Corrosion Product Film Research Articles

Electrochemical corrosion behavior of aluminum conductor under current-carrying condition in a simulated atmospheric environment

Purpose The purpose of this paper is to study the corrosion behavior of aluminum under the current-carrying condition. It aims to investigate the corrosion electrochemical characteristics of aluminum under the influence of the applied electric current and the self-generated magnetic field. Design/methodology/approach To study the influence of the current-carrying condition, a home-made electrochemical device was used to analyze the kinetic characteristics of the atmospheric corrosion of aluminum by means of potentiodynamic polarization, electrochemical impedance spectroscopy and chronoamperometry. Scanning electron microscopy and X-ray diffraction were used to investigate the morphological characteristics and main phase compositions of corrosion products. Moreover, the atmospheric corrosion mechanism of aluminum under current-carrying condition was analyzed. Findings The passage of a direct current (DC) through a metal conductor generates a self-generated magnetic field. The presence of this magnetic field accelerates the diffusion of oxygen, thereby accelerating the electrochemical cathodic reaction. The corrosion products film, under the influence of the electric current, exhibit a loose and layered structure, which facilitates the intrusion of Cl− and accelerates the corrosion of aluminum. Research limitations/implications The research on the atmospheric corrosion of aluminum in the power grid may not fully cover the complex and variable environmental factors. For example, in the actual atmospheric environment, there are comprehensive influences such as the temperature fluctuations between day and night. Practical implications This study provides theoretical guidance for predicting the service life of metal components in the power transmission grid under working conditions. Originality/value In the investigation of aluminum’s atmospheric corrosion, the influences of the applied DC current and the self-generated magnetic field were introduced for the first time.

Behavior of compounds on the corrosion of ZK61-xCe magnesium alloys

Abstract The corrosion kinetics and the influence of Ce content on the corrosion performance of ZK61-xCe (x = 0, 0.5, 1.0, 1.5, wt%) magnesium alloys in NaCl (0.1 mol l−1) solution were investigated using hydrogen evolution tests combined with observations of corrosion morphology. The role of compound on the corrosion of the alloy was analyzed based on changes in the microstructure, electrode potentials of compounds and matrix, and electrochemical properties of the corrosion product film. The results show that the corrosion rate of the experimental alloy is faster in the first 3 h, then the corrosion rate is gradually reduced, and the corrosion process fits the power-exponential dynamics equation. The corrosion rate constants k and exponential n in the corrosion kinetic equations first decrease and then increase with the increase of Ce content, with the Ce content is 0.5wt%, the alloy has the slowest corrosion rate and the best corrosion resistance. The corrosion rate of the alloy is controlled by the micro-galvanic corrosion. After adding Ce to the ZK61 alloy, the MgZn2 in the alloy is converted to (Mg, Zn)12Ce with more negative electrode potential, and the electrode potential decreases from −0.811 V to −1.002 V. The electrode potential of the α-Mg matrix in the alloy is about −1.451 V, and the potential difference between the compounds and the α-Mg matrix decreases, the corrosion driving force of micro-galvanic corrosion decreases, and the corrosion resistance increases. With the increase of Ce content, the amount of (Mg, Zn)12Ce compounds increases, resulting in an increased number of micro-galvanic couples, increased migration charge density, and decreased corrosion resistance. As the corrosion proceeds, the number of (Mg, Zn)12Ce exposed on the surface of the substrate increases, blocking the contact between the substrate and the corrosion medium, himpeded lateral corrosion propagation and longitudinal corrosion extension of the α-Mg matrix.

Advancements in prediction models for corrosion in oil and gas pipelines

Abstract Oil and gas pipelines play an important role in the energy transportation industry, but metal corrosion can affect the safe operation of pipeline equipment. This study uses CiteSpace software to synthesize and analyze corrosion models and keywords from research institutions, countries, and methods related to pipeline corrosion prediction. The investigation into the mechanisms of pipeline metal corrosion, with a specific emphasis on CO 2 and H2S corrosion, has revealed that several factors influence the process, including temperature, partial pressure, medium composition and the corrosion product film. In addition, the study provides a comprehensive review of pipeline corrosion prediction methods and models. These include traditional empirical, semi-empirical, and mechanism-based prediction models, as well as advanced machine learning techniques such as random forest, artificial neural network model, support vector machine, and dose-response function. Although there are many ways to improve model performance, no universally accepted methods have been established. Therefore, further in-depth research is needed to improve the accuracy of these models and provide guidance for improving the operational safety of pipelines.

In Situ Spectroscopies Unraveling the Molecular Mechanisms of H+ and Cl- on Pyridine Inhibition of Low-Carbon Steel Corrosion.

This study utilized a variety of in situ spectroscopic techniques to investigate the corrosion inhibition mechanism of three pyridine-based inhibitors on carbon steel in HCl and NaCl solutions. The results demonstrated that the adsorption and orientation of the inhibitor molecules play key roles in the corrosion inhibition mechanism studied using second harmonic generation (SHG). The number density of molecules adsorbed on the substrate is a crucial factor affecting the inhibition efficiency. A two-step physical model elucidates the SHG signal time evolution, revealing initial rapid inhibitor adsorption and subsequent slow dynamic adsorption optimization. Our research indicated that, in HCl solution, H+ protonates the pyridine inhibitors, and the protonated species adsorb onto the positively charged substrate bridging, forming a compact chemisorbed layer that effectively blocks corrosive ion access. In contrast, in NaCl solution, Cl- promotes the formation of a porous corrosion product film, which synergizes with adsorbed inhibitors to mitigate metal degradation. This finding offers insights into molecular-level interfacial inhibition mechanisms in environments with H+ and/or Cl- ions.

Improving corrosion resistance of copper-nickel alloys by the microalloying-facilitated formation of protective corrosion product films

Improving corrosion resistance of copper-nickel alloys by the microalloying-facilitated formation of protective corrosion product films

Effects of corrosion product films on hydrogen embrittlement sensitivity of X70 steel under dry-wet cycle conditions

Effects of corrosion product films on hydrogen embrittlement sensitivity of X70 steel under dry-wet cycle conditions

Revisiting the corrosion characteristics of B30 copper-nickel alloy under complete seawater exposure and crevice corrosion conditions: A comprehensive TOF-SIMS study of corrosion-product films

Revisiting the corrosion characteristics of B30 copper-nickel alloy under complete seawater exposure and crevice corrosion conditions: A comprehensive TOF-SIMS study of corrosion-product films

Microstructural Optimization and Erosion-Corrosion Resistance of Cu-10Ni-3Al-1.8Fe-0.8Mn Alloy via Tailored Heat Treatment.

This study systematically investigated the effects of tailored heat treatments on the microstructural evolution, mechanical properties, and erosion-corrosion resistance of Cu-10Ni-3Al-1.8Fe-0.8Mn alloy. Four heat treatment conditions-as-cast (AC-1); homogenized (H-2); and deformation-aged at 500 °C (D-3) and 750 °C (D-4)-were applied to elucidate the interplay between microstructure and performance. The D-3 specimen, subjected to deformation followed by aging at 500 °C for 0.5 h, demonstrated superior properties: a Vickers hardness of 118 HV5 (83.3% higher than H-2) and an erosion-corrosion rate of 0.0075 mm/a (84.1% reduction compared to H-2). These enhancements were attributed to the uniform dispersion of nanoscale Ni3Al precipitates within the matrix, which optimized precipitation strengthening and reduced micro-galvanic corrosion. The D-3 specimen also formed a dense, crack-free Cu2O corrosion product film with a flat matrix interface, confirmed by SEM cross-sectional analysis and electrochemical impedance spectroscopy (EIS), exhibiting the highest charge transfer resistance and film impedance.

Impact of types of water source on pipeline corrosion: a comprehensive electrochemical and microscopic analysis

ABSTRACT Switching water sources is essential for effective water resource management and pipeline maintenance, ensuring water supply stability and reducing reliance on a single source. However, improper water source selection can disrupt the chemical balance within pipelines and accelerate corrosion. This study simulated the process of switching water sources and employed electrochemical analysis, such as scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy, to investigate the impact of water source switching on pipeline corrosion. During the initial switching phase, severe pipeline corrosion was observed, along with significant variations in water quality indicators that substantially influenced corrosion. Electrochemical analysis revealed a decrease in pipeline open circuit potential and a negative shift in the polarization curve, indicating an increased tendency for corrosion. Corrosion could be relieved as the pipeline adapted to the new water quality. Microscopic analysis demonstrated that switching water sources affected the structure and stability of the corrosion product film. Investigations into different water source switching ratios indicated that corrosion levels should not be evaluated based on a single parameter; an appropriate blend of water sources is necessary to effectively mitigate corrosion. This study provides valuable insights for water source management, pipeline maintenance, and efficient water supply strategies.

Study on Pitting Behavior of Welding Joint of Bimetal Composite Pipes in Suspended Sulfur Solution

Due to the severe corrosion environment, corrosion problems caused by sulfur deposition are one important reason for the failure of composite pipes in the long-term service process when Incoloy825/X65 bimetallic composite pipes are used in high-sulfur oil and gas transportation. In this paper, an Incoloy825/X65 bimetallic composite pipe was subjected to an immersion corrosion test in suspended sulfur solution to observe the corrosion morphology and characterize the corrosion products using a SEM, EDS, and XRD. The adsorption behavior of the Incoloy825 alloy in terms of sulfur elements was investigated. The results show that the heat-affected zone (HAZ) of the welding joint is the preferred region for pitting corrosion. The film of corrosion product on the Incoloy825 was mainly composed of NiS, FeS, and Cr2S3, and its thickness was 7–13 μm. With prolongation of the immersion time, the pitting resistance of the surface product film of nickel-based alloys is weakened and then enhanced, and the corrosion product film can act as a barrier to anion transfer and inhibit the occurrence of pitting.

Effect of Hydrodynamic Conditions on the Corrosion Mechanism of HSLA X100 Steel by EIS and EN Analysis

In this research work, the influence of the electrolyte hydrodynamic conditions on the corrosion mechanism of the high-strength low-alloy (HSLA) X100 steel used in the petroleum transportation pipelines was analyzed. A Rotary Cylinder Electrode (RCE) was used to simulate the hydrodynamic conditions (1000 and 5000 rpm). Mechanical, microstructural and elemental characterization tests were performed on X100 steel, and the electrochemical impedance spectroscopy (EIS) technique was used to analyze the corrosion mechanism, while the morphology of the corrosion process on the corroded surfaces was obtained by scanning electronic microscopy (SEM). It was found that the increasing rotation rate (υ rot) generates a fully developed flow regime where the system was dominated by a mass transfer process and increases the kinetics of chemical and electrochemical reactions so there is an increase in the corrosion rate (CR). On the other hand, the adsorption of corrosion product films that limits the charge transfer process depended on the magnitude of the shear stress that can generate wear and roughness, as well as a greater number of anodic sites, leaving the metal exposure to the corrosive medium.

Corrosion behavior of Cu-containing 3Ni steel in simulated marine environments with different NaCl concentrations

PurposeThis study aims to investigate the corrosion behavior of Cu-containing 3Ni steel in simulated marine environments and to provide basic guidance for improving the corrosion resistance of marine high-strength steels.Design/methodology/approachThe corrosion properties of Cu-containing 3Ni steel were evaluated in five different NaCl concentrations by alternating wet and dry cycling method. The corrosion behavior was investigated by electrochemical impedance spectroscopy, scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The mechanism of the influence of Cl ion concentrations on the corrosion behavior of Cu-containing 3Ni steel in marine environments was analyzed.FindingsThe results showed that the corrosion resistance of Cu-containing 3Ni steel decreased with NaCl concentration increasing. With the increase of NaCl concentration, the number of FeOOH particles decreased and their size increased, resulting in an increase in the porosity and a decrease in the density of corrosion products. High NaCl concentration could inhibit the formation of NiFe2O4 and disrupt the electronegativity of the inner film of corrosion products, which further weakened the enrichment of Ni and Cu, and enhanced the permeability of Cl ions.Originality/valueThe influence of NaCl concentrations on the corrosion behavior of Cu-containing 3Ni steel was systematically studied and the influence laws of corrosion behavior were obtained in this paper, providing basic data for the optimal design of Cu-containing 3Ni steels.

Mechanistic study of aluminum alloy corrosion under the interaction of Embellisia sp. and Candida xyloterini.

Microorganisms and their cultural traits significantly affect the service performance and durability of materials. Currently, research on the corrosion mechanisms of microorganisms affecting aluminum alloys primarily focuses on bacterial corrosion, with fewer studies addressing the corrosion behavior and mechanisms caused by fungi. This study investigated the corrosion behavior of aluminum alloys under the interaction of two fungi, Embellisia sp. and Candida xyloterini, as well as their composite systems. Electrochemical impedance analysis revealed that both fungi inhibited the corrosion of aluminum alloys, with the degree of inhibition ranking in descending order as follows: Embellisia sp., mixed systems, and C. xyloterini. The main reasons for the inhibition of corrosion were the aerobic nature of the two fungi and the formation of a composite membrane structure on the metal surface, which consisted of both the corrosion product film and the biofilm. Fungal growth curves indicated that the co-culture led to a reduction in the number of fungi, resulting in a decrease in biofilm density and resistance to corrosive ions. Consequently, the two fungi exhibited an antagonistic effect in inhibiting the corrosion of aluminum alloys.

Enhancing corrosion resistance of Mg-Al-Mn-Ca-Y dilute alloy via novel core-shell structured Al8Mn4Y-Al2Ca and controllable solute segregation

Enhancing corrosion resistance of Mg-Al-Mn-Ca-Y dilute alloy via novel core-shell structured Al8Mn4Y-Al2Ca and controllable solute segregation

Influence of trace Sc on microstructure and corrosion behavior of Mg-0.5Zn alloys

PurposeThis paper aims to explore the impact of Sc element on the microstructure and corrosion properties of Mg-0.5Zn alloy.Design/methodology/approachThree kinds of Mg-0.5Zn-xSc (x = 0.1, 0.3 and 0.5 Wt.%) alloys were obtained, and the microstructure and corrosion properties were both analyzed.FindingsAs the Sc concentration increases, the corrosion resistance of the alloys initially improves and subsequently deteriorates. The trace addition of Sc can effectively reduce the grain size of Mg-Zn-Sc alloys and enhance the density of the corrosion products film. Consequently, an appropriate amount of Sc can reduce the corrosion rate of Mg-0.5Zn alloy.Originality/valueHowever, the addition of Sc also introduces the second phase particles in the alloy, leading to galvanic corrosion, which adversely affects the corrosion resistance of Mg-0.5Zn alloy. Therefore, the amount of Sc added should be carefully controlled.

Effect of Mg content on corrosion resistance of Zn-11Al-XMg coatings

Zn-Al-Mg is one of the most important coating types in hot dipped galvanization. This surface coating also provides surface barrier protection and galvanic protection, which improves the esthetics and service life of the material. In this paper, the corrosion resistance of Zn-11Al-XMg coatings with Mg content (wt. %) of 0, 1, 2, 3 was studied, and the effect of Mg content on the corrosion resistance of Zn-11Al-XMg coatings was analyzed. The results show that Zn-11Al coating is composed of an eutectoid Al-rich phase and a Zn-rich phase. When the Mg content is less than 2 wt. %, the increase of Mg content is accompanied by the decrease of the Al-rich and Zn-rich phases and the increase of the ternary eutectic content. When the Mg content is more than 2 wt. %, the increase of Mg content is accompanied by the decrease of the ternary eutectic content and the increase of the primary MgZn2 phase content. The results of corrosion experiments show that the Zn-11Al-XMg coating is mainly composed of an Al-rich phase and an Mg2Zn11 phase in ternary eutectic as the main anode. The coating after adding Mg forms a denser corrosion product film, among which the Zn-11Al-2Mg coating close to the eutectic point has the best corrosion resistance.

STUDY ON THE CORROSION RESISTANCE OF HOMOGENEOUS Mg-1Bi-0.5x (x=Nd,Ce,La) ALLOYS

Mg alloys are widely used in the aerospace and automotive industries, as well as in electronic products due to their low density and high specific strength. However, the poor corrosion resistance of Mg alloys limits their applications. Rare earth elements have been shown to improve the corrosion resistance of alloys. In this study, Mg-1Bi-0.5x (x = Nd, Ce, La) alloys were prepared by alloying with Bi, Nd, Ce, and La. The microstructure and corrosion behavior of Mg-1Bi-0.5x (x = Nd, Ce, La) alloys were investigated using X-ray diffraction (XRD), optical microscopy (OM), scanning electron microscopy (SEM), hydrogen evolution tests, weight loss experiments, and electrochemical measurements. The results indicate that the Mg-1Bi-0.5Nd alloy exhibits higher corrosion potentials and lower corrosion current densities, indicating superior corrosion resistance. This improvement is attributed to the formation of a more stable and uniform film of corrosion products, which prevents further corrosion and enhances corrosion resistance.

Effect of microstructure evolution on the corrosion behavior of extrusion-shearing Mg-3Zn-XCa-0.6Zr alloys

Effect of microstructure evolution on the corrosion behavior of extrusion-shearing Mg-3Zn-XCa-0.6Zr alloys

Investigation of corrosion behavior of 5Cr steel in CO₂-silty sand environment: Effects of hydrodynamic impact angles

Investigation of corrosion behavior of 5Cr steel in CO₂-silty sand environment: Effects of hydrodynamic impact angles

Study on the Effect of Dry and Wet Cycle Time Ratio on the Corrosion Behavior of 2198 Aluminum–Lithium Alloy

ABSTRACTThe corrosion of 2198 aluminum–lithium alloy in a marine atmospheric environment was simulated using a wet–dry alternating experimental setup. Weight‐loss measurement methods, electrochemical impedance spectroscopy (EIS), scanning electron microscopy/energy‐dispersive spectroscopy (SEM/EDS), macroscopic morphology testing, three‐dimensional morphology testing, and X‐ray photoelectron spectroscopy (XPS) were used to study the wet–dry alternating corrosion behaviors and mechanisms of 2198 aluminum–lithium alloys under simulated marine atmospheric environment. The results indicate that corrosion weight loss increases with decreasing wet‐to‐dry ratios, accompanied by an increase in the corrosion rate. Various data suggest that the primary corrosion products are composed of Al2O3, AlO(OH), and AlCl3. The reduction in the wet‐to‐dry ratio leads to the enrichment of Cl⁻ within the corrosion products, extending the contact time between the substrate and the medium, thereby intensifying the hydrolysis of Al³⁺. This exacerbates the dissolution at pitting sites, which in turn erodes and breaks down the corrosion product film, accelerating the overall corrosion process.