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The aim of this paper was to clarify the influence of tensile stress on the electrochemical behavior of X80 steel in a simulated acid soil solution and attempt to understand mechanistic aspects of the corrosion behaviors of X80 under these conditions.

The electrochemical behavior of X80 steel at various tensile stresses was investigated in a simulated acid soil solution using electrochemical impedance spectroscopy, potentiodynamic scan measurements and surface analysis techniques.

The results show that as tensile stress was increased, the open-circuit potential decreased, the reaction activity increase, the reaction resistance (Rct)value became smaller by degrees, the corrosion product film resistance (Rf) first decreased and then increased and polarization current densities changed conversely. The corrosion product film was compact and continuous under the low stress, whereas it was relatively loose under high-stress conditions. Tensile stress promotes the movement of dislocations, which become active points when they move to the steel surface. The increase in the number of active points enhances the anodic dissolution rate and promotes the formation of corrosion product film whose blocking effect can decrease the dissolution rate. The corrosion rate of the specimen is determined by these two effects.

This research provides an essential insight into the mechanism of the electrochemical behavior of X80 steel in acid soil environments.

The purpose of this investigation was to study the erosion-corrosion behavior of ZHMn55-3-1 copper alloy in seawater (flow velocity from 0 to 0.8 m/s, sediment content from 0 to 0.15 percent), to analyze the effects of the flow velocity and sediment content on the erosion-corrosion process.

A simulated erosion-corrosion test system was set up. Weight loss determinations and electrochemical measurements (such as potentiostat square wave (PSW), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization tests) were used to study the erosion-corrosion behavior of ZHMn55-3-1 copper alloy in stagnant and flowing seawater with different sediment contents.

Under the test conditions, ZHMn55-3-1 copper alloys had good corrosion resistance to stagnant clear seawater, while increasing the flow velocity and sediment content reduced the corrosion resistance of the material. The difference in the erosion-corrosion mechanism between flow velocity and sediment content was that the former affected both the cathode process and the anode process of electrochemical corrosion, while the latter essentially affected only the anode process.

This paper explains the effects of flow velocity and sediment content on the erosion-corrosion behavior of ZHMn55-3-1 copper alloy in flowing seawater.

High temperature oxidation and hot corrosion behaviour of some ceramic‐based coatings, e.g. borate, silicate‐chromate and carbide‐oxide on mild steel has been investigated in the temperature range of 400–850°C. The coated steel in general shows much better oxidation and hot corrosion resistance than the uncoated steel specially at higher temperatures. The borate coating has better hot corrosion resistance performance between 700 and 800°C whereas silicate‐chromate is suitable at temperatures above 800°C. The coated steels show parabolic behaviour during oxidation. In presence of Na2SO4, the corrosion rate increases with increasing salt concentration till a maxima is reached. The amount of Na2SO4 corresponding to the maximum corrosion rate decreases with increasing temperature. A self‐sustained fluxing cum sulphidation mechanism has been proposed to explain hot corrosion behaviour of uncoated or coated mild steel.

The purpose of this paper is to investigate the void coalescence and corrosion behaviour of titanium Grade 4 sheets during single point incremental forming (SPIF) process with various spindle rotational speeds. The development of corrosion pits in 3.5 (%) NaCl solution has also been studied during SPIF process.

In this current research work, the void coalescence analysis and corrosion behaviour of titanium Grade 4 specimens were studied. A potentio-dynamic polarization (PDP) study was conducted to investigate the corrosion behaviour of titanium Grade 4 processed samples with various spindle speeds in 3.5 (%) NaCl solution. The scanning electron microscope and transmission electron microscope analysis was carried out to study the fracture behaviour and corrosion morphology of processed samples.

The titanium Grade 4 sheets obtained better formability and corrosion resistance by increasing the CNC spindle rotational speeds. In fact that, the significant plastic deformation affects the corrosion rate with various spindle speeds were recorded.

The spindle rotational speeds and vertical step depths increases then the titanium Grade 4 sheets showed better formability, void coalescence and corrosion behaviour as the same is evidenced in forming limit diagram and PDP curves.

This study aims to investigate the corrosion behavior of cold-rolled Fe₃₅Ni₂₀C_r12Mn_(28-x)Al_x high-entropy alloys (HEAs) using the potentiodynamic polarization technique in 1 M H₂SO₄ acid. Additionally, the influence of molybdenum (Mo) additions as inhibitors and the effect of variations in cold rolling reduction ratios and Al content on corrosion behavior are examined.

Two cold rolling reduction ratios, namely, 50% (R50) and 90% (R90), were examined for the cold-rolled Fe₃₅Ni₂₀Cr₁₂Mn₂₈Al₅ (Al₅) and Fe₃₅Ni₂₀Cr₁₂Mn₂₃Al₁₀ (Al₁₀) HEAs. Mo inhibitor additions were introduced at varying concentrations of 0.3, 0.6 and 0.9 Wt.%. The potentiodynamic polarization technique was used to evaluate the corrosion rates (CRs) under different experimental conditions.

The results indicate that the addition of 0.3 Wt.% Mo in 1 M H₂SO₄ yielded the lowest CR for both R50 and R90, irrespective of the Al content in the HEAs. However, the highest CR was observed at 0.6 Wt.% Mo addition. Furthermore, increasing the concentration of Al resulted in a corresponding rise in the CR. Comparatively, the CR decreased significantly when the cold rolling reduction ratio increased from R50 to R90.

This research provides valuable insights into the intricate relationship between Mo inhibitors, cold rolling reduction ratio, Al content and the resulting corrosion behavior of Fe₃₅Ni₂₀Cr₁₂Mn_(28-x)Al_x HEAs. The comprehensive analysis of corroded HEAs, including surface morphology, compositions and elemental distribution mapping, contributes to the understanding of the corrosion mechanisms and offers potential strategies for enhancing the corrosion behavior of HEAs.

This paper aims to explore the influence of CO₂ partial pressure, flow rate and water cut on N80 steel corrosion behaviors in the displacement process of oil in glutenite reservoir by CO₂ injection.

A self-made 3 L high-temperature and high-pressure autoclave was used to conduct corrosion simulation experiments of N80 steel in different CO₂ partial pressures, flow rates and water cut (the independently developed oil and water mixing approach can ensure the uniform mixing of oil and water in experiments). Techniques like weight loss and surface analysis were used to analyze the corrosion behaviors of N80 steel under different conditions.

Results showed that the average corrosion rate of N80 steel accelerated at varying degrees with the increase of CO₂ partial pressure, flow rate and water cut. Excluding that the samples showed uniform corrosion under the two conditions of 0.5MPa CO₂ partial pressure and static corrosion, they displayed mesa attack corrosion under other conditions. Besides, with the increase of CO₂ partial pressure, the pH value of solution dropped and the matrix corrosion speed rose, hence leading to the increased Fe²⁺ and CO₃²⁻ concentration. Meanwhile, a lowered pH value improved the FeCO₃ critical supersaturation, thereby leading to an increased nucleation rate/growth rate and ultimately causing the decrease of the dimension of FeCO₃ crystallites formed on the surface of the samples.

The results can be helpful in targeted anti-corrosion measures for CO₂/oil/water corrosive environment.

This paper aims to investigate the effect of alternating current (AC) on corrosion, it is not yet clear about the exact mechanism of the corrosion induced by AC. Previous reports indicated that AC corrosion was similar to the effect of continuous cathodic and anodic polarization on the corrosion process of the metals. Wan et al. studied the effect of negative half-wave AC on stress corrosion cracking behavior and mechanism of X80 pipeline steel in near-neutral solution.

This study attempted to understand the AC-induced corrosion by imposing the half-cycle AC on the X80 pipeline steel in an acid bicarbonate solution. The AC corrosion mechanism was determined by weight loss and potentiodynamic polarization curve measurements, as well as surface characterization.

The results show that the positive half-cycle AC accelerated the uniform corrosion in the NaHCO3 solution, the negative half-cycle AC would decrease the uniform corrosion and local corrosion was increased and some Ca and Mg deposited on the surface of X80 steel, so the corrosion rate decreased by negative half-cycle AC. The corrosion product was composed of α-FeOOH under the application of positive half-cycle AC. The oxygen reduction led to a local increase of pH near the electrode surface and led to the formation of α-FeOOH, which enhanced the protectability of corrosion products.

Researchers studied the effect of negative half-wave AC on stress corrosion cracking behavior and mechanism of X80 pipeline steel in near-neutral solution. However, the AC behavior and corrosion mechanism in acid solution are unknown. So to make clear about the corrosion behavior of metals in different polarization states and the mechanism involved, diode technology was used to research the AC corrosion, half-wave AC was applied on the metals after the full-wave rectified.

The main purpose of this study was to investigate the corrosion behaviour of simulated archaeological iron in Cl⁻, NO₃⁻ and HSO₃⁻ bearing pollutants.

Periodic wet‐dry test, potentiodynamic polarization experiments and surface tension tests were used to study the rule of corrosion rate. Scanning Electron microscopy with EDAX, stereoscopic microscopy and X‐ray diffraction were also used to identify the corrosion products and mechanism. Weight loss measurement, electrochemical theory, as well as ions adsorption theory and penetration theory were used to explain the different corrosion behaviour.

The experimental results demonstrated that the attack of anodic ions to the metal at the initial corrosion stage showed great agreement with their surface activity. However, as corrosion progressed, the different reaction mechanisms and the penetration effect of anions as well as the characteristics of the corrosion products (intermediate products and final products) begin to control the corrosion process.

The initial corrosion rate was found to show agreement with the surface activity of anions. From a new viewpoint, this paper explains the different corrosion behaviour of Cl⁻, NO₃⁻ and HSO₃⁻ anions to simulated archaeological iron and offers reference to the individual who pursues in corrosion and protection of metal.

The purpose of this paper is to investigate and find out the surface and electrochemical behaviours of twin roll cast (TRC) 8006 aluminium alloy with different thicknesses due to the cold rolling rates after the TRC process.

The 8006 aluminium alloys are mostly used for the food packaging industry, as they are corrosion resistant, lightweight and shapable materials. The present work investigates the surface and corrosion behaviours of 8006 aluminium alloys at different thicknesses. TRC aluminium alloys were cold-rolled at two different reduction rates before investigation. X-ray diffraction (XRD) and energy dispersive spectroscopy (EDX) tests were used to examine the phase and elemental analyses. FE-SEM and 3D profilometry also used to observe surface morphology. Open circuit potential (OCP), potentiodynamic polarization and electrochemical impedance spectroscopy tests (EIS) were carried out to find out corrosion behaviours. The results show that the more cold rolling reduction (CRR), the more corrosion rate and surface affection of the TRC 8006 aluminium alloys.

According to the electrochemical tests (OCP, potentiodynamic polarization test and EIS) and surface morphology results (such as SEM, 3D profilometry and XRD) the more the rolling rate the less the corrosion resistance.

First corrosion behaviour investigation of twin-rolled 8006 Al alloys using electrochemical techniques. First investigation of CRR effects on electrochemical corrosion behaviour of 8006 Al alloys with 3.5 wt.% NaCl solution using EIS. First investigation of 8006 Al alloys as a food packaging material with electrochemical ways.

The purpose of this paper is to investigate the effect of NaCl solution with different concentrations on impact-sliding fretting corrosion behavior of Inconel 690TT steam generator heat transfer tubes.

The optical 3D profiler was used to measure the wear profile and calculated the wear volume. Corrosion behavior was studied using open circuit potential monitoring and potentiodynamic polarization testing. The morphologies and elemental distributions of wear scars were analyzed using scanning electron microscopy and energy-dispersive spectroscopy. The synergism of wear and corrosion was analyzed according to the ASTM G119 standard.

The corrosion tendency reflected by OCP and the corrosion current calculated by Tafel both increased with the increase of NaCl concentration. The total volume loss of the material increased with concentration, and it was known from the synergism that the volume loss caused by corrosion-enhanced wear accounted for the largest proportion, while the wear-enhanced corrosion also made a greater contribution to volume loss than tangential fretting corrosion. Through the analysis of the material morphologies and synergism of wear and corrosion, the damage mechanism was elucidated.

The research findings can provide reference for impact-sliding fretting corrosion behavior of Inconel 690TT heat transfer tubes in NaCl solution with different concentrations.