What is Corrosion?
Corrosion is the gradual destruction or deterioration of metals and alloys due to chemical or
electrochemical reactions with their environment. It results in material loss, structural weakening,
and failure of metallic components.
Types of Corrosion
1. Uniform Corrosion - Evenly distributed over the entire surface.
2. Galvanic Corrosion - Occurs when two different metals are in electrical contact in an electrolyte.
3. Pitting Corrosion - Localized corrosion forming small holes or pits.
4. Crevice Corrosion - Occurs in narrow gaps or crevices where oxygen supply is limited.
5. Intergranular Corrosion - Attacks grain boundaries of metals, weakening the structure.
6. Stress Corrosion Cracking (SCC) - Cracks form due to a combination of tensile stress and a
corrosive environment.
7. Erosion Corrosion - Caused by mechanical wear combined with chemical attack.
8. Microbiologically Influenced Corrosion (MIC) - Caused by bacterial activity.
Factors Affecting Corrosion
- Environmental Conditions: Humidity, temperature, pH levels.
- Material Composition: Type of metal or alloy used.
- Presence of Impurities: Contaminants that accelerate corrosion.
- Electrochemical Reactions: Interaction with oxygen, water, and salts.
Corrosion Prevention Methods
1. Protective Coatings: Paints, polymers, and oxide layers.
2. Cathodic Protection: Using sacrificial anodes or impressed current systems.
3. Alloying: Adding elements like chromium in stainless steel.