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Article
Publication date: 9 August 2019

Li-Xiang Wang, Da-Hai Xia, Shi-Zhe Song, Yashar Behnamian and Likun Xu

This paper aims to quantify atmospheric corrosion by image analyses. The corrosion extent, form and distribution of corrosion product on Q235B and T91 steels exposed to a…

Abstract

Purpose

This paper aims to quantify atmospheric corrosion by image analyses. The corrosion extent, form and distribution of corrosion product on Q235B and T91 steels exposed to a Zhoushan marine atmosphere over one year are characterized by image analysis.

Design/methodology/approach

Image analysis of corrosion images were achieved using the gray value, wavelet analysis and fuzzy Kolmogorov–Sinai (K–S) entropy.

Findings

As corrosion becomes extensive, the gray value of corrosion images decreases, and the energy value of nine subimages after wavelength decomposition decreases. Fuzzy K–S entropy increases as localized corrosion propagates but decreases as uniform corrosion spreads.

Originality/value

The methods proposed in this work open a new way for fast corrosion evaluation of metallic materials exposed to atmospheric conditions.

Details

Anti-Corrosion Methods and Materials, vol. 66 no. 5
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 31 January 2020

BaoJun Dong, Wei Liu, Fei Wu, JiaQi Zhu, Banthukul Wongpat, Yonggang Zhao, Yueming Fan and TianYi Zhang

The salinity of the oilfield produced water has a significant effect on steel corrosion. The purpose of this paper is to study the influence of salinity on corrosion

Abstract

Purpose

The salinity of the oilfield produced water has a significant effect on steel corrosion. The purpose of this paper is to study the influence of salinity on corrosion behavior of X60 steel and it also provides basic for material selection of gas wells with high salinity.

Design/methodology/approach

The weight loss experiment was carried out on steel with high temperature and high pressure autoclave. The surface morphology and composition of corrosion scales were studied by means of scanning electron microscopy, energy dispersive spectroscopy and X-ray diffractometry.

Findings

The results show that as salinity increases, the corrosion rate of X60 steel will gradually experience a rapid decline stage and then a slow decline stage. X60 steel is mainly exhibiting uniform corrosion in the first rapid decline stage and pitting corrosion in the second slow decline stage. The increase in salinity reduces gas solubility, which, in turn, changes the morphology and density of the corrosion scales of X60 steel. At low salinity, loose iron oxides generated on the surface of the steel, which poorly protects the substrate. At high salinity, surface of the steel gradually forms protective films. Chloride ions in the saline solution mainly affect the structure of the corrosion scales and initiate pitting corrosion. The increased chloride ions lead to more pitting pits on the surface of steel. The recrystallization of FeCO3 in pitting pits causes the corrosion scales to bulge.

Originality/value

The investigation determined the critical concentration of pitting corrosion and uniform corrosion of X60 steel, and the new corrosion mechanism model was presented.

Details

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

Keywords

Article
Publication date: 31 January 2020

Hailing Li, Hongxia Wan, Shengrong Wang, Cuiwei Du and Dawei Zhang

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…

Abstract

Purpose

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.

Design/methodology/approach

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.

Findings

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.

Originality/value

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.

Details

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

Keywords

Article
Publication date: 17 April 2020

Mohammed T. Hayajneh, Mohammed Ali Almomani and Shrouq M. Alelaumi

The purpose of this paper is to investigate the effects of incorporating SiC nanoparticles into ZA-27 alloy on the corrosion behavior of the produced nanocomposites.

Abstract

Purpose

The purpose of this paper is to investigate the effects of incorporating SiC nanoparticles into ZA-27 alloy on the corrosion behavior of the produced nanocomposites.

Design/methodology/approach

The nanocomposites were fabricated by a double-step stir casting technique. The corrosion behavior of the produced ZA-27 nanocomposites was investigated using potentiodynamic polarization test in a 3.5% NaCl medium. The surfaces of the fabricated metal matrix nanocomposites (MMNCs) before and after corrosion tests were imaged and analyzed using an optical microscope and scanning electron microscope (SEM) to examine the microstructure of the produced MMNCs and morphology of its surface before and after corrosion.

Findings

The corrosion test results reveal that the fabricated nanocomposites have an improved uniform corrosion resistance when compared with the corresponding monolithic matrix alloy. On the other hand, the base monolithic alloy is less susceptible to the pitting phenomenon than the nanocomposites. The electrochemical results are consistent with the pits morphology of the corroded MMNCs.

Originality/value

This study highlights the use of SiC nano-particulates for controlling of ZA alloy corrosion behavior and enhancing its anti-corrosion characteristics which will open a new route for industrial applications. The corrosion behavior of ZA-27 alloy-based composite reinforced with different weight fractions of nano-SiC particles have an improved uniform corrosion behavior as compared with the corresponding matrix alloy.

Details

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

Keywords

Article
Publication date: 6 June 2016

X.Q. Liu, Z.L. Liu, J.D. Hu, Z.G. Hou, Q.C. Tian and H.Z. Wang

The purpose of this study is to explore the corrosion behaviors of tube pile steel with the addition of 0.2 per cent Cu and 0.2 per cent Cu-0.2 per cent Cr in…

Abstract

Purpose

The purpose of this study is to explore the corrosion behaviors of tube pile steel with the addition of 0.2 per cent Cu and 0.2 per cent Cu-0.2 per cent Cr in half-immersion environment.

Design/methodology/approach

The electrochemical corrosion behaviors of tube pile steel with different alloy-elements addition were identified using the polarization curve method and electrochemical impedance spectroscopy technique. Corrosion product and its morphology were analyzed by X-ray diffraction, optical microscope and scanning electron microscopy.

Findings

Results indicate that the most serious corrosion occurred in the liquid-air interface zone due to the higher oxygen and water concentration. With the addition of Cu and Cu-Cr, pits were getting smaller and denser, transforming the corrosion type from pitting corrosion to uniform corrosion gradually. Rust layer containing Cu/Cr tended to compact and inhibited the anodic process, while the enrichment of Cu/Cr in rust layer decelerated the dissolution of substrate, thus the expanding of pits was suppressed.

Originality/value

This paper studied the corrosion behaviors of liquid-air interface zone of tube pile steel and verified the transformation of corrosion type with adding Cu, Cu/Cr elements.

Details

Anti-Corrosion Methods and Materials, vol. 63 no. 4
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 4 October 2019

Yu Fu, Jie Kou and Cuiwei Du

Pipelines are seriously corroded due to the close distance between pipelines and high voltage transmission lines. The purpose of this paper is to study the influence of…

Abstract

Purpose

Pipelines are seriously corroded due to the close distance between pipelines and high voltage transmission lines. The purpose of this paper is to study the influence of alternating current (AC) on corrosion behavior of X80 pipeline steel in coastal soil solution.

Design/methodology/approach

The corrosion behavior of X80 steel under different AC densities in coastal soil solution was investigated by electrochemical measurements and image processing technology. Furthermore, a quantitative description model of AC corrosion through fractal dimension of corrosion image was established.

Findings

The results show that under low AC density the X80 steel is mainly uniform corrosion, and once AC density reaches 150 A/m2, the corrosion morphology gradually turns to pitting corrosion with irregular circle. For another aspect, the fractal dimension of corrosion images shows that the two/three-dimensional fractal dimension increase with the increase of AC density, presenting a linear and an exponential relationship respectively. In addition, the variation of the three-dimensional fractal dimension is the same as that of average corrosion rate. The threshold of the increasing trend of fractal dimension as well as corrosion type is 150 A/m2.

Originality/value

The investigation provides a quantitative method to describe AC corrosion morphology through fractal dimension. Furthermore, the method is of benefit to process corrosion images automatically.

Details

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

Keywords

Article
Publication date: 14 October 2022

Fridtjof Holst Øyasæter, Ashish Aeran and Sudath C. Siriwardane

Several experimental and numerical studies were performed in the past to estimate buckling capacity of corroded tubular members. However, the effect of initial…

Abstract

Purpose

Several experimental and numerical studies were performed in the past to estimate buckling capacity of corroded tubular members. However, the effect of initial imperfections has not been properly considered in most of these earlier proposed formulas. Therefore, the main objective of this paper is to propose an accurate analytical formula to determine the buckling capacity of patched corroded tubular members.

Design/methodology/approach

Tubular members with initial geometrical imperfections can be regarded as beam-columns because of the combination of axial load and bending moment. The proposed formula is derived for a rectangular corrosion patch. The proposed formula is verified with results from finite element analysis of corroded tubular members and experimental results. The formula is also applied to an existing offshore jacket structure to highlight its significance and applicability. It is found that the buckling capacity of jacket members in splash zone reduces significantly with ageing. This reduction is around 29 and 14% for the selected brace and leg member respectively, during the design life. Finally, it is concluded that corrosion reduces the buckling capacity significantly and the proposed formula can be easily applied by practicing engineers to give an accurate and slightly conservative estimate the remaining buckling capacity.

Findings

The main finding is the new formula which accurately and conservatively estimate the buckling capacity of corroded tubular members. The proposed formula considers the secondary effect of both initial geometrical imperfections and shifting of centroid because of corrosion.

Originality/value

The proposed new formula is unique and original in that it considers both secondary effects from geometrical imperfections, reduction of cross-section from corrosion wastage and shifting of centroid because of corrosion. Finally, it is concluded that corrosion reduces the buckling capacity significantly and the proposed formula can be easily applied by practicing engineers to conservatively estimate the remaining buckling capacity and verify if further, more advanced estimations are needed.

Details

International Journal of Structural Integrity, vol. 13 no. 6
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 1 January 2016

Xianghong Lv, Guoxian Zhao, Fuxiang Zhang, Xiang Tong Yang, Dan Ba, Junfeng Xie and Yan Xue

The purpose of this investigation was to study the function mechanisms of a corrosion inhibitor package used for martensitic stainless steel tubulars in acid solution at…

Abstract

Purpose

The purpose of this investigation was to study the function mechanisms of a corrosion inhibitor package used for martensitic stainless steel tubulars in acid solution at high temperatures.

Design/methodology/approach

The inhibition performance was evaluated by means of an acid corrosion test at high temperature and high pressure, and the functional mechanism of the inhibitor package at different temperatures was investigated using polarization curve and electrochemical impedance spectroscopy measurements.

Findings

The results showed that the corrosion inhibitor package chosen for high-temperature and high-pressure gas well applications was very suitable for use with 13Cr super martensitic stainless steel. At lower temperatures, the function mechanism of the corrosion inhibitor package was characterized as a type of negative catalytic effect. As the temperature was increased, the effect of the intensifier in the package became more significant and the function mechanism changed to be the geometric covering effect type.

Originality/value

This study has the important practical value for guiding the oil field to conduct reasonable screening and using the acidizing corrosion inhibitor for martensite stainless steel tubulars.

Details

Anti-Corrosion Methods and Materials, vol. 63 no. 5
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 6 June 2016

Lihua Gong, Qing Xing and Huihuang Wang

The purpose of this paper is to investigate the effect of welding procedure on the corrosion behaviors of weathering steel 09CuPCrNi in marine atmospheric environment. The…

Abstract

Purpose

The purpose of this paper is to investigate the effect of welding procedure on the corrosion behaviors of weathering steel 09CuPCrNi in marine atmospheric environment. The corrosion processes of weathering steel 09CuPCrNi and its welded joints in marine atmospheric environment were simulated by a salt spray dry-wet test.

Design/methodology/approach

The corrosion behaviors of the base metal and the welded joints at corrosion times of 2, 4, 8, 12, 24 weeks were investigated by weight loss test, electrochemical techniques, scanning electron microscope (SEM) and electron probe micro-analyzer (EPMA). The corrosion rates, as well as the morphologies and electrochemical characteristics of corrosion products, the distribution of major alloying elements in rust layer were obtained. The influence of welding on the atmospheric corrosion of 09CuPCrNi was studied.

Findings

The results indicate that the corrosion rate of the 09CuPCrNi welded joints decreases gradually with the corrosion time, and the major alloying elements are enriched in the inner rust layer, which are similar to that of the base metal. In the early stage during the corrosion process, the welded joints with inhomogeneous structure show the poorer corrosion resistance than that of the base metal. However, it looks the opposite way around in the late corrosion stage, when the uniform corrosion products with even thickness of the base metal tend to detach from the substrate easier and earlier and resulting in cracks, which increase the corrosion rate comparatively with that of the welded joints.

Originality/value

09CuPCrNi low alloy steel is a kind of typical weathering steel developed in China which is similar to Corten A developed by USA. Nowadays, 09CuPCrNi low alloy steel is widely adopted in many fields which require welding processes. In the past years, the research of weathering steel welded joints was mainly concentrated on the strength, toughness and weldability. Less work has been done to investigate the difference of corrosion evolution and characteristics between the base metal and its welded joints. Thus, the main objective of the present work was to analyze the influence of welding on the atmospheric corrosion.

Details

Anti-Corrosion Methods and Materials, vol. 63 no. 4
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 1 October 1972

Pitting Pitting is possibly the most expensive form of corrosion, in that one small hole can result in the failure or destruction of a process or plant. By its very nature…

Abstract

Pitting Pitting is possibly the most expensive form of corrosion, in that one small hole can result in the failure or destruction of a process or plant. By its very nature it is a localised form of attack, the diameter of the resultant pit being approximately the same as its depth. Some materials are very prone to pitting—the pits are so close that the surface resembles a roughened specimen. The most important factor, that of pit depth, is sometimes referred to in terms of ‘pitting factor’. This relates the ratio of deepest pit to average metal penetration, the latter being derived from the weight loss of the specimen. Uniform corrosion has a pitting factor of unity.

Details

Anti-Corrosion Methods and Materials, vol. 19 no. 10
Type: Research Article
ISSN: 0003-5599

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