"Corrosion is a natural process that converts a refined metal into a more chemically stable oxide."
The deterioration or degradation of metallic components and structures due to chemical or electrochemical reactions with their environment.
Chemical and electrochemical reactions: Understanding the basic chemical and electrochemical reactions that occur during corrosion is essential as it lays the foundation for further knowledge.
Types of corrosion: There are various types of corrosion, including uniform corrosion, localized corrosion, and galvanic corrosion. Understanding each type and how it occurs is crucial for predicting and preventing corrosion.
Corrosion prevention methods: Various methods can be used to prevent corrosion, including coating methods, cathodic protection, and inhibitors. A knowledge of these methods is necessary to choose the most suitable method for a specific situation.
Corrosion monitoring: Corrosion monitoring techniques are used to assess the rate and extent of corrosion. This knowledge helps to determine the most effective prevention method.
Corrosion testing: Testing methods for corrosion resistance and prevention are necessary to qualify materials for a specific application. Understanding these methods is essential for the selection and use of materials in various corrosive environments.
Material selection: Choosing the most appropriate material for a specific environment is essential to prevent corrosion. Knowledge of materials, their properties, and their susceptibility to corrosion is paramount.
Corrosion in specific environments: Different environments, such as marine, chemical, and atmospheric, have varying corrosive tendencies. Understanding the unique features and effects of each environment is necessary to prevent or mitigate corrosion.
Corrosion in specific industries: Corrosion has a significant impact on industries such as oil and gas, aerospace, and automotive. Understanding the specific corrosion challenges and prevention methods in each industry is crucial.
Corrosion control and management: The management of corrosion involves the identification, assessment, and prevention of corrosion problems. Knowledge of corrosion control techniques is necessary to implement effective management strategies.
Corrosion standards and regulations: Standards and regulations are set to ensure the quality and reliability of materials used in various applications. A knowledge of these standards is beneficial for material selection and corrosion prevention.
Uniform corrosion: Occurs evenly across the surface of a material, resulting in a decrease in thickness.
Galvanic corrosion: Occurs when two dissimilar metals are in contact with each other in the presence of an electrolyte, causing the more reactive metal to corrode.
Pitting corrosion: Localised and focused corrosion that produces pits or small holes on the surface of a material.
Crevice corrosion: Occurs when a small gap or crevice is present between two surfaces, concentrating the electrolyte and leading to corrosion.
Intergranular corrosion: Occurs at the grain boundaries of a material, usually as a result of improper heat treatment or welding.
Selective leaching: When a more reactive element in a material is preferentially corroded, leading to an uneven surface.
Erosion-corrosion: When a material is corroded due to the combined effect of oxidation and mechanical wear and tear.
Stress corrosion cracking: Occurs under tensile stress in the presence of a corrosive environment, leading to the formation and propagation of cracks.
Fretting corrosion: A type of corrosion that occurs between two surfaces that are under slight relative movement.
Microbial corrosion: Corrosion caused by microorganisms in a material's environment.
"...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."
"Corrosion can also occur in materials other than metals, such as ceramics or polymers, although in this context, the term 'degradation' is more common."
"Corrosion degrades the useful properties of materials and structures including mechanical strength, appearance, and permeability to liquids and gases."
"The process can be strongly affected by exposure to certain substances."
"Corrosion is a diffusion-controlled process, it occurs on exposed surfaces."
"Methods to reduce the activity of the exposed surface, such as passivation and chromate conversion, can increase a material's corrosion resistance."
"However, some corrosion mechanisms are less visible and less predictable."
"The chemistry of corrosion is complex; it can be considered an electrochemical phenomenon."
"During corrosion at a particular spot on the surface of an object made of iron, oxidation takes place and that spot behaves as an anode."
"The electrons released at this anodic spot move through the metal to another spot on the object."
"And reduce oxygen at that spot in presence of H+."
"Which is believed to be available from carbonic acid formed due to dissolution of carbon dioxide from air into water in moist air condition of atmosphere."
"Hydrogen ion in water may also be available due to dissolution of other acidic oxides from the atmosphere."
"This spot behaves as a cathode."
"Corrosion degrades... appearance."
"Corrosion degrades... permeability to liquids and gases."