 2 . Transpassivation was at lower 0.7 V versus SCE potentials but the lowest passive currents, among other samples, can be well associated to thicker passive films , where upon dissolution of the big ferrite grains, Fe 3 C acted as an effective anchoring network within which FeCO 3 precipitated. For the 60 K/s HAZ, it exhibited notably the minimum cathodic current densities in all solutions.…”

Section: Resultsmentioning

confidence: 89%

Passivation of HAZs of API‐X100 pipeline steel in bicarbonate‐carbonate solutions at 298 K

Eliyan

Icre

Alfantazi

2013

Materials & Corrosion

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This research explores electrochemical correlations between heat‐affected zones (HAZs), produced by Gleeble© thermal simulation cycles, and their passivation behavior in bicarbonate–carbonate solutions. The investigations were carried out in comparison with the base API‐X100 steel in naturally aerated 0.5 g/L chloride solutions, containing a matrix of bicarbonate and carbonate concentrations at 298 K. The slow 0.05 mV/s potentiodynamic scans revealed that the passivation onsets earlier in proportion with the bicarbonate concentrations, possessing accordingly greater immunity against chloride ions on HAZs cooled at 10 and 60 K/s from 1223 K peak temperature. The HAZs cooled at 10 K/s, particularly in concentrated carbonate solutions, showed the most stable passivation, and the HAZs cooled at 60 K/s showed the lowest cathodic activity regardless of the chemical conditions. −0.1 V, versus saturated calomel electrode, potentiostatic currents and the open‐circuit potentials decreased and increased, respectively, with the carbonate concentration, confirming with the main potentiodynamic polarization results, and a corresponding passivation behavior of the HAZs, regardless of a bicarbonate–carbonate condition, was relatively similar. In contrary to the 60 K/s HAZs, the 10 K/s HAZs showed evidence of growing passive films with time and high charge‐transfer resistance, as measured by the EIS tests.

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Photo-electrochemical analysis of passive film formed on X80 pipeline steel in bicarbonate/carbonate buffer solution

Cited by 23 publications

References 31 publications

Passivation process of X80 pipeline steel in bicarbonate solutions

Passivation process of X80 pipeline steel in bicarbonate solutions

A New Understanding of Stress Corrosion Cracking Mechanism of X80 Pipeline Steel at Passive Potential in High-pH Solutions

Passivation of HAZs of API‐X100 pipeline steel in bicarbonate‐carbonate solutions at 298 K

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