Crevice corrosion | EPFL Graph Search

Are you an EPFL student looking for a semester project?

Work with us on data science and visualisation projects, and deploy your project as an app on top of GraphSearch.

Crevice corrosion refers to corrosion occurring in occluded spaces such as interstices in which a stagnant solution is trapped and not renewed. These spaces are generally called crevices. Examples of crevices are gaps and contact areas between parts, under gaskets or seals, inside cracks and seams, spaces filled with deposits and under sludge piles. The corrosion resistance of a stainless steel is dependent on the presence of an ultra-thin protective oxide film (passive film) on its surface, but it is possible under certain conditions for this oxide film to break down, for example in halide solutions or reducing acids. Areas where the oxide film can break down can also sometimes be the result of the way components are designed, for example under gaskets, in sharp re-entrant corners or associated with incomplete weld penetration or overlapping surfaces. These can all form crevices which can promote corrosion. To function as a corrosion site, a crevice has to be of sufficient width to permit entry of the corrodent, but narrow enough to ensure that the corrodent remains stagnant. Accordingly crevice corrosion usually occurs in gaps a few micrometres wide, and is not found in grooves or slots in which circulation of the corrodent is possible. This problem can often be overcome by paying attention to the design of the component, in particular to avoiding formation of crevices or at least keeping them as open as possible. Crevice corrosion is a very similar mechanism to pitting corrosion; alloys resistant to one are generally resistant to both. Crevice corrosion can be viewed as a less severe form of localized corrosion when compared with pitting. The depth of penetration and the rate of propagation in pitting corrosion are significantly greater than in crevice corrosion. Crevices can develop a local chemistry which is very different from that of the bulk fluid. For example, in boilers, concentration of non-volatile impurities may occur in crevices near heat-transfer surfaces because of the continuous water vaporization.

About this result

This page is automatically generated and may contain information that is not correct, complete, up-to-date, or relevant to your search query. The same applies to every other page on this website. Please make sure to verify the information with EPFL's official sources.

Related publications (2)

Related concepts (3)

Related courses (13)

Related lectures (68)

Crevice corrosion

Corrosion

Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engineering is the field dedicated to controlling and preventing corrosion. In the most common use of the word, this means electrochemical oxidation of metal in reaction with an oxidant such as oxygen, hydrogen or hydroxide. Rusting, the formation of iron oxides, is a well-known example of electrochemical corrosion.

Stainless steel

Stainless steel, also known as inox or corrosion-resistant steel (CRES), is an alloy of iron that is resistant to rusting and corrosion. It contains at least 10.5% chromium and usually nickel, and may also contain other elements, such as carbon, to obtain the desired properties. Stainless steel's resistance to corrosion results from the chromium, which forms a passive film that can protect the material and self-heal in the presence of oxygen. The alloy's properties, such as luster and resistance to corrosion, are useful in many applications.

A Crevice Corrosion Model for Biomedical Trunnion Geometries and Surfaces Feature

Stefano Mischler, Angela Bermudez Castañeda

Modular hip joint implants were introduced in arthroplasty medical procedures because they facilitate the tailoring of patients’ anatomy, the use of different materials in one single configuration, as well as medical revision. However, in certain cases, such prostheses may undergo deterioration at the head–neck junctions with negative clinical consequences. Crevice-corrosion is commonly invoked as one of the degradation mechanisms acting at those junctions despite biomedical alloys such as Ti6Al4V and CoCr being considered generally resistant to this form of corrosion. To verify the occurrence of crevice corrosion in modular hip joint junctions, laboratory crevice-corrosion tests were conducted in this work under hip joint-relevant conditions, i.e., using similar convergent crevice geometries, materials (Ti6Al4V and CoCr alloys vs. ceramic), surface finish, NaCl solution pHs (5.6 and 2.3), and electrochemical conditions. A theoretical model was also developed to describe crevice-corrosion considering relevant geometrical and electrochemical parameters. To verify the model, a FeCr alloy, known to be sensitive to this phenomenon, was subjected to the crevice-corrosion test in sulfuric acid. The experiments and the model predictions clearly showed that, in principle, crevice corrosion of Ti6Al4V or CoCr is not supposed to occur in typical crevices formed at the stem-neck junction of hip implants

2021

Silicon Corrosion in Neutral Media: The Influence of Confined Geometries and Crevice Corrosion in Simulated Physiological Solutions

Stefano Mischler, Patrik Schmutz, Roland Hauert, Emilija Ilic

Silicon (Si) based implantable components are widely used to restore functionalities in the human body. However, there have been reported instances of Si corroding after only a few years of implantation. A key parameter often overlooked when assessing Si stability in-vitro, is the added constricting geometries introduced through in-vivo implantation. The influence of crevices and confined solutions on the stability of Si is presented in this study, considering two simulated physiological solutions: 0.01 M phosphate buffered saline (PBS) and HyClone Wear Test Fluid (WTF). It was found that Si is highly vulnerable to corrosion in confined/crevice conditions. High pitting corrosion susceptibility is found in a crevice, whereas a dissolution rate of ca. 3.6 nm/h at body temperature occurred due to local alkalization within a confined cathodic area. The corrosion rates could be increased by elevating the temperature and yielded linear Arrhenius relations, with activation energies of 106 KJ/mol in 0.01MPBS and 109 KJ/mol in HyClone WTF, corresponding to a phosphorous-silicon interaction mechanism. Phosphorous species favored corrosion and contributed to enhanced Si dissolution, while chlorides were not so influential, and applied anodic potential induced pseudo-passivation. These results highlight the importance geometrical configurations can have on a material's surface stability. (c) The Author(s) 2019. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited.

2019

MSE-311: Corrosion and protection of metals + Laboratory Work

Ce cours d'introduction à la corrosion veut familiariser l'étudiant avec les mécanismes réactionnels de la corrosion, avec les différentes formes de corrosion et avec les principes de la protection co

MSE-658: Electrochemistry in Corrosion Research

This course introduces the basic principles of electrochemistry, focusing on corrosion research. It covers the basics of corrosion testing and monitoring techniques, such as linear polarization, cycli

MSE-627: X-Ray Analysis for thin films

Intro into the relation between physical and structural properties; introduction into different X-Ray techniques; examples of successful technological transfer using X-Ray techniques; Structural prope

Concrete Durability: Mechanisms and Prevention MSE-322: Building materials + Laboratory work

Explores concrete degradation mechanisms, corrosion prevention, exposure classes, and repair techniques for reinforced concrete structures.

Thermo-Calc: Exercise and Property Models MSE-422: Advanced metallurgy

Explores Thermo-Calc software for defining functions and property models in materials science.

Redox Reactions: Predominance Diagrams ENV-200: Environmental chemistry

Covers the solubility of metal hydroxides, redox reactions in aquatic systems, arsenic mobilization, water treatment, and the Nernst equation application.