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Article
Publication date: 6 February 2024

Shuangjiu Deng, Chang Li, Xing Han, Menghui Yu and Han Sun

The restoration and strengthening of QT600 is an industry bottleneck challenge. The Co-12 cladding layer has great wear and corrosion resistance. The purpose of this paper is to…

Abstract

Purpose

The restoration and strengthening of QT600 is an industry bottleneck challenge. The Co-12 cladding layer has great wear and corrosion resistance. The purpose of this paper is to quantitatively reveal the transient evolution law of the corrosion process of Co-12 cladding layer on QT600 surface.

Design/methodology/approach

In this paper, a three-dimensional numerical model of the corrosion process of Co-12 cladding layer by QT600 laser cladding is established. The interaction between pitting pits and corrosion medium is considered to reveal the transient evolution of ion concentration, electrode potential, pH and corrosion rate at different locations.

Findings

The calculation shows that the ion concentration in pitting pit changes Cl>Co2+>Na+, pH value decreases from top to bottom and corrosion rate at bottom is greater than that at top. The electrochemical corrosion test of Co-12 cladding layer was carried out. It is shown that the current density of QT600 increases by an order of magnitude compared to the Co-12 cladding layer, and the corrosion rate is 4.862 times higher than that of the cladding layer.

Originality/value

The results show that Co-12 cladding layer has great corrosion resistance, which provides an effective way for QT600 protection.

Details

Anti-Corrosion Methods and Materials, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 11 December 2023

B. Zhang, X.X. Wei and X.L. Ma

In recent years, using aberration-corrected transmission electron microscopy, the authors have achieved precisely detecting the structural evolution of passive film as well as its…

Abstract

Purpose

In recent years, using aberration-corrected transmission electron microscopy, the authors have achieved precisely detecting the structural evolution of passive film as well as its interface zone at atomic scale. The purpose of this paper aims to make a brief review to show the authors’ new understanding and perspective on the issue of critical factors determining stability of passive film of Fe-Cr alloy.

Design/methodology/approach

The introduction of single crystal enabled the authors to obtain a distinct metal/passive film interface and better characterize the structure of the interface region. The authors use aberration-corrected TEM to conduct cross-sectional observation and directly capture the details across the entire film at a high spatial and energy resolution.

Findings

Apart from the passive film itself, the interface zone, including metal/film (Me/F) interface and the adjacent metal side, is also the site which is attacked. Accordingly, the nature of the interface zone, such as microstructure, composition and atomic configuration, is one of the critical factors determining the stability of passive film.

Originality/value

Deciphering the critical factors determining the stability of passive film is of great significance and has been a fundamental issue in corrosion science. Great attention has been paid to the nature of the passive film itself. In contrast, the possible role of the interface between the passive film and the metal is rarely taken into account. Based on the advanced analytical tool with high spatial resolution, the authors have specified the significant role of interface structures on the macro-scale stability of passive film.

Details

Anti-Corrosion Methods and Materials, vol. 71 no. 1
Type: Research Article
ISSN: 0003-5599

Keywords

Book part
Publication date: 8 April 2024

Jana Janoušková and Šárka Sobotovičová

It is important to consider economic and political factors when designing the tax mix and setting the level of corporate taxation. Increasing corporate taxation can be seen as an…

Abstract

It is important to consider economic and political factors when designing the tax mix and setting the level of corporate taxation. Increasing corporate taxation can be seen as an inefficient way to raise revenue for the state, as it can have a negative impact on investment and the competitiveness of firms. However, lowering corporate taxation can encourage investment and job creation, but it can also be perceived as supporting large corporations. The aim of this chapter is to evaluate corporate taxation, its position in the tax mix and its potential impact on economic growth. The revenues of corporate income tax (CIT) have an increasing tendency even though the tax rate was reduced from 41% to 19%. Revenues are influenced by both legislative changes and economic cycles. The level of taxation is also influenced by deductions, which include asset depreciations, research and development expenses, or loss deductions. The Pearson Correlation Coefficient was used to examine the correlation between the selected factors. A moderately strong positive correlation was found between GDP growth and CIT as a percentage of total taxes, as well as between GDP growth and CIT as a percentage of GDP.

Details

Modeling Economic Growth in Contemporary Czechia
Type: Book
ISBN: 978-1-83753-841-6

Keywords

Article
Publication date: 14 August 2023

Yuchen Xi, Qinying Wang, Yafei Wu, Xingshou Zhang, Lijin Dong, ShuLin Bai and Yi Yang

The purpose of this study is to investigate the crevice corrosion behavior and mechanism of laser additive manufacturing (LAM) nickel-based alloy under wedge-shaped crevice.

Abstract

Purpose

The purpose of this study is to investigate the crevice corrosion behavior and mechanism of laser additive manufacturing (LAM) nickel-based alloy under wedge-shaped crevice.

Design/methodology/approach

First, the opening size of the wedge-shaped crevice was designed to 0.1, 0.3 and 0.5 mm by controlling the thickness of silicon rubber and the double-side adhesive tape. Then, one side of the glass sheet was stuck on the silicon strip and keep the electrodes of Rows 1 and 2 outside the crevice as a reference, and the opposite side was stuck to the wire beam electrode by silica gel.

Findings

The current density with a maximum value of 5.7 × 10−6 A/cm2 was observed at the crevice opening of 0.5 mm, while the lowest value of 9.2 × 10−7 A/cm2 was found at the crevice opening of 0.1 mm. In addition, the corrosion resistance at the inside of the crevice is higher than that at the outside and the middle of the crevice. It means that the internal width of the wedge-shaped crevice tends toward 0, which hinders the migration of ions in the corrosive medium. The generation of corrosive products further reduce the crevice size to cause the inhibition of corrosion at the inside of the crevice as well.

Originality/value

The multilayer and multipath LAM component is prepared to show the complex microstructure, which made the corrosion behavior and mechanism at wedge-shaped crevice nondeterminacy.

Details

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

Keywords

Article
Publication date: 12 December 2023

Ziru Zhou, Songlin Zheng, Jiahuan Chen, Ting Zhang, Zhen He and Yuxin Wang

The high specific strength makes magnesium alloys have a wide range of applications in aerospace, military, automotive, marine and construction industries. However, its poor…

Abstract

Purpose

The high specific strength makes magnesium alloys have a wide range of applications in aerospace, military, automotive, marine and construction industries. However, its poor corrosion resistance and weldability have limited its development and application. Friction stir welding (FSW) can effectively avoid the defects of fusion welding. However, the microstructure, mechanical properties and corrosion behavior of FSW joints in magnesium alloys vary among different regions. The purpose of this paper is to review the corrosion of magnesium alloy FSW joints, and to summarize the protection technology of welded joints.

Design/methodology/approach

The corrosion of magnesium alloy FSW joints includes electrochemical corrosion and stress corrosion. This paper summarizes corrosion protection techniques for magnesium alloys FSW joints, focusing on composition, microstructure changes and surface treatment methods.

Findings

Currently, this research is mainly focused on enhancing the corrosion resistance of magnesium alloy FSW joints by changing compositions, structural modifications and surface coating technologies. Refinement of the grains can be achieved by adjusting welding process parameters, which in turn minimizes the effects of the second phase on the alloy’s corrosion resistance.

Originality/value

This paper presents a comprehensive review on the corrosion and protection of magnesium alloys FSW joints, covering the latest research advancements and practical applications. It aims to equip researchers with a better insight into the field and inspire new studies on this topic.

Details

Anti-Corrosion Methods and Materials, vol. 71 no. 1
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 29 March 2024

Han Zhao, Qingmiao Ding, Yaozhi Li, Yanyu Cui and Junjie Luo

This paper aims to study the influence of microparticles on the surface cavitation behavior of 2Cr3WMoV steel; microparticle suspensions of different concentration, particle size…

Abstract

Purpose

This paper aims to study the influence of microparticles on the surface cavitation behavior of 2Cr3WMoV steel; microparticle suspensions of different concentration, particle size, material and shape were prepared based on ultrasonic vibration cavitation experimental device.

Design/methodology/approach

2Cr3WMoV steel was taken as the research object for ultrasonic cavitation experiment. The morphology, quantity and distribution of cavitation pits were observed and analyzed by metallographic microscope and scanning electron microscope.

Findings

The study findings showed that the surface cavitation process produced pinhole cavitation pits on the surface of 2Cr3WMoV steel. High temperature in the process led to oxidation and carbon precipitation on the material surface, resulting in the “rainbow ring” cavitation morphology. Both the concentration and size of microparticles affected the number of pits on the material surface. When the concentration of microparticles was 1 g/L, the number of pits reached the maximum, and when the size of microparticles was 20 µm, the number of pits reached the minimum. The microparticles of Fe3O4, Al2O3, SiC and SiO2 all increased the number of pits on the surface of 2Cr3WMoV steel. In addition, the distribution of pits of spherical microparticles was more concentrated than that of irregularly shaped microparticles in turbidity.

Originality/value

Most of the current studies have not systematically focused on the effect of each factor of microparticles on the cavitation behavior when they act separately, and the results of the studies are more scattered and varied. At the same time, it has not been found to carry out the study of microparticle cavitation with 2Cr3WMoV steel as the research material, and there is a lack of relevant cavitation morphology and experimental data.

Details

Anti-Corrosion Methods and Materials, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 10 November 2023

Wensheng Li, Yiding Zhang, Yanwei Xu, Guangming Jiao, Dunwen Zuo, Wenting Lu, Quanshi Cheng, Jiaqi Yu and Yajun Chen

This study aims to investigate the effect of post-treatment on anti-corrosion performance of Al coating on the surface of Ti-6Al-4V (TC4) fastener.

Abstract

Purpose

This study aims to investigate the effect of post-treatment on anti-corrosion performance of Al coating on the surface of Ti-6Al-4V (TC4) fastener.

Design/methodology/approach

The Al coatings with different layer structures were prepared on TC4 by middle-frequency and direct-current combined magnetron sputtering. The cross-sectional morphology and surface roughness of coatings were characterized by scanning electron microscope and atomic force microscope. The corrosion resistance was evaluated by electrochemical method. The monolayer coating was post-treated by Alodine chemical conversion, Ar+ bombardment and a combination of two methods above.

Findings

The results show that the interfaces in bilayer and trilayer coatings reduce the defects. Ar+ bombardment reduces the corrosion current density, and Alodine chemical conversion leads to a higher pitting corrosion potential. The combined post-treatment has the highest polarization resistance.

Originality/value

The corrosion resistance of the Al coating is enhanced as the layer quantity increases. The combination of two post-treatments, Ar+ bombardment and Alodine chemical conversion, could achieve an overall improvement in corrosion resistance of Al coating.

Details

Anti-Corrosion Methods and Materials, vol. 71 no. 1
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 13 December 2023

Zhenyu Ma, Yupeng Zhang, Xuguang An, Jing Zhang, Qingquan Kong, Hui Wang, Weitang Yao and Qingyuan Wang

The purpose of this study is to investigate the effect of nano ZrC particles on the mechanical and electrochemical corrosion properties of FeCrAl alloys, providing a beneficial…

Abstract

Purpose

The purpose of this study is to investigate the effect of nano ZrC particles on the mechanical and electrochemical corrosion properties of FeCrAl alloys, providing a beneficial reference basis for the development of high-performance carbide reinforced FeCrAl alloys with good mechanical and corrosion properties in the future.

Design/methodology/approach

Nano ZrC reinforced FeCrAl alloys were prepared by mechanical alloying and spark plasma sintering. Phases composition, tensile fractography, corrosion morphology and chemical composition of nano ZrC reinforced FeCrAl alloys were analyzed by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy, respectively. Microhardness and tensile properties of nano ZrC reinforced FeCrAl alloys were investigated by mechanical testing machine and Vickers hardness tester. Electrochemical corrosion properties of nano ZrC reinforced FeCrAl alloys were investigated by electrochemical workstation in 3.5 wt.% NaCl solution.

Findings

The results showed that addition of nano ZrC can effectively improve the mechanical and corrosion properties. However, excessive nano ZrC could decrease the mechanical properties and reduce the corrosion resistance. In all the FeCrAl alloys, FeCrAl–0.6 wt.% ZrC alloy exhibits the optimum mechanical properties with an ultimate tensile strength, elongation and hardness of 990.7 MPa, 24.1% and 335.8 HV1, respectively, and FeCrAl–0.2 wt.% ZrC alloy has a lower corrosion potential (−0.179 V) and corrosion current density (2.099 µA/cm2) and larger pitting potential (0.497 V) than other FeCrAl–ZrC alloys, showing a better corrosion resistance.

Originality/value

Adding proper nano ZrC particles can effectively improve the mechanical and corrosion properties, while the excessive nano ZrC is harmful to the mechanical and corrosion properties of FeCrAl alloys, which provides an instruction to develop high-performance FeCrAl cladding materials.

Details

Anti-Corrosion Methods and Materials, vol. 71 no. 1
Type: Research Article
ISSN: 0003-5599

Keywords

Article
Publication date: 31 July 2023

Badegül Tunçay, Harun Çuğ, Tansel Tunçay, Dursun Özyürek and Katarzyna Cesarz-Andraczke

This study aims to investigate NiTi alloys’ characterization and corrosion behaviour produced by two different powder metallurgy (PM) methods.

Abstract

Purpose

This study aims to investigate NiTi alloys’ characterization and corrosion behaviour produced by two different powder metallurgy (PM) methods.

Design/methodology/approach

It was pre-formed under a protective atmosphere at 900 °C under a force of 45 MPa and sintered for 1 h under 10–6 Mbar in an atmosphere-controlled heat treatment furnace at 1,100 °C. The relationship between microstructural properties, SEM, XRD, density, microhardness and corrosion behaviour of pre-alloyed NiTi alloys produced by two different methods with the production method was investigated.

Findings

As a result of the studies, TiO, NiTi, NiTi2 and Ni3Ti intermetallics were determined in XRD examinations. The best surface roughness was observed in the mechanically milled (MM’ed) pre-alloyed NiTi alloy compared to the pre-alloyed NiTi alloy mixed with turbula. The corrosion tests performed in 3.5% NaCl solution determined that the MM’ed pre-alloyed NiTi alloy had better corrosion resistance than the pre-alloyed NiTi alloy mixed with turbula. Pitting corrosion was visualized in the SEM images taken from the corrosion surfaces.

Originality/value

Two different PM methods produced pre-alloyed NiTi powders, and the effects of these methods on the mechanical and corrosion resistance of NiTi alloys were systematically investigated for the first time.

Details

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

Keywords

Article
Publication date: 27 October 2023

Junyu Shi, Shengli Ling, Yinjie Kuang, Yonggang Tong, Yongle Hu and Dunying Deng

The purpose of this paper is to reveal the effect of microstructure on the corrosion behavior of CoCrNi alloy in 3.5 Wt.% NaCl solution.

Abstract

Purpose

The purpose of this paper is to reveal the effect of microstructure on the corrosion behavior of CoCrNi alloy in 3.5 Wt.% NaCl solution.

Design/methodology/approach

The as-cast CoCrNi alloy was prepared by arc melting, and the cold-rolled and annealed alloys were prepared by processing the as-cast alloy.

Findings

The experimental results showed that a protective passivation film was formed on the surfaces of these CoCrNi MEA, and the stability and compactness of alloys increased in the sequence of cold-rolled, as-cast and annealed CoCrNi alloys. The annealed CoCrNi alloys had the best pitting resistance.

Originality/value

This study proposes the effect of the microstructure of CoCrNi alloy on corrosion resistance.

Details

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

Keywords

1 – 10 of 164