Polarization Resistance Method Research Articles

Determination of the probability and rate of corrosion on reinforced concrete specimens through a remote corrosion monitoring system

In this paper, we present the design and construction of a remote monitoring system for determining the probability and rate of corrosion of rebar embedded in concrete. We use the ASTM standard C876 technique for the probability of corrosion and the Linear Polarization Resistance method to indirectly obtain the rate of corrosion. The system consists of a communication module using GSM and GPRS cellular networks which provide remote measurements. The device was used to evaluate corrosion with reference electrodes of copper/copper sulfate and graphite on Type I Portland cement specimens of 15cm in diameter and 30cm in length. The results of the measurements were compared to a commercial system, revealing similar values to the data obtained in the field and the laboratory.

Influence of the quality and uniformity of ceramic coatings on corrosion resistance

Pre-treated stainless steel substrates were dip-coated with yttria-doped zirconia, and the quality of the coatings was studied by a newly proposed non-destructive method, comparing the results with those obtained with other techniques. The objective was to analyze the effect of the coating׳s quality on the corrosion rate. To this end, the corrosion rate was determined by means of the linear polarization resistance method. The results showed coatings deposited on the polished substrate at a withdrawal rate of 25mmmin−1 to be the most uniform and homogeneous, and to present the best resistance to corrosion.

Corrosion Characteristics of Transit Pipeline API 5L X60

The paper deals with the determination of corrosion rate to the natural gas pipeline API 5L X60 in Trnava region. Linear polarisation resistance method (exposure time 1 hour) was used for investigation the corrosion rate of exposed samples in the environment (top, middle and lower part of soil excavation and distilled water). The corrosion rate was also determined by measuring the weight loss of the steel samples. The exposure time for the measurement method of the weight loss of metallic materials accounted 120, 288, 528 hours. These outputs helped to identify the most suitable environment for the tested metallic material. Top and middle part of soil excavation was situated in the least aggressive environment. On the other hand, the lower part of soil excavation was situated in the most aggressive environment for API 5L X60.

Flow Assisted Erosion-Corrosion of High Speed Steel (HSS) in Nanofluid Coolant

The use of nanocoolant is suspected to have effects on erosion-corrosion of piping systems in heat exchanger. This study was carried out to determine the erosion corrosion of AISI 316 stainless steel in solutions containing nanoparticles. The experiments used rotating cylinder electrode (RCE) at rotational speed of 0-1800 rpm under varying temperature of 30oC-70oC. Corrosion rate was measured using linear polarization resistance (LPR) method and erosion was indicated by measuring average depth of surface of the samples (surface roughness). The results showed that both corrosion rate and surface roughness of samples have increased when temperature and rotation speed increased. The erosion-corrosion effects of nanocoolant were lower in stagnant condition. Comparing with conventional coolant, the nanofluid showed significant differences. In flow conditions, the effects were remarkable. It was also found that maximum synergism erosion and corrosion were occurred at higher temperature and high rotation speed for both of types solutions.

Corrosion protection of non-alloyed AIAI 316L concrete steel metal grade in aqueous H2SO4: Electroanalytical and surface analyses with Metiamide

The inhibitive ability of an imidazoline-derived compound, Metiamide (N-methyl-N′-(2-{[(4-methyl-1H-imidazol-5-yl)methyl]thio}ethyl)thiourea) – MTA – on non-alloyed AIAI 316L concrete steel metal grade (MS) corrosion in 0.5M H2SO4 solution has been evaluated in this study using Electrochemical impedance spectroscopy, Potentiodynamic polarization and Linear polarization resistance methods. The inhibitor protected MS by inhibiting its corrosion rate in the acidic medium and the inhibition efficiency (I%) increased with the concentration of the inhibitor. The adsorption behaviour of MTA inhibitor has been explained with respect to impedance data. Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM) characterizations for surface morphological studies complemented the electrochemical studies. This work is designed to study the protection of non-alloyed concrete iron steel used in acid service environment with an organic corrosion inhibitor.

Comparative Inhibition Effect of Synthesized Fatty Amides Mixture, Pyridine and Pyrrole on Carbon Steel in Saline Environment

The inhibition effect of synthesized fatty amides mixture, pyridine and pyrrole as corrosion inhibitors on carbon steels in saline water had been compared using Linear Polarization Resistance Method (LPRM). It is still unknown which of these organics performed best than another. The experimental results showed that the inhibition effect of the synthesized fatty amides mixture is found to be better than pyridine and pyrrole, indicating the presence of various chain lengths of fatty amides molecules. These molecules provide a better surface on carbon steels than pyrrole and pyridine.

Effect of Ohmic Drop on Accuracy of Reinforcement Corrosion Rate Measured Using Different Setups

Abstract High resistance offered by concrete to the current applied to polarize reinforcing bars embedded in concrete during measurement of reinforcement corrosion rate results in Ohmic drop, which causes inaccuracy in the measured value of the reinforcement corrosion rate. A study on accuracies of a simple developed setup and two other commercially available setups in measuring reinforcement corrosion rate using the linear polarization resistance method with and without Ohmic drop compensation is reported in this paper. The good correlation between electrochemically measured corrosion current density and gravimetrically measured percentage weight loss was taken as an indicator of accuracy of each setup. The developed setup was found to be most accurate in measuring corrosion rate without, as well as with, Ohmic drop compensation. Both commercial setups were found to have reasonably acceptable accuracy without Ohmic drop compensation; however, both were found with unacceptable accuracy with Ohmic drop compensation.

Corrosion Resistance Characteristics of Zn-Ni/Sio2 Composite Coatings

Composite electrodeposits of Zn-Ni/SiO 2 were produced electrolytically using direct current. Their corrosion resistance characteristics were investigated through the use of neutral salt spray, linear polarisation resistance and potentiodynamic anodic polarisation methods. Neutral salt spray data shows that times to 5% red rust were longer for the coatings embedded with SiO 2 particles than those without particles. Effect of current density shows that deposits produced at higher current densities consistently exhibited a tendency to decrease in corrosion resistance. In addition, the linear polarisation resistance of coatings containing SiO 2 tends to increase with increasing particle content up to 5.5wt% SiO 2 and then decreases. However, there was no significant difference observed for the anodic dissolution current densities for coatings containing SiO 2 particles and their SiO 2-free counterparts. The mode of protection appears to be a combination of sacrificial and barrier protection to the underlying steel substrate

A study of the anticorrosion properties of carbonate deposits to protect low-carbon steel from the action of tap water

Effect of electrochemically injected magnesium ions on the process in which carbonate deposits are formed on a corrodible surface of low-carbon steel in water of heat-and-water supply systems was studied. It was found that the anticorrosion efficiency of the deposit, evaluated by the polarization-resistance method and voltammetry, is approximately 1.5 times that of natural deposits formed in the absence of injected magnesium ions. X-ray diffraction analysis with grazing beam incidence, scanning electron microscopy, and energy-dispersive analysis demonstrated that mostly dense polycrystalline calcium carbonate deposits with a structure of aragonite are formed in the presence of magnesium ions. The mechanism by which a protective CaCO3 layer grows on the corrodible surface of low-carbon steel is discussed.

Study of steel corrosion inhibition in media containing H2S and CO2 by impedance spectroscopy and polarization resistance methods

Summary Inhibition of carbon steel corrosion by “INCORGAS” compositions in a NACE medium containing hydrogen sulfide and carbon dioxide was studied by electrochemical impedance spectroscopy and linear polarization resistance methods. Contribution of the inhibitor to the total protective effect of the “corrosion product film/inhibitor” system was calculated. Polarization measurements testify that the anodic process is hindered in the presence of the inhibitors. The same conclusion was made from the data of electrochemical impedance spectroscopy.

144 微分分極抵抗法による球状黒鉛鋳鉄の腐食特性評価(材料力学・機械材料)

144 微分分極抵抗法による球状黒鉛鋳鉄の腐食特性評価(材料力学・機械材料)

Tannic acid as corrosion inhibitor for metals and alloys

Reduction of environmental impacts caused by pollution harmful to metals and alloys is very important. The atmospheric corrosion is a serious problem due to economic and environmental losses. Thus it is important to properly prevent corrosion phenomena. Tannic acid is one of natural, non‐toxic, and environment friendly inhibitors of corrosion. The inhibitive action of tannic acid was investigated using linear polarization resistance method. The corrosion parameters: corrosion potential and current as well as polarisation resistance, were determined. Corrosion rate and inhibitive efficiency was calculated for two series of tested samples (metals and alloys). An inhibitive effect of tannic acid concentration and immersion number in tannic acid solution on metal and alloys corrosion was described. Copper appeared to be the most resistant metal to corrosion in the presence of tannic acid. Higher inhibitive efficiency of tannic aid was observed in the case of Inconel 625 alloy than steel due to higher content of Cr and lower content of Fe.

Corrosion Inhibitor Performance with Presence of FeCO<sub>3</sub> Film in CO<sub>2</sub> Corrosion Environment under Fluid Flow Effect

Corrosion due to carbon dioxide (CO2) has a major impact on the oil and gas industry by severely affecting production and process facilities. One of the most economic methods to prevent the corrosion of piping and plants is the application of corrosion inhibitors. The presences of corrosion product such as iron carbonate (FeCO3) film may affect to the performance of corrosion inhibitor. In addition to that, fluid flow effect in pipeline may also influence the performance of corrosion inhibitor. Thus, the present work is conducted to study the effect of FeCO3 film to the performance of imidazoline based corrosion inhibitor under fluid flow effect. The experiments were done in glass cells at 80°C. The hydrodynamic condition experiment was simulated using rotating cylinder electrode (RCE). Corrosion inhibitor was added at two different concentrations in the iron carbonate film formation. A corrosion rates were measured by linear polarization resistance (LPR) method. The film was later analyzed using scanning electron microscopy (SEM). It was found that a better corrosion protection is still offered by corrosion inhibitor even with presence of FeCO3 film. A synergistic effect is offered by these two films of corrosion inhibitor and FeCO in reducing corrosion rate.

Corrosion Inhibitor Performance with Presence of FeCO<sub>3</sub> Film in CO<sub>2</sub> Corrosion Environment under Fluid Flow Effect

Corrosion due to carbon dioxide (CO2) has a major impact on the oil and gas industry by severely affecting production and process facilities. One of the most economic methods to prevent the corrosion of piping and plants is the application of corrosion inhibitors. The presences of corrosion product such as iron carbonate (FeCO3) film may affect to the performance of corrosion inhibitor. In addition to that, fluid flow effect in pipeline may also influence the performance of corrosion inhibitor. Thus, the present work is conducted to study the effect of FeCO3 film to the performance of imidazoline based corrosion inhibitor under fluid flow effect. The experiments were done in glass cells at 80°C. The hydrodynamic condition experiment was simulated using rotating cylinder electrode (RCE). Corrosion inhibitor was added at two different concentrations in the iron carbonate film formation. A corrosion rates were measured by linear polarization resistance (LPR) method. The film was later analyzed using scanning electron microscopy (SEM). It was found that a better corrosion protection is still offered by corrosion inhibitor even with presence of FeCO3 film. A synergistic effect is offered by these two films of corrosion inhibitor and FeCO in reducing corrosion rate.

A simultaneous screening of the corrosion resistance of Ni–W thin film alloys

A range of Ni–W thin film alloys have been synthesised by evaporation from atomic sources to produce a compositional gradient across the substrate, and characterised by X-ray diffraction (phase identification and crystallite size) and EDX (composition). The corrosion resistance of 100 discrete alloy compositions has been measured simultaneously in identical environments using a high-throughput screening protocol based on cyclic voltammetry. The corrosion resistances and potentials are extracted from potentiodynamic data by both the linear polarisation resistance (LPR) and Tafel extrapolation methods; results from these are shown to be self-consistent. The high-throughput approach allows, for the first time, a direct correlation to be made between the bulk crystalline phases and morphology, and the corrosion behaviour of Ni–W alloys. The incorporation of W in the Ni–W solid solution at low W compositions results in a continuous reduction in crystallite size, a small cathodic shift in corrosion potential, and a small reduction in corrosion resistance. A large cathodic shift in corrosion potential together with a significant increase in the corrosion resistance is observed for alloy compositions greater than 24%at.W. This composition range coincides with the formation of the amorphous phase.

Effect of Multipasses on Microstructure and Electrochemical Behavior of Weldments

Shielded metal arc welding was applied to AISI 1045 medium carbon steel. The microstructural changes and electrochemical corrosion behavior of the heat-affected zone (HAZ), base metal (BM), and weld zone (WZ) were investigated. The effect of welding passes on microstructural changes of BM, HAZ, and WZ were elucidated using optical microscopy, potentiodynamic Tafel scan, and linear polarization resistance (LPR) methods in plain water and 3.5 pct (w/v) NaCl solution under standard temperature and pressure using corrosion kinetic parameters. From microstructural observations, the variations in ferrite morphology in the BM and WZ showed dissimilar electrochemical corrosion behavior and a corrosion rate than that of HAZ.

Inhibitory activity of fluorine-containing quaternary ammonium salts comprising an N-methylpiperazinyl moiety

New fluorine-containing quaternary ammonium salts comprising an N-methylpiperazinyl moiety, which exhibited a high inhibiting capacity against hydrochloric acid corrosion of low-carbon steel, were synthesized. The polarization-resistance method was applied to determine the uniform corrosion rate of steel-3 in relation to the structure and concentration of the fluorine-containing substituents in the salts. It was found that the structure of the fluorine-containing moiety of the quaternary ammonium salts does not significantly influence the corrosion processes.

A method for inhibiting scale formation and corrosion in a cooling water system

The polymeric inhibitors made show promise inhibiting corrosion and scale formation in the recirculating cooling water system. In this paper, polymer blends were prepared by mixing an anionic polymer, poly(acrylic acid) and polyaniline dispersion. The blends have been evaluated for their effectiveness to retain the dissolved minerals in the cooling water and to protect carbon steel against corrosion in alkaline recirculating cooling water conditions. Monthly water analyses have been conducted on makeup and recirculating cooling waters in the presence of the new treatment, and the active chemical components were monitored. Stressed system conditions have been established by increasing the temperature (15–50°C) and cycles of concentration (1.5–4.5 cycles) to perform a series of scales and corrosion tests. The results obtained from these studies show that the present polymer blends used at 100 ppm concentration have an inhibiting effect on the calcium and magnesium scales up to 91 and 82%, respectively. The weight loss and corrosion polarization resistance method (Corrater system) measurements were carried out to investigate the ability of polymer blends to inhibit within the aqueous system the corrosion of carbon steel. An inhibition efficiency of nearly 81% is achieved for 100 mg/L concentration of polymer blends.

Thermo-electrical properties in Pb-Sb hypereutectic alloy

Pb-17 wt% Sb hypereutectic alloy was directionally solidified upward with three different growth rates (8 μm/s, 18 μm/s, 42 μm/s, 166 μm/s and 497 μm/s) at a constant temperature gradient (3.6 K/mm) in the Bridgman-type growth apparatus. The dependence of characteristic microstructure parameters such as primary dendrite arm spacing (λ1) and secondary dendrite arm spacing (λ2) on the growth rate (V) were determined by using a linear regression analysis. Variations of electrical resistivity (ρ) for cast samples for temperatures in the range of 300–550 K were measured by using a standard dc four-point probe technique. The variations of thermal conductivity with temperature for the same alloys were determined from the WiedemannFranz and SmithPalmer equations by using the measured values of electrical resistivity. The enthalpy of fusion for the same alloys were determined by means of a differential scanning calorimeter from a heating trace during the transformation from solid to liquid. The corrosion resistance was analyzed by Tafel extrapolation and linear polarization resistance methods conducted in a 5% sodium chloride solution in contact with air maintained at room temperature. Effects of the growth rate on the electrical resistivity and corrosion resistance were also investigated.

Microcor Corrosion Monitoring Technology and its Applications

With the purpose of comprehensive understanding of the oil and gas pipeline corrosion factors and formulating correct anti-corrosion programs, working principle, technical characteristic, monitoring procedures, application examples of Microcor corrosion monitoring were described in this paper. Compared with commonly used corrosion monitoring technology such as weight loss method, linear polarization resistance method, resistance probe method, Microcor corrosion monitoring has the advantages of high sensitivity, wide application, stable performance, fast response and high resolution. Microcor corrosion monitoring corrosion is the ideal test technology of corrosion process monitoring and corrosion process control, especially for the inhibitor effect evaluation.