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Article
Publication date: 1 October 1999

G. Subramanian, S. Palraj and T.M. Balasubramanian

The galvanic corrosion interactions of zinc and SS.304 have been studied in a tropical marine environment over a period of 427 days, under different area ratios. The…

Abstract

The galvanic corrosion interactions of zinc and SS.304 have been studied in a tropical marine environment over a period of 427 days, under different area ratios. The galvanic interaction of zinc and SS.304 are highlighted in terms of the corrosion rate of zinc or SS.304 resulting from galvanic coupling, and the susceptibility of zinc to pitting due to galvanic corrosion. The galvanic potential and galvanic current of the system are monitored. The corrosion products at the interface of the bimetallic contacts are analysed with XRD technique and the pitting/grooving on zinc resulting from galvanic corrosion is measured using a high resolution microscope. The weathering parameters and environmental pollutants are monitored to give an insight into the possible means of favouring the galvanic interactions. The results of the study are discussed in the light of the above factors towards predicting a mechanism for the galvanic interactions of zinc and SS.304.

Details

Anti-Corrosion Methods and Materials, vol. 46 no. 5
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 6 November 2009

Abdollah Afshar, Mohsen Shirazi, Masoud Rahman and Esmaeil Fakheri

The purpose of this paper is to evaluate the galvanic corrosion of nitinol orthodontic wires with six dental alloys in artificial saliva and consider the effect of…

Abstract

Purpose

The purpose of this paper is to evaluate the galvanic corrosion of nitinol orthodontic wires with six dental alloys in artificial saliva and consider the effect of initiated localized corrosion and real surfaces of anode and cathode on galvanic current.

Design/methodology/approach

Linear polarization and cyclic polarization curves for each alloy in de‐aerated Duffo and Castillo's artificial saliva are obtained. Galvanic corrosion investigation is conducted by polarization curve intersection and mixed potential theory methods. In order to verify the initiation of localized corrosion, scanning electron microscopy is used.

Findings

Initiation of localized corrosion on the anode increases the galvanic current up to 45 times and therefore considering the effect of localized corrosion on galvanic corrosion is necessary. Placing stainless steel brackets or Aristaloy amalgam in direct contact to nitinol arch wire is not recommended.

Originality/value

In order not to underestimate the galvanic corrosion between two alloys, it is recommended to consider the effects of localized corrosion and anode/cathode surface area ratio. In this paper, an electrochemical method for estimating these factors is proposed.

Details

Anti-Corrosion Methods and Materials, vol. 56 no. 6
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 19 August 2019

Hualiang Huang and Furong Bu

The purpose of this study is to provide a theoretical basis for the study of the galvanic corrosion mechanism of copper coupled silver-coating under a thin electrolyte…

Abstract

Purpose

The purpose of this study is to provide a theoretical basis for the study of the galvanic corrosion mechanism of copper coupled silver-coating under a thin electrolyte layer in electronic systems.

Design/methodology/approach

Electrochemical measurements and surface characterizations.

Findings

The results indicate that the potential difference between copper and silver electrodes first quickly increases, and then reaches a relatively stable and large value with the extension of the immersion time. With the significant increase in the cathode/anode area ratio in electronic systems, the area ratio effect obviously accelerates the corrosion of copper due to the remarkable promotion of the cathode process. For a large cathode/anode area ratio, the galvanic current density always maintains a large value and exhibits an increasing trend with the extension of the immersion time, which is attributed that the area ratio effect reduces the protection of corrosion products. For the same area of cathode and anode, the galvanic current density always maintains a small value with the extension of the immersion time due to a low galvanic effect and protective corrosion products.

Practical implications

This work provides some information for the establishment of reliably protective measures for electronic systems in service.

Social implications

This work not only provides some information for the establishment of reliably protective measures for electronic systems in service, but also provides a theoretical basis for the selection of metal materials in microelectronic systems.

Originality/value

This work provides not only a theoretical basis for the study of the galvanic corrosion mechanism of Cu/Ag under a thin electrolyte layer, but also provides some information for the establishment of reliably protective measures for electronic systems in service.

Details

Anti-Corrosion Methods and Materials, vol. 66 no. 6
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 25 July 2019

Chi Zhang, Dajiang Zheng, Guang-Ling Song, Yang Guo, Ming Liu and Hamid Kia

This study aims to propose a simple experimental method to distinguish the galvanic corrosion, crevice corrosion and self-corrosion in metal/carbon fiber reinforced…

Abstract

Purpose

This study aims to propose a simple experimental method to distinguish the galvanic corrosion, crevice corrosion and self-corrosion in metal/carbon fiber reinforced polymer (CFRP) joints.

Design/methodology/approach

The corrosion behaviors of four different galvanic couples, whose anodes were Zn-coated DP590 steel and Al 6022, and cathodes were two kinds of CFRP, were investigated in immersion and GMW14872 cyclic conditions.

Findings

The results showed that the galvanic corrosion caused by direct contact between CFRP and metals was more serious than that caused by the jointing bolts. The corrosion damage caused by crevice corrosion was severer than that caused by galvanic corrosion. Self-corrosion was also significant, particularly under the cyclic salt spray condition.

Practical implications

Cyclic salt spray test may more reliably simulate the galvanic corrosion of a joint in industrial service environments, and real corrosion damage may be underestimated by a galvanic current measurement.

Originality/value

A deeper understanding of different corrosion mechanisms involved in CFRP/metal joints under different service conditions in industry has been given.

Details

Anti-Corrosion Methods and Materials, vol. 66 no. 4
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 13 September 2011

Reza Moshrefi, Mohammad Ghassem Mahjani, Ali Ehsani and Majid Jafarian

This paper aims to investigate the galvanic corrosion of titanium/L 316 stainless steel, by electrochemical noise (EN), electrochemical impedance spectroscopy (EIS), and…

Abstract

Purpose

This paper aims to investigate the galvanic corrosion of titanium/L 316 stainless steel, by electrochemical noise (EN), electrochemical impedance spectroscopy (EIS), and anode/cathode area ratio effect on the galvanic behavior of the couple.

Design/methodology/approach

The EN measurement was employed to examine effects of anode to cathode area ratio on the galvanic corrosion behavior between stainless steel L 316 and titanium in artificial seawater. Current noise and potential noise were monitored simultaneously using a three‐electrode configuration under open‐circuit condition. The noise resistance was evaluated as the ratio of the standard deviation of the potential to that of the current noise after removing the DC component. The time‐series noise patterns were transformed into frequency domain by fast Fourier transformation and then their power spectrum densities (PSDs) at specified frequency were determined and compared with the EIS and polarization results.

Findings

The EN, EIS and polarization results were in agreement. Galvanic corrosion density increase and galvanic potential moved slowly to negative direction with decrease in anode/cathode area ratio. The results showed that the slope of PSD of the current (i.e the “roll off”) was rising slowly where the anode/cathode area ratio was declined. The relationship between polarization resistance (Rp) and noise resistance (Rn) was investigated. Rt was determined by EIS for samples, and its value compared with Rp and Rn. The result indicates that galvanic corrosion has an inversely relation with anode/cathode area ratio that exposed to aggressive environment.

Originality/value

This paper presents the application of noise analysis to demonstrate galvanic corrosion and the effect of area ratio anode/cathode on current density and galvanic potential.

Details

Anti-Corrosion Methods and Materials, vol. 58 no. 5
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 6 March 2017

Yunze Xu, Yi Huang, Limin He, Fei Yang and Xiaona Wang

In this study the aim was to investigate under-deposit corrosion (UDC) behavior and the action effects of amino trimethylene phosphonic acid (ATMP) in the oxygen-contained…

Abstract

Purpose

In this study the aim was to investigate under-deposit corrosion (UDC) behavior and the action effects of amino trimethylene phosphonic acid (ATMP) in the oxygen-contained solution.

Design/methodology/approach

Electrochemical methods and wire beam electrode techniques were used for the study of ATMP action effect for X65 steel under silica sand and CaCO3 particle deposit. Electronic coupon technique was used for the study of galvanic effect caused by the deposits and the action effect of ATMP.

Findings

ATMP would cause localized corrosion for the silica sand-covered steel. However, it could inhibit the localized corrosion of the steel beneath CaCO3 particle deposit. Galvanic effect test showed that the galvanic effect caused by the deposits was an important factor for the acceleration of UDC. ATMP had an obvious promotion effect for the galvanic current between bare coupon and silica sand covered coupon and different degrees of localized corrosion were observed beneath both deposits.

Originality/value

The authors believe that the paper may be of particular interest to the readers of the journal as the measurement methods for the UDC of X65 pipeline steel. The experiment they did in the laboratory found that the inhibitor ATMP has a good inhibition effect for bare steel, but it would accelerate the UDC. Different kinds of deposits would have different influences for the UDC behavior with inhibitor added.

Details

Anti-Corrosion Methods and Materials, vol. 64 no. 2
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 28 October 2014

Deng Hongda and Zeng Shunpeng

The purpose of this investigation was to research the corrosion behavior of welded joints of bimetallic composite tube (X65/316L) welded with Inconel 625 in simulated sea…

Abstract

Purpose

The purpose of this investigation was to research the corrosion behavior of welded joints of bimetallic composite tube (X65/316L) welded with Inconel 625 in simulated sea water and in simulated production water, respectively.

Design/methodology/approach

The different electrochemical corrosion and galvanic corrosion behaviors of different welded zones were identified using the dynamic potential scan method and galvanic corrosion technique.

Findings

The heat-affected zone (HAZ) of welded joints was the most critical zone for corrosion. The closer to the welding line, more severe was the corrosion that was evident in the HAZ at room temperature. In welded joints of X65 tested in simulated seawater, tremendous corrosion occurred in the HAZ, followed by the base metal, and finally the welding line. However, there were few differences in corrosion of the different zones of welded joints in 316L in simulated production water. In such joints of 316L, corrosion comparatively attacked more easily to the HAZ. In galvanic corrosion tests, tremendous galvanic corrosion was evident on welded joints on X65, but comparatively slight gavanic corrosion appeared at welded joints in 316L. With the increased temperature, galvanic corrosion of welded joints was enhanced.

Originality/value

The results can provide reference for reducing the gavalic corrosion of welded bimetallic composite tube metal in the actual operation.

Details

Anti-Corrosion Methods and Materials, vol. 61 no. 6
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 30 April 2020

Xiaohua Li, Yi Shao, Weixing Miao, Yongchang Liu, Zhiming Gao and Chenxi Liu

The purpose of this paper is to focus on the galvanic corrosion behaviors of the low-carbon ferritic stainless steel electrical resistance welding (ERW) joint in the…

Abstract

Purpose

The purpose of this paper is to focus on the galvanic corrosion behaviors of the low-carbon ferritic stainless steel electrical resistance welding (ERW) joint in the simulated seawater.

Design/methodology/approach

The electrochemical methods such as electrochemical noise, galvanic current and TOEFL polarization curve tests were used to study the galvanic corrosion behaviors of ERW joints of low-carbon ferritic stainless steel in simulated seawater. On this basis, a reliable accelerated corrosion method was developed.

Findings

The corrosion type of the base metal and joint is the typical local corrosion. The order of corrosion resistance from strong to weak is: weld zone > base metal > low-temperature heat-affected zone (HAZ) > high-temperature HAZ. The results of constant current-constant potential accelerated corrosion test show that after constant current-constant potential accelerated corrosion, the joints present a typical groove corrosion pattern. The groove initiating area is located in the HAZ, and the corrosion degree in the weld zone is relatively light, which is consistent with the electrochemical test results.

Originality/value

This paper has clarified the galvanic corrosion behaviors of low-carbon ferritic stainless steel ERW joints. Moreover, a reliable accelerated corrosion method for the low-carbon ferritic stainless steel ERW joint has been developed.

Details

Anti-Corrosion Methods and Materials, vol. 67 no. 3
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 11 October 2018

Zahra Shahriyari and Khalilollah Gheisari

In this study, corrosion behavior of X53CrMnNiN219 austenitic stainless steel (SS) and X45CrSi93 martensitic SS, as well as the galvanic corrosion produced by coupling of…

Abstract

Purpose

In this study, corrosion behavior of X53CrMnNiN219 austenitic stainless steel (SS) and X45CrSi93 martensitic SS, as well as the galvanic corrosion produced by coupling of these dissimilar alloys, are evaluated in a 3.5 Wt.% NaCl solution at temperature 25°C ± 1°C.

Design/methodology/approach

The corrosion parameters were estimated through a series of electrochemical tests, including Tafel polarization, electrochemical impedance spectroscopy (EIS), and zero-resistance ammeter (ZRA) technique.

Findings

The results of polarization measurements indicate that the value of corrosion current in the galvanic pair is slightly higher than that of both the austenitic and martensitic SS during the initial time of immersion in the chloride solution, which is an indication of compatibility of members in the couple. The galvanic current density measured by ZRA technique shows negative values throughout the test; accordingly, the martensitic SS acts as anode of the pair and corrodes preferentially. Localization index values are limited to the mixed corrosion process, showing relative susceptibility of the martensitic alloy to the uniform and localized corrosion (pitting) due to chloride ions.

Originality/value

The originality is the evaluation of galvanic corrosion susceptibility of X53CrMnNiN219 and X45CrSi93 SSs in chloride solution by the various electrochemical methods consisting of Tafel polarization, EIS, and (ZRA) technique. To our knowledge, no work has been reported on this issue for these chemical compositions under this condition up to now.

Details

Anti-Corrosion Methods and Materials, vol. 65 no. 6
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 12 September 2008

Hassan Malik, Ridzuan Bin, Hamid and Esa Haruman

The purpose of this paper is to illustrate the complex nature of galvanic corrosion and how it is affected by various key factors related to material characteristics and…

Abstract

Purpose

The purpose of this paper is to illustrate the complex nature of galvanic corrosion and how it is affected by various key factors related to material characteristics and material processing parameters. In particular, this study aims to explore the effect of pH and temperature on the integrity of a system galvanically protected through the use of zinc anodes.

Design/methodology/approach

This study involved electrochemical testing at 24, 35 and 50°C in acidic and neutral solutions. As the environmental temperature and pH change the corrosion potential, galvanic potential and galvanic current may alter. This could influence the expected life of an anode used to protect processing equipment. Accordingly, the experimental design methodology involved collection of corrosion potential, galvanic current and galvanic potential data for zinc and zinc coupled to steel. This information was then used to calculate the life of zinc anodes at different temperatures and pH.

Findings

Results indicate that changes in pH and temperature can influence the potential of zinc, the galvanic current in a steel couple and the galvanic potential of zinc joined to steel. Calculations based on the accumulation of these data have revealed that at constant pH as the temperature was decreased, the driving potential of the zinc increased. Through further analysis, it was found that as a consequence of changes in driving potential the integrity of a structure may be put at risk due to fluctuations in pH and temperature.

Practical implications

Practically the research can help predict whether the integrity of a structure protected by zinc sacrificial anodes is at risk depending upon changes in pH and temperature.

Originality/value

Previous work was related mainly to galvanic corrosion at one particular pH and temperature. In this investigation, a range of pH and temperature values was used for the application of zinc anodes. The paper will be of value to engineers involved in the design of cathodic protection systems for oil field equipment, where changes in the acidity of the environment may occur due to differing levels of CO2 and H2S entering a structure.

Details

Anti-Corrosion Methods and Materials, vol. 55 no. 5
Type: Research Article
ISSN: 0003-5599

Keywords

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