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1 – 10 of 370D. de la Fuente, B. Chico and M. Morcillo
The presence of soluble salts, especially chlorides and sulphates, at the metal/paint interface usually causes premature deterioration of the paint system. In practice, soluble…
Abstract
The presence of soluble salts, especially chlorides and sulphates, at the metal/paint interface usually causes premature deterioration of the paint system. In practice, soluble salts are found heterogeneously distributed in the steel corrosion products layer and are frequently located at the base steel/rust layer interface. However, in most of the research studies carried out with the aim of establishing critical concentration levels for different paint systems, panels have been prepared by dosing the saline contaminant in an uniform way across flat and unrusted steel surfaces. In order to resolve this problem, an attempt has been made to reproduce the atmospheric corrosion process of steel in environments contaminated with SO2 and Cl−, using a salt fog cabinet for the case of chlorides, and a Kesternich type cabinet for sulphates.
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The term “library management” covers many different aspects of the way that a library is operated and conjures up different concepts in the minds of different people, depending on…
Abstract
The term “library management” covers many different aspects of the way that a library is operated and conjures up different concepts in the minds of different people, depending on their own interests, agendas and requirements. Research into the subject is even more difficult to define because the application of research in one field can be vital to the development of another. Some researchers would not consider their research central to library matters at all, whereas the practising librarian might well see it as casting new light on a difficult area of understanding or development.
The complexity of atmospheric corrosion, further compounded by the effects of climate change, makes existing models inappropriate for corrosion prediction. The commonly used…
Abstract
The complexity of atmospheric corrosion, further compounded by the effects of climate change, makes existing models inappropriate for corrosion prediction. The commonly used kinetic model and dose-response functions are restricted in their capacity to represent the non-linear behaviour of corrosion phenomena. The application of artificial intelligence (AI)-driven machine learning algorithms to corrosion data can better represent the corrosion mechanism by considering the dynamic behaviour due to changing climatic conditions. Effective use of materials, coating systems and maintenance strategies can then be made with such a corrosivity model. Accurate corrosion prediction will help to improve climate change resilience of the social, economic and energy infrastructure in line with the UN Sustainable Development Goals (SDGs) 7 (Affordable and Clean Energy), 9 (Industry, Innovation and Infrastructure) and 13 (Climate Action). This chapter discusses atmospheric corrosion prediction in relation to the SDGs and the influence of AI in overcoming the challenges.
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Zhuolin Li, Dongmei Fu and Zibo Pei
This paper aims to discover the mathematical model for Q235 carbon steel corrosion date acquired in the initial stage of atmospheric corrosion using electrical resistance probe.
Abstract
Purpose
This paper aims to discover the mathematical model for Q235 carbon steel corrosion date acquired in the initial stage of atmospheric corrosion using electrical resistance probe.
Design/methodology/approach
In this paper, mathematical approaches are used to construct a classification model for atmospheric environmental elements and material corrosion rates.
Findings
Results of the experiment show that the corrosion data can be converted into corrosion depth for calculating corrosion rate to obtain corrosion kinetics model and conform corrosion acceleration phase. Combined with corresponding atmospheric environmental elements, a real time grade subdivision model for corrosion rate can be constructed.
Originality/value
These mathematical models constructed by real time corrosion data can be well used to research the characteristics about initial atmospheric corrosion of Q235 carbon steel.
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Fahimeh Ansari, Reza Naderi and Fahimeh Rafiaei
This paper aims to access the protective function of hybrid sol-gel coatings deposited on 304L stainless steel substrate in silane solutions containing a mixture of…
Abstract
Propose
This paper aims to access the protective function of hybrid sol-gel coatings deposited on 304L stainless steel substrate in silane solutions containing a mixture of tetraethoxysilane, methyltriethoxysilane and glycidyloxypropyltrimethoxysilane with different pH values during various immersion periods.
Design/methodology/approach
The 304L stainless steels coated through 10 and 30 s of immersion in the silane solutions with pH values of 2.1 and 2.8 were exposed to NaCl solution. The corrosion resistance of the coated substrates was studied through taking advantage of electrochemical noise method as well as atomic force microscopy (AFM), water contact angle and field emission-type scanning electron microscopy (FESEM) surface analysis.
Findings
The electrochemical current noise, PSD (I) plot, noise resistance and characteristic charge as parameters extracted from electrochemical noise method indicated the superiority of eco-friendly silane coating deposited on the substrate surface during 10 s exposure to the solution, due to the film uniformity and homogeneity as confirmed by FESEM and AFM. Moreover, immersion of the stainless steel in the silane solution with pH 2.1, characterized by higher hydrolysis ratio, led to more effective corrosion control in the NaCl electrolyte according to the results of electrochemical noise and FTIR measurements.
Research limitations/implications
The noise resistance and characteristic charge as electrochemical noise parameters were only used in this research to evaluate the protective behavior of the water-based silane sol-gel coatings. Future studies should examine the correlation between electrochemical noise data and the parameters extracted from other electrochemical methods, e.g. electrochemical impedance spectroscopy.
Practical implications
The data obtained in this research may provide an effective approach based on electrochemical noise method to screen the silane sol-gel coatings for protection of metallic substrates against corrosion.
Originality/value
According to the literature, no report can be found studying the effect of immersion time on a silane solution, including glycidyloxypropyltrimethoxysilane, tetraethoxysilane and methyltriethoxysilane, as well as the silane solution pH on the corrosion resistance of 304L stainless steel in NaCl solution through electrochemical noise method.
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The purpose of this paper is to evaluate and compare the protective, anticorrosion properties of silane- and polyrhodanine-based bilayer coatings pRh/IBTES and IBTES/pRh on an…
Abstract
Purpose
The purpose of this paper is to evaluate and compare the protective, anticorrosion properties of silane- and polyrhodanine-based bilayer coatings pRh/IBTES and IBTES/pRh on an X20Cr13 stainless steel substrate.
Design/methodology/approach
IBTES/pRh and pRh/IBTES have been coated using the dip-coating method and the cyclic voltammetry technique. The electrochemical measurements have been used to assess the anticorrosion properties of the resulting bilayer coatings. Morphological and chemical characterizations have been performed using scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS).
Findings
The results clearly show that the combination of both the deposits of polyrhodanine and silane yields a more protective structure that affords better protection against corrosion with time. The best barrier properties are achieved by the substrates coated with polyrhodanine film upon which silane is subsequently adsorbed – the pRh/IBTES bilayer coating.
Originality/value
The paper reveals that the procedure of modification of silane films with polyrhodanine had a marked effect on the anti-corrosive performance of the obtained two types of bilayers coatings (pRh/IBTES, IBTES/pRh) applied on a stainless steel surface. The coating where polyrhodanine was first electrodeposited on the steel surface and then the silane layer adsorbed (pRh/IBTES) achieved the best protective properties.
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Mubarak Ali, Esah Hamzah and Mohammad Radzi Toff
The purpose of this paper is to examine the effect of substrate temperature on friction coefficient and surface roughness of titanium nitride (TiN) coatings deposited on…
Abstract
Purpose
The purpose of this paper is to examine the effect of substrate temperature on friction coefficient and surface roughness of titanium nitride (TiN) coatings deposited on high‐speed steel (HSS) using commercially available cathodic arc evaporation physical vapour deposition system.
Design/methodology/approach
The goal of this work is to determine the usefulness of TiN coatings in order to improve the friction coefficient and surface roughness of HSS verses substrate temperature, as vastly used in cutting tool industry and many others. A Pin‐on‐Disc test was carried out to study the coefficient of friction verses sliding distance. Surface roughness of deposited coatings was studied via surface roughness tester and atomic force microscope (AFM).
Findings
Friction coefficient increased at higher temperature as compared to the coating deposited at lower substrate temperature. Surface roughness measured via both instruments showed similar trend in recorded data and, i.e. increased by increasing substrate temperature. AFM study showed that bearing ratio (per cent) decreased, whereas, fractal dimension increased with an increase in substrate temperature.
Research limitations/implications
It is implied that choosing a substrate temperature above 450°C in the existing coating system could damage some machine parts.
Practical implications
This scenario develops an approach to optimize the coating properties verses substrate temperature for specific application, such as cutting tools for automobiles and aircrafts.
Originality/value
The coating deposited at lower temperature showed better friction coefficient and surface roughness than the coating deposited at higher temperature and vice versa.
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Nivin M. Ahmed, Hassan S. Emira and Hesham M. Tawfik
Ion‐exchange clays containing sodium such as bentonite and montmorillonite have the ability to exchange their cations. Few studies conducted with this type of ion‐exchange…
Abstract
Purpose
Ion‐exchange clays containing sodium such as bentonite and montmorillonite have the ability to exchange their cations. Few studies conducted with this type of ion‐exchange pigments are not conclusive about their anticorrosive efficiency. The present research aims to address the study on the anticorrosive efficiency of this type of pigments in chlorinated rubber paints. Sodium‐bentonite was exchanged with Zn, Sr and Zn‐Sr to be applied on low carbon steel specimens and study the anticorrosive performances of these new ion‐exchanged bentonites (IEBs) in anticorrosive paint formulations.
Design/methodology/approach
The new pigments were characterised using scanning electron microscopy (SEM) and X‐ray fluorescence (XRF) to determine the CEC (cation exchange capacity) of the different exchanged cations. Evaluation of the ion‐exchanged and Na‐bentonite pigments using international standard testing methods (ASTM) was estimated. Paint systems manufactured with these ion‐exchange pigments have been subjected to adhesion, accelerated corrosion laboratory tests, and EIS in order to assess their anticorrosive behaviour.
Findings
The results of this work revealed that the ion‐exchange bentonite (IEBs) pigments showed high anticorrosive performance that can be arranged as follows: Sr‐bentonite was better than Zn‐Bentonite and both were better than the double Zn‐Sr‐bentonite indicating an antagonism behaviour between the two cations when present together.
Practical implications
These pigments can be applied in other polymer composites, e.g. rubber and plastics as reinforcing agent and fillers.
Originality/value
These prepared pigments are environmentally friendly pigments which impart high anticorrosive behaviour to paint films with great economic savings.
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Shengsong Ge, Menglong Li, Qian Shao, Ke Liu, Junxiang Wang and Fengjiao Yi
This paper aims to clarify the effect of metal ions added in the γ-glycidoxypropyltrimethoxysilane (γ-GPS) solutions on the anti-corrosion properties of the γ-GPS coatings on…
Abstract
Purpose
This paper aims to clarify the effect of metal ions added in the γ-glycidoxypropyltrimethoxysilane (γ-GPS) solutions on the anti-corrosion properties of the γ-GPS coatings on cold-rolled iron (CRI).
Design/methodology/approach
The transformations of functional groups involved in reactions during the coating process were characterized by Fourier transformed infrared spectroscopy (FTIR), and the thickness of the γ-GPS coatings on the CRI substrates was measured using high-powered microscopy. The anti-corrosion properties of γ-GPS-treated samples were evaluated by neutral salt spray tests, polarization curves and electrochemical impedance spectroscopy measurements.
Findings
The results show that Zn2+ and Mg2+ in the γ-GPS solutions promote the formation of Si-O-Si and Si-O-Fe bonds and improve the anti-corrosion properties of the γ-GPS coatings on CRI. However, Al3+ and Na+ in the γ-GPS solutions do not play this role.
Originality/value
Although there have been previous research studies on the γ-GPS coatings on CRI, this paper is the first to study the effect of metal ions added in the silane solutions on the anti-corrosion properties of the γ-GPS coatings, and it has been confirmed that the anti-corrosion properties changed when Zn2+ (or Mg2+) is present.
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