Quick revision
Topic: Corrosion and its prevention
Definition: It is the process in which metals are slowly eaten up by the action of air moisture or chemicals. For example rusting is a form of corrosion in which iron is eaten up by the action of air and moisture and a reddish brown coating of iron oxide is formed as shown in the following Chemical Reaction.
Ill effects of corrosion:
Definitely there are many harmful effects of corrosion. Some of them are listed below.
- Loss of efficiency
- Contamination of product
- Damage of metallic equipment’s
- Inability to use metallic materials
- Loss of valuable materials such as blockage of pipes, mechanical damage of underground water pipes
- Accidents due to mechanical loss of metallic bridges, cars, aircrafts etc.
- Causes pollution due to escaping products from corrosion
- Depletion of natural resource ( Metals)
Methods of prevention of corrosion:
| Coating and Painting | · Iron surface is often painted with the coatings of varnish or paint to isolate it from the Environment. Window grills, bodies of automobiles, iron bridges and rails are painted regularly to protect them from rusting.
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| Applying a layer of grease |
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| Galvanisation |
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Corrosion is the deterioration of a material due to chemical or electrochemical reaction with its environment. The most common form of corrosion is oxidation, which is the loss of electrons from a material. Corrosion can cause a number of problems, including structural failure, equipment malfunction, and product degradation.
There are many different types of corrosion, each with its own causes and effects. Some of the most common types of corrosion include:
- Electrochemical corrosion: This is the most common type of corrosion and is caused by a reaction between a metal and an electrolyte, such as water. Electrochemical corrosion can occur in a variety of environments, including air, water, and Soil.
- Galvanic corrosion: This type of corrosion occurs when two dissimilar metals are in contact with each other in an electrolyte. The more active metal will corrode at a faster rate than the less active metal.
- Crevice corrosion: This type of corrosion occurs in narrow openings, such as between two metal plates or in the threads of a bolt. Crevice corrosion can be caused by a number of factors, including the presence of Oxygen, chloride ions, and organic matter.
- Pitting corrosion: This type of corrosion occurs when small pits form on the surface of a metal. Pitting corrosion can be caused by a number of factors, including the presence of chloride ions, Stress, and impurities in the metal.
- Intergranular corrosion: This type of corrosion occurs along the grain boundaries of a metal. Intergranular corrosion can be caused by a number of factors, including the presence of impurities in the metal, heat treatment, and welding.
- Stress corrosion cracking: This type of corrosion occurs when a metal is under stress and is exposed to a corrosive environment. Stress corrosion cracking can cause sudden and catastrophic failure of a metal component.
- Hydrogen embrittlement: This type of corrosion occurs when hydrogen atoms diffuse into a metal and cause it to become brittle. Hydrogen embrittlement can be caused by a number of factors, including the presence of hydrogen in the environment, cathodic protection, and welding.
- Corrosion fatigue: This type of corrosion occurs when a metal is subjected to cyclic stresses and is exposed to a corrosive environment. Corrosion fatigue can cause a metal component to fail prematurely.
There are a number of ways to prevent corrosion, including:
- Cathodic protection: This involves applying a voltage to a metal so that it becomes the cathode in an electrochemical cell. This prevents the metal from corroding.
- Anodic protection: This involves applying a voltage to a metal so that it becomes the anode in an electrochemical cell. This also prevents the metal from corroding.
- Inhibitors: These are chemicals that are added to a corrosive environment to reduce the rate of corrosion.
- Coatings: These are materials that are applied to a metal to protect it from the environment. Coatings can be organic, such as paint, or inorganic, such as galvanizing.
- Design for corrosion resistance: This involves designing metal components so that they are less likely to corrode. This can be done by using corrosion-resistant materials, by avoiding sharp corners, and by providing drainage holes.
- Inspection and maintenance: This involves regularly inspecting metal components for signs of corrosion and repairing any damage that is found.
Corrosion is a major problem that can cause a number of problems, including structural failure, equipment malfunction, and product degradation. There are a number of ways to prevent corrosion, including cathodic protection, anodic protection, inhibitors, coatings, design for corrosion resistance, and inspection and maintenance.
Corrosion
Corrosion is the deterioration of a material due to chemical or electrochemical reaction with its environment.
Types of corrosion
There are many different types of corrosion, but the most common are:
- Galvanic corrosion: This type of corrosion occurs when two dissimilar metals are in contact with each other in an electrolyte, such as water. The more active metal will corrode, while the less active metal will be protected.
- Electrochemical corrosion: This type of corrosion occurs when a metal is exposed to an electrolyte, such as water, and an electric current is passed through the electrolyte. The metal will corrode at the anode, while the cathode will be protected.
- Pitting corrosion: This type of corrosion occurs when small pits form on the surface of a metal. The pits can grow and eventually cause the metal to fail.
- Stress corrosion cracking: This type of corrosion occurs when a metal is under stress and is exposed to an environment that can cause corrosion. The stress can cause the metal to crack, and the corrosion can cause the crack to grow.
Prevention of corrosion
There are many ways to prevent corrosion, including:
- Using a corrosion-resistant material: Some materials, such as stainless steel, are more resistant to corrosion than others.
- Applying a protective coating: A protective coating, such as paint or a sealant, can help to prevent corrosion.
- Cathodic protection: Cathodic protection is a method of protecting a metal from corrosion by applying a small electric current to the metal. The current causes the metal to become the cathode in an electrochemical cell, and the cathode is not corroded.
- Avoiding contact with corrosive materials: If possible, it is best to avoid contact with materials that can cause corrosion.
- Maintaining a clean environment: A clean environment will help to prevent corrosion.
FAQs
What is corrosion?
Corrosion is the deterioration of a material due to chemical or electrochemical reaction with its environment.
What are the different types of corrosion?
There are many different types of corrosion, but the most common are:
- Galvanic corrosion: This type of corrosion occurs when two dissimilar metals are in contact with each other in an electrolyte, such as water. The more active metal will corrode, while the less active metal will be protected.
- Electrochemical corrosion: This type of corrosion occurs when a metal is exposed to an electrolyte, such as water, and an electric current is passed through the electrolyte. The metal will corrode at the anode, while the cathode will be protected.
- Pitting corrosion: This type of corrosion occurs when small pits form on the surface of a metal. The pits can grow and eventually cause the metal to fail.
- Stress corrosion cracking: This type of corrosion occurs when a metal is under stress and is exposed to an environment that can cause corrosion. The stress can cause the metal to crack, and the corrosion can cause the crack to grow.
How can corrosion be prevented?
There are many ways to prevent corrosion, including:
- Using a corrosion-resistant material: Some materials, such as stainless steel, are more resistant to corrosion than others.
- Applying a protective coating: A protective coating, such as paint or a sealant, can help to prevent corrosion.
- Cathodic protection: Cathodic protection is a method of protecting a metal from corrosion by applying a small electric current to the metal. The current causes the metal to become the cathode in an electrochemical cell, and the cathode is not corroded.
- Avoiding contact with corrosive materials: If possible, it is best to avoid contact with materials that can cause corrosion.
- Maintaining a clean environment: A clean environment will help to prevent corrosion.
What are the consequences of corrosion?
Corrosion can have many negative consequences, including:
- Loss of material: Corrosion can cause a material to lose mass, which can lead to failure.
- Degradation of performance: Corrosion can degrade the performance of a material, which can lead to failure.
- Increased costs: Corrosion can increase the costs of maintenance and repair.
- Environmental damage: Corrosion can damage the environment, such as by releasing pollutants into the air or water.
1. What is corrosion?
Corrosion is the deterioration of a material due to chemical or electrochemical reaction with its environment.
2. What are the different types of corrosion?
There are many different types of corrosion, but some of the most common include:
- Galvanic corrosion: This type of corrosion occurs when two dissimilar metals are in contact with each other and are exposed to an electrolyte, such as water. The more active metal will corrode, while the less active metal will be protected.
- Uniform corrosion: This type of corrosion occurs evenly over the surface of a metal. It is the most common type of corrosion and can be caused by a variety of factors, including exposure to moisture, oxygen, and acids.
- Pitting corrosion: This type of corrosion occurs when small pits form on the surface of a metal. The pits can grow over time and eventually cause the metal to fail. Pitting corrosion is often caused by exposure to chloride ions, such as those found in seawater.
- Intergranular corrosion: This type of corrosion occurs at the grain boundaries of a metal. It is often caused by the presence of impurities in the metal or by exposure to certain chemicals. Intergranular corrosion can cause the metal to fail suddenly and without warning.
3. What are the causes of corrosion?
The causes of corrosion can vary depending on the type of corrosion. However, some of the most common causes include:
- Exposure to moisture: Moisture is one of the most common causes of corrosion. When metal is exposed to moisture, it can react with oxygen to form rust.
- Exposure to oxygen: Oxygen is another common cause of corrosion. When metal is exposed to oxygen, it can react with the metal to form oxides.
- Exposure to acids: Acids can cause corrosion by dissolving the metal.
- Exposure to salts: Salts can cause corrosion by breaking down the protective oxide layer on the metal.
4. How can corrosion be prevented?
There are a number of ways to prevent corrosion, including:
- Applying a protective coating: A protective coating can help to prevent corrosion by forming a barrier between the metal and the environment.
- Using corrosion-resistant materials: Some materials are more resistant to corrosion than others. Using corrosion-resistant materials can help to reduce the risk of corrosion.
- Avoiding exposure to corrosive environments: If possible, it is best to avoid exposing metal to corrosive environments. However, if this is not possible, other methods can be used to protect the metal.
5. What are the effects of corrosion?
Corrosion can have a number of negative effects, including:
- Deterioration of the metal: Corrosion can cause the metal to deteriorate and weaken. This can lead to failure of the metal.
- Loss of material: Corrosion can cause the metal to lose material. This can lead to a reduction in the size and strength of the metal.
- Increased costs: Corrosion can lead to increased costs, such as the cost of repairing or replacing the metal.
- Environmental damage: Corrosion can release harmful pollutants into the environment.
6. What is the importance of corrosion prevention?
Corrosion prevention is important because it can help to protect metal from damage and failure. This can lead to a number of benefits, such as:
- Reduced costs: Corrosion prevention can help to reduce the costs associated with repairing or replacing damaged metal.
- Increased safety: Corrosion prevention can help to increase safety by reducing the risk of metal failure.
- Improved performance: Corrosion prevention can help to improve the performance of metal by reducing the risk of damage.
- Protection of the environment: Corrosion prevention can help to protect the environment by reducing the release of harmful pollutants.