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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.

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.

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.

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.

The purpose of this paper is to clarify the influence of bicarbonate, chloride and outer electrode potential on crevice corrosion occurrence and development of X70 steel.

The crevice corrosion behavior in NaHCO₃ and NaCl solutions was investigated through modeling and experiments. The electrode potential and current density distribution were simulated, and the acidification of crevice solution was monitored in situ.

The bicarbonate concentration and outer electrode potential remarkably influenced the occurrence of crevice corrosion. The former changes the passivation curves, and the latter alters the initial potential. Moreover, chloride concentration exerted minimal influence. The location of acidification and pitting occurrences depended on the potential difference between the outer electrode and electrode at the active dissolution current peak.

This study provides a better understanding of the crevice corrosion behavior and mechanism under natural conditions.

This study aims to propose a simple experimental method to distinguish the galvanic corrosion, crevice corrosion and self-corrosion in metal/carbon fiber reinforced polymer (CFRP) joints.

The corrosion behaviors of four different galvanic couples, whose anodes were Zn-coated DP590 steel and Al 6022, and cathodes were two kinds of CFRP, were investigated in immersion and GMW14872 cyclic conditions.

The results showed that the galvanic corrosion caused by direct contact between CFRP and metals was more serious than that caused by the jointing bolts. The corrosion damage caused by crevice corrosion was severer than that caused by galvanic corrosion. Self-corrosion was also significant, particularly under the cyclic salt spray condition.

Cyclic salt spray test may more reliably simulate the galvanic corrosion of a joint in industrial service environments, and real corrosion damage may be underestimated by a galvanic current measurement.

A deeper understanding of different corrosion mechanisms involved in CFRP/metal joints under different service conditions in industry has been given.

Under severely aggressive conditions, such as those experienced in the chemical industry, there has been extensive use of stainless steels in order to reduce corrosion losses. The successful industrial use of stainless steels led to requests for information on the corrosion resistance of stainless steels and similar alloys in sea‐water. This paper was awarded a prize in the Essay competition organised by the Corrosion Group of the Society of Chemical Industry, 1959.

Introduction There is no need to emphasize the problems that corrosion can cause. It is like a cancer cell, sometimes slowly developing for many years undetected and then once observed it is too late to eliminate. The best course of action at that stage being to try and contain it. Corrosion is a very complex chemical action involving a metal with its environment and it is rare for all the various circumstances to repeat themselves, resulting in an identical corrosion situation.

Until recently, chlorine used to be an important chemical in bleaching process in paper industry, but as a result of environmental concerns, it is being replaced by chlorine dioxide. However, chlorine dioxide is more corrosive in certain conditions. Plant personnel, therefore need to better understand the reactions taking place in the changed media and search for more resistant materials. It is with this in mind that the present work was undertaken. The paper reports the electrochemical polarisation measurements performed on stainless steels 316L, 317L, 2205 and 254SMO in chlorine dioxide solutions to observe localised corrosion. The results have been analysed with reference to Pourbaix diagrams, taking into account the various chemical species present in the bleach solutions. Conclusions drawn from electrochemical tests have been compared with those from long‐term laboratory and plant tests. Materials options are proposed on the optimal choice of materials for bleach plants, in a context of probable corrosion performance, capital cost and mechanical strength.

The purpose of this paper is to determine the failure reasons and failure mechanism of the commercially pure titanium air conditioning condenser.

In this paper, chemical analysis, metallographic observation, visual examination and scanning electron microscope examination, corrosion products analysis and working conditions analysis were adopted for determining the reasons for the failure of the condenser.

The results indicated that TA2 titanium pipe perforation failure is caused by the synergistic effect of crevice corrosion and deposit corrosion. The corrosion processes can be divided into three steps.

This research is an originality study on the failure case of a commercially pure titanium air conditioning condenser. This study makes up for the shortage of titanium alloy failure cases and also gives the result of the failure reason and failure mechanism for titanium, which has an engineering significance.

Introduction Although nickel is generally regarded as a corrosion resistant material its resistance to sea water is only moderate. In fast flowing sea water its corrosion rate is very low; of the order of 0.0005 in/yr. Under stagnant conditions, however, it is susceptible to pitting and crevice corrosion attack. Consequently, alloying has been a common method of improving corrosion resistance to obtain a material having the excellent resistance of nickel to fast flowing sea water together with an improved resistance to pitting corrosion.

Explains corrosion protection and how it works. Discusses the effect of environmental legislation on corrosion protective paints, which necessitates the removal of solvents and toxic additives, making the protection weaker. In order to remedy this one must determine how protection is provided, which involves the separation of barrier properties and electrochemical passivation. Describes methods and tests involved in this and discusses the results. Concludes with recommendations and a suggestion for further tests.

Selecting the most suitable, cost‐efficient alloy for a given application should not be difficult if the methodology described in this paper is followed. The first step is to identify those alloys with the desired corrosion resistance. Factors other than chemical composition have a bearing on an alloy’s corrosion resistance. Service environment and nature of the product application must also be considered. These conditions are discussed in the text. Consideration should be given to other key issues such as mechanical properties required as well as method of fabrication, design, condition and availability of the candidate alloy. To simplify selection, the author discusses severe corrodents and aggressive environments that are commonly encountered in the process industries, and describes the characteristics of alloys that might be considered for each type of corrosive service. Cross referenced charts position these alloys to show their relative resistance to each type of corrosion attack. While the paper is not designed to replace the technical expertise of a corrosion engineer, the author feels it can serve as a good starting point in the alloy selection process.