Research on AC corrosion behavior and corrosion product film evolution of X70 steel under the combined action of AC interference and CP

2022 ◽  
pp. 110085
Author(s):  
Yi Liang ◽  
Yanxia Du ◽  
Dezhi Tang ◽  
Le Chen ◽  
Lijie Qiao
Keyword(s):  
Corrosion Product ◽  
Corrosion Behavior ◽  
Corrosion Product Film ◽  
Product Film ◽  
Combined Action ◽  
Ac Interference

scholarly journals Effect of Weld and Surface Defects on the Corrosion Behavior of Nickel Aluminum Bronze in 3.5% NaCl Solution

Metals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1227
Author(s):  
Xu Zhao ◽  
Yuhong Qi ◽  
Jintao Wang ◽  
Tianxiang Peng ◽  
Zhanping Zhang ◽  
...  
Keyword(s):  
Corrosion Product ◽  
Corrosion Behavior ◽  
Early Stage ◽  
Optical Microscope ◽  
Aluminum Bronze ◽  
Nickel Aluminum ◽  
Nacl Solution ◽  
Corrosion Product Film ◽  
Product Film ◽  
Nickel Aluminum Bronze

To study the effect of weld and defects on the corrosion behavior of nickel aluminum bronze (UNS C95810) in 3.5% NaCl solution, the weight loss, X-ray diffraction, optical microscope, scanning electron microscope and electrochemical test of the specimen with weld and defects were investigated. The results show that the presence of weld and defects increases the corrosion rate of bronze. Weld does not change the structure of the corrosion product film, but defects induce a lack of the protective outermost corrosion product in bronze. Weld makes the corrosion product film in the early stage more porous. Defects always produce an increase in the dissolution rate of the bronze.

Corrosion behavior of X80 pipeline steel in oilfield injection water in Eastern China

2021 ◽  
Vol 68 (5) ◽  
pp. 438-448
Author(s):  
Haoping Peng ◽  
Zhaolin Luan ◽  
Jun Liu ◽  
Yun Lei ◽  
Junxiu Chen ◽  
...  
Keyword(s):  
Corrosion Product ◽  
Corrosion Behavior ◽  
Pipeline Steel ◽  
Eastern China ◽  
Immersion Test ◽  
X80 Pipeline Steel ◽  
Content Type ◽  
Corrosion Product Film ◽  
Product Film ◽  
Injection Water

Purpose This paper aims to under the laboratory environment, the corrosion behavior of X80 pipeline steel in oilfield injection water in eastern China was studied by immersion test. Design/methodology/approach First, the corrosion product film was immersed in oilfield injection water and the effect on the corrosion behavior and the corrosion reaction mechanism were constantly observed during this period. The effect was displayed by potentiodynamic polarization curve and electrochemical impedance spectrums (EIS) measurements. Second, scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction were used to observe and test the corrosion product film immersed in the oilfield water for 30 days. Findings The results indicate that the tendency of metal corrosion becomes weaker at an early stage, but strengthened later, which means the corrosion rate is accelerating. Besides, it is indicated by impedance spectroscopy that with the decreasing of the capacitance arc radius, the reaction resistance is reducing in this progress. Meanwhile, the character of Warburg impedance could be found in EIS, which means that the erosional components are more likely to penetrate the product film to reach the matrix. The corrosion product is mainly composed of the inner Fe3O4 layer and outer shell layer, which contains a large number of calcium carbonate granular deposits. It is this corrosion under fouling that produces severe localized corrosion, forming many etch pits on the metal substrate. Originality/value The experiment chose the X80 steel, the highest-grade pipeline steel used in China, to conduct the static immersion test in the injection water coming from an oilfield in eastern China. Accordingly, the corrosion mechanism and the effect of corrosion product film on the corrosion of pipeline steel were analyzed and discussed.

scholarly journals The Effect of Rare Earths Additions on the Microstructure and the Corrosion Behavior of Sn-0.7Cu-0.075Al Solder Alloy

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3731 ◽  
Author(s):  
Wenchao Yang ◽  
Zaixiang Du ◽  
Shuyuan Yu ◽  
Yitai Li ◽  
Junli Feng ◽  
...  
Keyword(s):  
Solder Alloy ◽  
Corrosion Product ◽  
Corrosion Behavior ◽  
Current Density ◽  
Rare Earths ◽  
Corrosion Current ◽  
Corrosion Property ◽  
Vacuum Arc ◽  
Corrosion Product Film ◽  
Product Film

Sn-0.7Cu-0.075Al solder alloy adding with Ce and La had been successfully prepared by applying ball-milling and vacuum arc remelting. The influence of Ce and La on microstructure and corrosion behavior of Sn-0.7Cu-0.075Al solder alloy was investigated. The results showed that Ce (La)-containing solders had refined grains and obvious directional tendency due to the dispersive refiner (CeO2 and La2O3). Electrochemical potentiodynamic curves revealed three different stages of the reaction, including anodic and cathodic processes, prepassivation section, and stable passivation stages. The self-corrosion potential (Ecorr) of alloys with Ce and La addition were a little bit more negative, hardly making a difference on corrosion occurrence. However, the corrosion current density (Icorr) and passivation current density (Ip) decreased by two-thirds and one-half respectively, which indicated a better corrosion resistant after adding rare earths. The recorded micrographs of corroded surface at different polarized points witnessed the formation of corrosion product film both on prepassivation and passivation stage. Moreover, the cross section of corrosion product film showed the coarse, loose film in Sn-0.7Cu-0.075Al solder and adherent, compact film in Ce (La)-containing solders, which further indicated an excellent anti-corrosion property.

scholarly journals Initial Corrosion Behavior of 12Cr1MoV Steel in Thiosulfate-Containing Sodium Aluminate Solution

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1283
Author(s):  
Jingjiu Yuan ◽  
Chaoyi Chen ◽  
Junqi Li ◽  
Bianli Quan ◽  
Yuanpei Lan ◽  
...  
Keyword(s):  
Corrosion Product ◽  
Corrosion Behavior ◽  
Corrosion Current ◽  
Sodium Aluminate ◽  
Corrosion Mechanism ◽  
Alumina Production ◽  
Aluminate Solution ◽  
Corrosion Product Film ◽  
Product Film ◽  
Corrosion Pits

When alumina is produced by the Bayer process with high-sulfur bauxite, the sulfur would strongly corrode the 12Cr1MoV steel made heat exchanger. This study investigated the initial corrosion behavior of the 12Cr1MoV steel exposed to a thiosulfate-containing sodium aluminate (TCSA) solution under the evaporation conditions of alumina production. The obtained corrosion rate equation is V = 6.306·t·exp(−0.71). As corrosion progressed, with the corrosion product film growing, the corrosion current density declines slowly, and the corrosion resistance of the steel is increased. At 1–3 days, the corrosion product film consisted of FeO, Fe2O3, and FeOOH. S2O32− lead to corrosion in local areas of the steel and pits appeared. AlO2− is transformed into Al(OH)3 and filled in the corrosion pits. At 4 and 5 days, Fe3O4 is generated in the outermost layer, and Al(OH)3 is shed from the corrosion pits. The corrosion mechanism of 12Cr1MoV steel in a TCSA solution is proposed based on the experimental results.

Corrosion Behavior of Low-Alloy Steel in COT Upper Deck O2-CO2-SO2-H2S Moisture Environment

2013 ◽  
Vol 652-654 ◽  
pp. 916-922 ◽  
Author(s):  
Jin Ming Liang ◽  
Di Tang ◽  
Peng Cheng Zhang ◽  
Hui Bin Wu ◽  
Hong Yan Mao ◽  
...  
Keyword(s):  
Corrosion Product ◽  
Corrosion Behavior ◽  
Grain Structure ◽  
Low Alloy Steels ◽  
General Corrosion ◽  
Electron Backscattered Diffraction ◽  
Corrosion Product Film ◽  
Corrosion Scale ◽  
Upper Deck ◽  
Product Film

This paper focus on the development of low-alloy anti-corrosion steel for the upper deck of COT(cargo oil tank), and the corrosion behavior of Cr-containing low-alloy steels in O2-CO2-SO2-H2S moisture were studied using homemade COT corrosion simulation device. After the corrosion experiment, related corrosion data was measured, and macro morphology and structure of corrosion scale were observed by SEM(Scanning Electron Microscope). The phase and chemical composition of corrosion product film were analyzed by XRD(X-ray diffraction) and EDS(energy dispersive spectroscopy). The effect of misorientation distribution on anti-corrosion property of steel was investigated by EBSD(electron backscattered diffraction). Based on the results, corrosion scale of COT on the upper deck consist of α-FeOOH, γ-FeOOH, FeS2, S and Fe1-xS, and the type of corrosion is mainly general corrosion. Cr enrichment was found on the inner corrosion product film, the addition of Cr leads to the increasing of low-angle grain boundaries and sub-grain structure which is conducive to the improvement of corrosion resistance.

scholarly journals Evolution of the Corrosion Product Film on Nickel-Aluminum Bronze and Its Corrosion Behavior in 3.5 wt % NaCl Solution

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 209 ◽  
Author(s):  
Yang Ding ◽  
Rong Zhao ◽  
Zhenbo Qin ◽  
Zhong Wu ◽  
Liqiang Wang ◽  
...  
Keyword(s):  
Corrosion Product ◽  
Aluminum Bronze ◽  
Protective Film ◽  
Nickel Aluminum ◽  
Nacl Solution ◽  
Corrosion Attack ◽  
Corrosion Product Film ◽  
Product Film ◽  
Nickel Aluminum Bronze

The in-situ studies of the corrosion product film on nickel-aluminum bronze are significant for explaining the mechanism of its corrosion resistance. In this paper, the corrosion behavior of nickel-aluminum bronze and the formation process of the protective film in 3.5 wt % NaCl solution are systematically investigated. The results of scanning electron microscope analysis and electrochemical tests indicate that the corrosion resistance of nickel-aluminum bronze is improved due to the formation of the corrosion product film. The change of local electrochemical property on the corrosion product film during the immersion time is evaluated via in-situ scanning vibrating electrode technique, and it reveals the evolution rules of ionic flux in real time. The formation process of the protective film on different phases in nickel-aluminum bronze is observed directly by in-situ atomic force microscopy as height change measurements. The α phases at different locations present different corrosion behaviors, and the lamellar α phase within the α + κIII eutectoid structure gets more serious corrosion attack. The κ phases establish a stable and dense protective film in short time, preventing the corrosion attack effectively. The β′ phase, however, suffers the most serious corrosion damage until a protective film is formed after 150 min of immersion.

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