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This study presents a numerical modeling by the finite element method of galvanic corrosion between the bolt (cathode) and the end plate (anode). The bolt is made of three types of stainless steel: austenitic (SS304L, SS316L), martensitic (SS410, SS420) and duplex (32,101), and the end plate is made of carbon steel (S235JR).

Finite element modeling.

The results obtained show, on the one hand, that this corrosion rate increases as the conductivity increases, on the other hand, the stainless steels having the highest corrosion resistance causes a considerable loss of mass of the end plate and subsequently a decrease in the lifetime of the bolted joint.

The galvanic corrosion of beam to column bolted joint with end plate, used in steel structures, was studied in order to determine the corrosion rate of the end plate and subsequently to predict the total lifetime of the bolted joint.

The poor corrosion resistance of the ferrite-pearlite steel limits its application in marine engineering because of the enhanced galvanic effect caused by continuously accumulated cementite. Cr as one principal alloying element is commonly used to improve the corrosion resistance of steels. This paper aims to study the effect of Cr on corrosion behaviors of ferrite-pearlite steels in an acidic environment.

The tested steels were immersed in a simulated solution of 10 Wt.% NaCl with pH 0.85 for 72 h to evaluate the corrosion rate. After the immersion test, the corrosion morphologies and products were tested by scanning electron microscopy, energy dispersive X-ray analysis and X-ray diffraction. Meanwhile, an electrochemical workstation was used to study the electrochemical behaviors of samples.

At the initial corrosion stage, the corrosion rate increased in the sequence of Cr₀, Cr_0.5 and Cr₁ steels, which was because of the competitive effect between the area ratio and the driving force caused by alloyed Cr. However, Cr₁ steel exhibited the best corrosion resistance after a 72-h immersion test. This was because the alloyed Cr promoted the formation of protective Fe₂O₃ and FeCr₂O₄, which suppressed the preferential dissolution of ferrite and, thus, reduced the accumulation rate of carbides, resulting in the weakened galvanic corrosion.

This paper reports the role that Cr plays in the galvanic corrosion of ferrite-pearlite steels, which is important for the engineering application of ferrite-pearlite steels in marine environment.

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.

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.

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.

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

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.

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.

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.

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.

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

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.

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.

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.

The aim of this study is to investigate the usability of horsetail, sunflower stalk, wheat stalk and corn stalk ashes as additives in paints and their performance against corrosion resistance when used.

The ashes of horsetail, sunflower stalk, wheat stalk and corn stalk were investigated in this study in single, binary and ternary combinations with three different percentages as additives in paints. Samples of concrete with any combinations of ashes resisted against the corrosion of steel reinforcements, but horsetail ash proved to be the most effective.

It can be said that these research results show that the paint containing horsetail ash is an excellent coating material that can be used in paints for the corrosion resistance of steel in reinforced concrete. The corrosion rate decreased with the increase in the amount of reactive SiO₂. There was less mass loss with the formation of resistance against corrosion in the horsetail ash added concretes. That is why horsetail ash is one of the most effective options for the aforementioned purpose.

Being cheap and easily obtainable, the materials used for coating in this study are perfect candidates for industrial use.

The purpose of this paper is to investigate the effects of chloride ion concentration and applied bias voltage on the electrochemical migration (ECM) behavior between Cu and Ag under an NaCl thin electrolyte layer (TEL).

A self-made experimental setup for the ECM behavior between Cu and Ag was designed. An HD video measurement microscopy was used to observe the typical dendrite/corrosion morphology and pH distribution. Short-circuit time (SCT), short-circuit current density and the influence of the galvanic effect between Cu and Ag on their ECM behavior were studied by electrochemical tests. The surface morphology and composition of dendrite were characterized by FESEM/EDS.

The SCT increased with increasing NaCl concentration but decreased with increasing applied bias voltage, and the SCT between Cu and Ag was less than that between Cu and Cu because their galvanic effect accelerated the dissolution and migration of Cu. When NaCl concentration was less than or equal to 6 mmol/L, cedar-like dendrite was formed, whereas no dendrite formed and only precipitation occurred at high chloride ion concentration (100 mmol/L). The composition of the dendrite between Cu and Ag was copper.

The significance of this study is to clarify the ECM failure mechanism of printed circuit board (PCB) with an immersion silver surface finish (PCB-ImAg).

This study provides a basic theoretical basis for the selection of protective measures and metal coatings for PCB.

The social implication of this study is to predict the service life of PCB.

The ECM behavior of dissimilar metals under a TEL was investigated, the influence of the galvanic effect between them on their ECM was discussed, and the SCT increased with increasing NaCl concentration.

The corrosion behaviour of titanium alloy surface when fluid with different flow rates flows through welded joints with different residual heights was explored.

The experiment uses a combination of array electrodes and simulation.

It is found that when the weld reinforcement exists, the corrosion tendency of both ends of the weld metal is greater than that of other parts of the welded joint due to the influence of high turbulence kinetic energy and shear stress. The presence of weld reinforcement heights makes the fluid behind it fluctuate greatly. The passivation films of both the base metal (BM) at the rear and the heat-affected zone (HAZ) are more prone to corrosion than those of the front BM and HAZ, and the passivation film is rougher.

The combination of test and simulation was used to explore the influence of electrochemical and hydrodynamic factors on the corrosion behaviour of titanium alloy-welded joints when welding residual height existed.

The purpose of this paper is to study the effect of current-carrying condition on the electrochemical process and atmospheric corrosion behavior of the commercial aluminum alloys.

Potentiodynamic polarization tests were performed to study the electrochemical process of the aluminum alloys. Salt spray tests and weight loss tests were carried out to study the atmospheric corrosion behavior. The corrosion morphology of the alloys was observed, and the products were analyzed.

The corrosion process of four aluminum alloys was accelerated in the current-carrying condition. Moreover, the acceleration effect on A2024 and A7075 was much stronger than that on A1050 and A5052. The main factors would be the differences in microstructure and corrosion resistance between these alloys. As the carried current increased, the corrosion rate and corrosion current density of the aluminum alloys gradually increased, with the protection of the corrosion product film decreasing linearly.

This is a recent study on the corrosion behavior of conductors under current-carrying condition, which truly understands the corrosion status of power grid materials. Relevant results provide support for the corrosion protection and safe service of aluminum alloy in power systems.

The purpose of this study is to investigate the initial corrosion behavior of pure Mg, AZ31 and AZ91 alloys in phosphate buffer solution (PBS) and to characterize the features in corrosion type and resistance of the corrosion product layer.

The scanning electron microscopy, equipped with energy-dispersive spectroscopy, X-ray photoelectron spectroscopy and electrochemical impedance spectroscopy have been used to characterize the as-corroded samples. Besides, the Mg²⁺ concentration in PBSs has been determined by inductively coupled plasma atomic emission spectrum.

It has been found that pure Mg suffers pit corrosion, and AZ31 initially undergoes pit corrosion and then uniform corrosion dominates with an extended immersion duration. However, AZ91 exhibits the uniform corrosion with the highest corrosion rate among the three materials. Besides, the corrosion product layer on AZ31 has the best compactness and corrosion resistance.

The findings add depth in understanding the corrosion of pure Mg and its alloys in PBS and also have guiding significance in exploring the effects by alloyed elements to develop new biomaterials with better performance.