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Article
Publication date: 8 January 2020

Zhiping Zhu, Chun Shi, Yu Zhang and Zhifeng Liu

The purpose of this paper is to study the effects of Cl and direct stray current on the soil corrosion of three grounding grid materials.

Abstract

Purpose

The purpose of this paper is to study the effects of Cl and direct stray current on the soil corrosion of three grounding grid materials.

Design/methodology/approach

The electrochemical corrosion properties of three grounding grid materials, which include the Q235 steel, Q235 galvanized flat steel and copper, were measured by means of the weak polarization curve method and electrochemical impedance spectroscopy; the corrosion rate of specimens was calculated using the weight loss method; and the specimen surfaces were characterized using the scanning electron microscopy, energy-dispersive spectroscopy and X-ray diffraction analysis.

Findings

Results showed that both factors, Cl and direct stray current, can accelerate the corrosion rate of grounding grid materials. The magnitude of DC stray current density affected the mass transfer type and response frequency of the anode and cathode reaction of grounding materials, while the Cl contents of the soil only affect the mass transfer rate of the electrode material from the electrochemical impedance spectroscopy diagrams. The electric field generated by the DC stray current caused Cl directed migration. The larger the DC stray current density, the greater the diffusion process and the greater the weight loss rate of the grounding grid materials that would have a logarithmic relationship with the Cl content at the same DC stray current density. The corrosion resistance of the three materials is copper > Q235 galvanized flat steel > Q235 flat steel.

Originality/value

The paper provides information regarding the relationship among Cl, direct stray current and corrosion of three grounding grid materials by means of electrochemical impedance spectroscopy. Meanwhile the weight loss rate is the logarithmic relationship with the Cl content, which is useful for understanding the corrosion mechanism of Q235 steel, Q235 galvanized flat steel and copper under the condition of Cl and direct stray current in soil.

Details

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

Keywords

Article
Publication date: 1 June 2022

Yun Bai, Baozhuang Sun, Wenzhu Huangfu, Xianjin Sun, Zhiyong Liu, Cuiwei Du and Xiaogang Li

The purpose of this paper was to study the relationship between safe storage life and storage mode of hot-rolled sheet (Q235, X70) in humid environment, and a prediction model of…

Abstract

Purpose

The purpose of this paper was to study the relationship between safe storage life and storage mode of hot-rolled sheet (Q235, X70) in humid environment, and a prediction model of safe storage life under different storage modes was established.

Design/methodology/approach

The corrosion behavior of hot-rolled sheets under different storage conditions was studied with immersion experiment and morphology observation.

Findings

The results show that pitting occurs on the hot-rolled sheets in humid environment, and the corrosion behavior is strongly related with the storage mode. When they are stored separately, the number and depth of pits first increase and then decrease as the Cl concentration rises, while for the stack storage, pit depth increases with increasing Cl concentration. The safe storage time of separate storage is longer than that of stack storage. Based on this, a model of chloride ion concentration and storage life was established.

Originality/value

A storage safe life model of hot-rolled sheet in humid environment is proposed.

Details

Anti-Corrosion Methods and Materials, vol. 69 no. 5
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 5 May 2015

Min Zhang, Hong-Hua Ge, Xue-Juan Wang, Xin-Jing Meng, Yu-Zeng Zhao and Qiang-Qiang Liao

– The purpose of this study was to explore the differences in the corrosion behavior of carbon steel in simulated reverse osmosis (RO) product water, and in seawater.

Abstract

Purpose

The purpose of this study was to explore the differences in the corrosion behavior of carbon steel in simulated reverse osmosis (RO) product water, and in seawater.

Design/methodology/approach

The wire beam electrodes (WBE) and coupons made from Type Q235 carbon steel and were immersed in simulated reverse osmosis product water, and in seawater, for fifteen days. The corrosion potential distribution on the WBE at different times was measured. The corrosion rates of the carbon steel in different solutions were obtained using weight loss determinations. The different corrosion behavior of carbon steel in the two kinds of solution was analyzed.

Findings

The results showed that the average corrosion potential, micro-cathode potential and micro-anode potential of the WBE decreased with time in simulated RO product water. During this period, the maximum potential difference between micro-cathodes and micro-anodes on the WBE surface also decreased with time. The potential difference was more than 260mV at the beginning of the test and was still greater than 110mV after fifteen days of immersion. The positions of cathodes and anodes remained basically unchanged and corrosion took place on the localized anode during the experiments. The average corrosion potential, micro-cathode potential and micro-anode potential on the WBE surface also decreased with time in the simulated seawater. However, the maximum potential difference between micro-cathode and micro-anode on the WBE surface in the simulated seawater was much smaller than was the case in simulated RO product water. It was 37.8 mV at the beginning of the test and was no more than 12mV after two days immersion. The positions of cathode region and anode kept changing, leading to overall uniform corrosion. The actual corrosion rate on the corroded anode region in simulated RO product water was greater than was the case in simulated seawater.

Originality/value

The corrosion behavior differences of carbon steel between in RO product water and in seawater were revealed by using wire beam electrodes (WBE). From the micro point of view, it explained the reason why the actual corrosion rate of carbon steel in RO product water was greater than that in sea water. The results can be helpful to explore future corrosion control methods for carbon steel in RO product water.

Details

Anti-Corrosion Methods and Materials, vol. 62 no. 3
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 13 June 2016

Xuhong Qiang, Xu Jiang, Frans Bijlaard and Henk Kolstein

This paper aims to investigate and assess a perspective of combining high-strength-steel endplate with mild-steel beam and column in endplate connections.

Abstract

Purpose

This paper aims to investigate and assess a perspective of combining high-strength-steel endplate with mild-steel beam and column in endplate connections.

Design/methodology/approach

First, experimental tests on high strength steel endplate connections were conducted at fire temperature 550°C and at an ambient temperature for reference.

Findings

The moment-rotation characteristic, rotation capacity and failure mode of high-strength-steel endplate connections in fire and at an ambient temperature were obtained through tests and compared with those of mild-steel endplate connections. Further, the provisions of Eurocode 3 were validated with test results. Moreover, the numerical study was carried out via ABAQUS and verified against the experimental results.

Originality/value

It is found that a thinner high-strength-steel endplate can enhance the connection’s rotation capacity both at an ambient temperature and in fire (which guarantees the safety of an entire structure) and simultaneously achieve almost the same moment resistance with a mild steel endplate connection.

Details

Journal of Structural Fire Engineering, vol. 7 no. 2
Type: Research Article
ISSN: 2040-2317

Keywords

Article
Publication date: 5 February 2024

Dongsheng Wang, Xiaohan Sun, Yingchang Jiang, Xueting Chang and Xin Yonglei

Stainless-clad bimetallic steels (SCBS) are widely investigated in some extremely environmental applications areas, such as polar sailing area and tropical oil and gas platforms…

Abstract

Purpose

Stainless-clad bimetallic steels (SCBS) are widely investigated in some extremely environmental applications areas, such as polar sailing area and tropical oil and gas platforms areas, because of their excellent anticorrosion performance and relatively lower production costs. However, the properties of SCBS, including the mechanical strength, weldability and the anticorrosion behavior, have a direct relation with the manufacturing process and can affect their practical applications. This paper aims to review the application and the properties requirements of SCBS in marine environments to promote the application of this new material in more fields.

Design/methodology/approach

In this paper, the manufacturing process, welding and corrosion-resistant properties of SCBS were introduced systematically by reviewing the related literatures, and some results of the authors’ research group were also introduced briefly.

Findings

Different preparation methods, such as rolling composite, casting rolling composite, explosive composite, laser cladding and plasma arc cladding, as well as the process parameters, including the vacuum degree, rolling temperature, rolling reduction ratio, volume ratios of liquid to solid, explosive ratio and the heat treatment, influenced a lot on the properties of the SCBS through changing the interface microstructures. Otherwise, the variations in rolling temperature, pass, reduction and the grain size of clad steel also brought the dissimilarities of the mechanical properties, microhardness, bonding strength and toughness. Another two new processes, clad teeming method and interlayer explosive welding, deserve more attention because of their excellent microstructure control ability. The superior corrosion resistance of SCBS can alleviate the corrosion problem in the marine environment and prolong the service life of the equipment, but the phenomenon of galvanic corrosion should be noted as much as possible. The high dilution rate, welding process specifications and heat treatment can weaken the intergranular corrosion resistance in the weld area.

Originality/value

This paper summarizes the application of SCBS in marine environments and provides an overview and reference for the research of stainless-clad bimetallic steel.

Details

Anti-Corrosion Methods and Materials, vol. 71 no. 2
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 3 July 2007

Ding‐Rong Qu, Yu‐Gui Zheng, Xiu Jiang and Wei Ke

The objective of the present work was to study the influence of chemical compositions of five naphthenic acids (NAs) extracted from Liaohe crude oil on their corrosivity.

Abstract

Purpose

The objective of the present work was to study the influence of chemical compositions of five naphthenic acids (NAs) extracted from Liaohe crude oil on their corrosivity.

Design/methodology/approach

Fourier‐transform infrared spectrometry and electron impact mass spectrometry were used to characterize the chemical structures and compositions if five NAs. The corrosivities of the NAs were assessed by stagnant NA corrosion (NAC) tests. An attempt was made to identify any correlation between the chemical composition of the NAs and their corrosiveness.

Findings

The acidic species in all five NA samples were saturated aliphatic and naphthenic acids and the amount of aromatic and unsaturated acids was negligible. A relationship between the carboxylic acid distribution and the molecular weight was obtained. Most of the carboxylic acids in five NAs contained 0‐3 ring structures. NAs with lower molecular weight and fewer ring structures usually were more corrosive.

Originality/value

The findings have important implications for assessing the corrosivity of acidic crude oils from various resources.

Details

Anti-Corrosion Methods and Materials, vol. 54 no. 4
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 11 September 2023

Yang Liu, Jialing Wang, Huayang Cai, Yawei Shao, Zhengyi Xu, Yanqiu Wang and Junyi Wang

Epoxy zinc-rich coatings are widely used in harsh environments because of the long-lasting cathodic protection of steel surfaces. The purpose of this paper is to use flake zinc…

Abstract

Purpose

Epoxy zinc-rich coatings are widely used in harsh environments because of the long-lasting cathodic protection of steel surfaces. The purpose of this paper is to use flake zinc powder instead of the commonly used spherical zinc powder to reduce the zinc powder content.

Design/methodology/approach

In this paper, the authors have prepared an anticorrosive zinc-rich coating using a flake zinc powder instead of the conventional spherical zinc powder. The optimal dispersion of scaly zinc powder in zinc-rich coatings has been explored by looking at the surface and cross-sectional morphology and studying the cathodic protection time of the coating.

Findings

The final epoxy zinc-rich coating with 35 Wt.% flake zinc powder content was prepared using sand-milling dispersions. It has a similar cathodic protection time and salt spray resistance as the 60 Wt.% spherical zinc-rich coating, with a higher low-frequency impedance modulus value.

Originality/value

This study uses flake zinc powder instead of the traditional spherical zinc powder. This reduces the amount of zinc powder in the coating and improves the corrosion resistance of the coating.

Details

Anti-Corrosion Methods and Materials, vol. 70 no. 6
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 10 June 2022

Guodong Li, Wenhan Liu and Guangzhi Feng

Aiming at the characteristics of large stiffness, low ductility, and poor energy dissipation capacity of cross-laminated timber (CLT) shear wall, a method of opening vertical…

Abstract

Purpose

Aiming at the characteristics of large stiffness, low ductility, and poor energy dissipation capacity of cross-laminated timber (CLT) shear wall, a method of opening vertical joints and adding low-yield dampers in CLT shear wall is proposed to improve its energy dissipation capacity and ductility.

Design/methodology/approach

The finite element model of CLT shear walls with low-yield dampers and dampers assembly was established by ABAQUS. The structural shape of low-yield dampers that meet the requirements of vertical joints in CLT shear walls is studied by numerical analysis. The influence of the number and position of low-yield dampers on the energy dissipation of the shear wall system is studied.

Findings

The results show that the low-yield damper with diamond openings should be used in the CLT shear wall, and the energy dissipation effect is the best when the CLT shear wall is uniformly covered with low-yield dampers. After the uniform arrangement of four groups of low-yield steel dampers, the energy consumption of the CLT shear wall increases by 75.38%, and the ductility increases by 13.22%.

Originality/value

There are few studies on replacing connectors between shear walls with low-yield steel dampers, and rectangular soft steel dampers are prone to stress concentration and poor deformation capacity. Therefore, this paper establishes the model of perforated low-yield damper and CLT and makes numerical analysis to determine the opening form, geometric parameters of low-yield damper, and the optimal layout scheme in CLT shear wall.

Details

Multidiscipline Modeling in Materials and Structures, vol. 18 no. 3
Type: Research Article
ISSN: 1573-6105

Keywords

Article
Publication date: 3 August 2020

Yijiang Chen, Pei Zhang, Yong Zhou and Fuan Yan

The purpose of this work is to reveal the mechanism of WO42 on surface passivation for Q235 carbon steel in tungstate solution.

Abstract

Purpose

The purpose of this work is to reveal the mechanism of WO42 on surface passivation for Q235 carbon steel in tungstate solution.

Design/methodology/approach

In Na2WO4 solutions with the different concentrations of WO42, the spontaneous passivation occurred on the surface of Q235 carbon steel when the concentration of WO42 was up to 0.13 mmol/L, which was attributed to the formations of the inner deposition film and the outer adsorption film on the Q235 surface under the action of WO42.

Findings

The inner deposition film presented a two-layer microstructure: the inside layer was composed of Fe2O3 mainly, and the outside layer comprised Fe(OH)2•nH2O, Fe(OH)3•nH2O, FeWO4 and Fe2(WO4)3.

Originality/value

Both FeWO4 and Fe2(WO4)3 repaired the defects in the outside layer of the inner deposition film; however, the outer adsorption film played a more important role in the surface passivation than the inner deposition film did.

Details

Anti-Corrosion Methods and Materials, vol. 67 no. 5
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 5 January 2015

Xianlong Cao, Hongda Deng and Wei Lan

The purpose of this study was to evaluate the grey relational analysis method as a way of determining quickly the important factors affecting the atmospheric corrosion of Q235

Abstract

Purpose

The purpose of this study was to evaluate the grey relational analysis method as a way of determining quickly the important factors affecting the atmospheric corrosion of Q235 carbon steel in one year.

Design/methodology/approach

Atmospheric corrosion exposure tests on Q235 steel were carried out at seven typical test sites in China. The test period lasted one year. The corrosion rate of the Q235 test panels was determined using the weight-loss method and environmental factors were monitored and recorded by standard methods. The importance of the various environmental factors was evaluated using the grey relational analysis method.

Findings

The results obtained by the grey relational analysis method showed that the ranking order of factors affecting the corrosion of Q235 carbon steel from “slightly” to “severely” was as follows: relative humidity > dew days > SO3 > pH value of rain > rain precipitation > temperature > rainy days > Cl− > H2S > NO2. Furthermore, the initial atmospheric corrosion of Q235 carbon steel was recognized as being the corrosion of the smooth surface by water medium, or acidic aqueous solution.

Originality/value

Materials corrosion can be defined as a grey system because corrosion has a clear outcome and complex but uncertain characteristics. The grey relational analysis method, a part of grey system theory, is an effective and quick data processing method that can be used to sort out the degree of correlation of environmental factors affecting atmospheric corrosion in terms of it being a grey system with a lot uncertain information.

Details

Anti-Corrosion Methods and Materials, vol. 62 no. 1
Type: Research Article
ISSN: 0003-5599

Keywords

1 – 10 of 131