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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: 3 September 2019

Qingmiao Ding, Zili Li, Tao Shen and Gan Cui

This paper aims to research the corrosion behavior of the metal under the disbonded coatings interfered with AC through electrochemical method.

Abstract

Purpose

This paper aims to research the corrosion behavior of the metal under the disbonded coatings interfered with AC through electrochemical method.

Design/methodology/approach

The corrosion behavior of the metal under disbond coating interfered with alternate stray current (AC) was studied by electrochemical methods using the rectangular coating disbonded simulator. The obtained data from electrode potential test, electrochemical impedance spectroscopy (EIS) and polarization curves in simulated soil solution indicated that under the natural corrosion condition, the self-corrosion potential and the corrosion current density of the metal at different depths under disbond coating had obviously changed if there was AC interference.

Findings

The self-corrosion potential of the metal at the same depths under disbond coating shifted negatively with the rising of the AC voltage. Under the condition of cathode polarization, there was still obvious potential gradient with the extension of the deep peeling of the coating gap, and the corrosion current density of the test points was minimum, and the protection effect was best when the cathode protection potential was −1.0 V. When the metal was applied with over-protection, the corrosion rate of the metal increased as AC stray current flowing through it increased.

Originality/value

This paper used the rectangular aperture device to study the corrosion behavior of X80 steel under the disbonded coatings through electrochemical methods when the AC stray current interference voltage was 0V, 1V, 5V or 10V and the protection potential was 0V, −0.9V, −1.0V, −1.2V or −1.3V, respectively. There is great significance to the safe operation and long-term service of pipeline steel in soil environment.

Details

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

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Article
Publication date: 11 September 2009

A. Elango, V.M. Periasamy and M. Paramasivam

The purpose of this paper is to study to minimize the self‐corrosion rate of Type 57S aluminium containing (97.7 per cent Al, 2 per cent Mn and 0.03 per cent Mg) in 2 M…

Abstract

Purpose

The purpose of this paper is to study to minimize the self‐corrosion rate of Type 57S aluminium containing (97.7 per cent Al, 2 per cent Mn and 0.03 per cent Mg) in 2 M NaOH solution containing 0.2 M zinc oxide and 700 ppm of polyaniline.

Design/methodology/approach

The approach is used to measure weight loss and polarization measurements.

Findings

Results obtained show that as the amount of polyaniline is increased, the self‐corrosion rate of Alloy 57S aluminium decreases appreciably. Additionally, the open circuit potential is more in the case of 700 ppm level of polyaniline (−1.630 V) compare to 600 ppm level of polyaniline (−1.587 V). From this paper, it is also observed that the anodic polarization is greater than the cathodic polarization, thereby indicating that the overall corrosion of Alloy 57S 2 M NaOH containing 0.2 M ZnO and 700 ppm of polyaniline is under anodic control.

Originality/value

The results of the study clearly reveal that the overall corrosion of Alloy 57S aluminium in 2 M NaOH containing 0.2 M ZnO and 700 ppm of polyaniline is under anodic control. Hence, the 57S grade aluminium can be used as a potential candidate (anode) in alkaline batteries.

Details

Anti-Corrosion Methods and Materials, vol. 56 no. 5
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 29 April 2014

Khaled Alawadhi, Mylène Martinez, Abdulkareem Aloraier and Jalal Alsarraf

The aim of this investigation was to compare the performance of three typical oil field carbon dioxide corrosion inhibitors in controlling preferential weld corrosion…

Abstract

Purpose

The aim of this investigation was to compare the performance of three typical oil field carbon dioxide corrosion inhibitors in controlling preferential weld corrosion (PWC) of X65 pipeline steel in artificial seawater (3.5 weight per cent) saturated with carbon dioxide at one bar pressure.

Design/methodology/approach

A novel rotating cylinder electrode (RCE) apparatus was used to evaluate the effect of flow on the inhibition for the weld metal (WM), heat-affected zone (HAZ) and parent material. To fulfill this objective, the galvanic currents flowing between the weld regions were recorded using parallel zero-resistance ammeters, and the self-corrosion rates of the couples were obtained by linear polarization resistance measurements.

Findings

The results showed that when 30 ppm of green oil field inhibitors were present in the service environment, a current reversal took place, resulting in accelerated weld corrosion. At high shear stress, the currents increased and further reversals occurred. The inhibitors were more effective in controlling the self-corrosion rates of the parent material than of the WM and HAZ material. It was concluded that PWC was caused by unstable conditions in which the inhibitor film was selectively disrupted from the WM and HAZ, but remained effective on the parent material.

Originality/value

Electrochemical corrosion rate measurements were carried out using an RCE produced from the different regions of the weld. An advantage of using the RCE is that the hydrodynamic conditions are very well defined, and it is feasible to translate the conditions that are known to exist in a production pipeline to those used in laboratory tests.

Details

Anti-Corrosion Methods and Materials, vol. 61 no. 3
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 31 January 2020

Xiaobo Wang, Wen Zhan and Boyi Gui

The purpose of this paper is to develop a chrome-free and phosphorus-free chemical conversion coating with good corrosion resistance, a novel chemical conversion coating…

Abstract

Purpose

The purpose of this paper is to develop a chrome-free and phosphorus-free chemical conversion coating with good corrosion resistance, a novel chemical conversion coating was prepared by adding cerium nitrate hexahydrate and salicylic acid in the treatment solution containing titanium/zirconium ions on 6061 aluminum alloy.

Design/methodology/approach

Compared with the AA6061 aluminum alloy matrix, the self-corrosion potential of the conversion coating is significantly positively shifted, the self-corrosion current density is greatly reduced and its corrosion resistance is significantly improved. Morphology and composition of the conversion coatings were observed by scanning electron microscopy and energy-dispersive X-ray spectroscopy. The microdomain structure of conversion coatings at different formation stages was analyzed by electron probe microanalyzer.

Findings

An optimized preparation technique of titanium–zirconium chemical conversion coating for AA6061 aluminum alloy is obtained: H2TiF6 4 mL/L, H2ZrF6 0.4 mL/L, salicylic acid 0.35 g/L, Ce(NO3)3·6H2O 0.14 g/L, reaction temperature 30°C, reaction time 120 s and pH 4.0.

Originality/value

The coating forms on the Al(Fe)Si intermetallic compound, and Ce3+ is preferentially adsorbed on the intermetallic compound. The hydrolysis of Ce3+ causes the local pH of the solution to decrease, which promotes matrix dissolution and charge migration. As the microanode/microcathode reaction occurs, the local pH of the solution increases, and Al2O3/ZrO2/TiO2 begins to deposit on the surface of the metal substrate.

Details

Anti-Corrosion Methods and Materials, vol. 67 no. 2
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 20 March 2009

G.T. Parthiban, N. Palaniswamy and V. Sivan

The purpose of this paper is to investigate the influence of manganese addition on sacrificial anode characteristics of electrolytic magnesium.

Abstract

Purpose

The purpose of this paper is to investigate the influence of manganese addition on sacrificial anode characteristics of electrolytic magnesium.

Design/methodology/approach

Different contents of manganese were added to magnesium. Anode characteristics were evaluated and correlated to added manganese.

Findings

The performance of an anode depends strongly on the manganese content. An optimum value for the manganese to be added was identified. The impurity levels to obtain efficiencies above 50 per cent also are reported.

Originality/value

This paper highlights the properties of magnesium‐manganese binary alloys for use as sacrificial anodes in cathodic protection.

Details

Anti-Corrosion Methods and Materials, vol. 56 no. 2
Type: Research Article
ISSN: 0003-5599

Keywords

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Article
Publication date: 9 April 2021

Yanbo Zhu, Xiaohong Chen, Ping Liu, Shaoli Fu, Honglei Zhou and Jiayan Wu

This study aims to investigate the effect of changes in iron content in 70/30 copper–nickel alloy on the corrosion process.

Abstract

Purpose

This study aims to investigate the effect of changes in iron content in 70/30 copper–nickel alloy on the corrosion process.

Design/methodology/approach

70Copper–30Nickel-xFe-1Mn (x = 0.4,0.6,0.8,1.0 Wt.%) alloy were prepared by the high frequency induction melting furnace. The scanning electron microscope, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy were used to analyze the morphology and component of the corrosion product film.

Findings

The results show that the corrosion resistance of 70/30 copper–nickel alloy added with 1.0%Fe is the best, and the film is divided into inner dense Cu2O composite film and outer hydration loose layer; XRD showed that after adding 1.0% Fe, the content of Cu2(OH)3Cl in the corrosion product film was significantly reduced, while the content of Cu2O remained unchanged; XPS showed that nickel accumulates in the inner layer of corrosion product film; the stage growth mode of the film, the role of nickel in it and the enrichment mechanism of iron in the inner film were summarized and discussed.

Originality/value

The changes in the composition and structure of the corrosion product film caused by the iron content are revealed, and the mechanism of the difference in corrosion resistance is discussed.

Details

Anti-Corrosion Methods and Materials, vol. 68 no. 2
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 30 April 2020

Gang Wang, Yue Zhang, Chen Gao, GuangTao Xu and MingHao Zhao

The purpose of this paper is to investigate, the effects of residual stress and microstructure on the corrosion behaviour of carburised 18CrNiMo7-6 steel in a 3.5% NaCl…

Abstract

Purpose

The purpose of this paper is to investigate, the effects of residual stress and microstructure on the corrosion behaviour of carburised 18CrNiMo7-6 steel in a 3.5% NaCl aqueous solution.

Design/methodology/approach

The electrochemical tests were conducted using an electrochemical workstation with a three-electrode system in a 3.5% NaCl aqueous solution, the residual stress of each working face was measured by a high-speed residual stress analyser, and microstructure of different carburised layers were observed scanning electron microscopy. Finally, the effect of carbon content, microstructure and residual stress on the corrosion behaviour of the steel was discussed.

Findings

The results showed that the residual compressive stress in the carburised layer initially increased and subsequently decreased with increasing depth of the carburised layer, reaching stability in the matrix layer. The electrochemical tests before and after stress reduction showed that the electrochemical impedance and the electrochemical potential increased with the reduction of residual compressive stress.

Originality/value

The residual compressive stress in the carburised layer initially increases and subsequently decreases with increasing carburised layer depth. The electrochemical impedance and the electrochemical potential increased with the reduction of residual compressive stress. The general relationship between electrochemical potential and residual stress was established.

Details

Anti-Corrosion Methods and Materials, vol. 67 no. 4
Type: Research Article
ISSN: 0003-5599

Keywords

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Article
Publication date: 11 December 2019

Zhangyu Wu, Hongfa Yu, Haiyan Ma, Bo Da and Yongshan Tan

Coral aggregate seawater concrete (CASC) is a new type of lightweight aggregate concrete that is becoming widely used in reef engineering. To investigate the corrosion…

Abstract

Purpose

Coral aggregate seawater concrete (CASC) is a new type of lightweight aggregate concrete that is becoming widely used in reef engineering. To investigate the corrosion behavior of different kinds of rebar in CASC exposed to simulated seawater for 0-270 d, the electrochemical techniques, including linear polarization resistance (LPR) technique and the electrochemical impedance spectroscopy (EIS), were used in the present work.

Design/methodology/approach

The electrochemical techniques, including LPR technique and the EIS, were used in the present work.

Findings

Based on the time-varying law of linear polarization curves, self-corrosion potential (Ecorr), polarization resistance (Rp), corrosion current density (Icorr), corrosion rate (i), and the characteristics of EIS diagrams for different types of rebar in CASC, it can be found that the anti-corrosion property of them can be ranked as epoxy resin coated steel > 2205 duplex stainless steel (2205S) > 316 L stainless steel (316 L) > organic coated steel > ordinary steel. Additionally, the linear regression equation between Rp and charge transfer resistance (Rct) was established. Finally, the EIS corrosion standard of rebar was established from the LPR corrosion standard, which provides a direct standard for the EIS technique to determine the condition of rebar in CASC.

Originality/value

The linear regression equation between polarization resistance and charge transfer resistance was established. And the EIS corrosion standard of rebar was established from the LPR corrosion standard, which provides a direct standard for the EIS technique to determine the condition of rebar in CASC.

Details

Anti-Corrosion Methods and Materials, vol. 67 no. 1
Type: Research Article
ISSN: 0003-5599

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Article
Publication date: 5 December 2016

Ruijie Zhang, Xiaoyan Liu, Zhaopeng Wang and Fei Gao

The purpose of this study is to research the effects of interrupted aging on the corrosion behavior of Al–Cu–Mg–Ag heat-resistant alloy by means of intergranular corrosion…

Abstract

Purpose

The purpose of this study is to research the effects of interrupted aging on the corrosion behavior of Al–Cu–Mg–Ag heat-resistant alloy by means of intergranular corrosion (IGC) testing, potentiodynamic polarization combined with optical microscopy and transmission electron microscopy.

Design/methodology/approach

The results show that the IGC began on the grain boundaries and continued along the grain boundary. The corrosion resistance property of Al–Cu–Mg–Ag alloy was enhanced by interrupted aging. The precipitations of the interrupted aged sample both in the grains and on the grain boundaries were fine, and the chain-like phases on the grain boundary were distributed nearly continuously.

Findings

The corrosion resistance of Al–Cu–Mg series Al alloy with equilibrium phase (Al2Cu) is notably determined by precipitation-free zone (PFZ) as the self-corrosion potentials of (Al2Cu), PFZ and the matrix satisfied the relation EPFZ < Eθ<EMatrix.

Originality/value

The connections of the PFZ on both sides of the grain boundary decreased the corrosion resistance of Al–Cu–Mg–Ag alloy treated by the single aging.

Details

World Journal of Engineering, vol. 13 no. 6
Type: Research Article
ISSN: 1708-5284

Keywords

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