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Types of metal corrosion: From chemistry to prevention

September 13, 2025
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Metal corrosion is a natural phenomenon that causes significant economic losses to industry every year. This electrochemical process leads to the gradual destruction of metals through interaction with the environment. Understanding the different types of corrosion is crucial for selecting appropriate protective measures. This article provides a comprehensive overview of the types of corrosion, their chemical mechanisms, and control methods.

regular erosion

Special feature:

  • The most common type of corrosion

  • Regular deterioration of metal surfaces

  • predictable and measurable

Chemical mechanism:

Anodic and cathodic reactions move chaotically across the metal surface:

Anode: Fe → Fe²⁺ + 2e⁻ 
Cathode: O⁻ + 2H⁻O + 4e⁻ → 4OH⁻

Example:

  • Steel rusts due to moisture.

  • Corrosion of water pipes

Control method:

  • tincture

  • protective coating

  • Use corrosion inhibitors

galvanic corrosion

Special feature:

  • When two different metals come into electrical contact

  • The metal with the lowest reduction potential (the most active) acts as the anode.

Galvani series:

Magnesium (active) → Zinc → Aluminum → Iron → Nickel → Copper → Silver (precious metal)

Example:

  • Joining copper to steel in piping systems

  • Steel and aluminum nails

Control method:

  • The metals are insulated from each other.

  • Use of sacrificial anodes

  • Developing the right communication

Bites

Special feature:

  • severe local attacks

  • creates deep holes

  • The most dangerous types of corrosion

Mechanism:

  1. Malfunction of the protective cover

  2. Formation of hollow cells

  3. Self-reproducing cavity growth

Example:

  • Corrosion of stainless steel in chloride-containing environments

  • Destruction of chemical storage tanks

Control method:

  • Choosing the right material

  • Environmental control (reduction of corrosive ions)

  • High-quality coating

Crack erosion

Special feature:

  • Occurs in cracks and hard-to-reach places.

  • The need for stagnant electrolytes

Mechanism:

  1. Lack of oxygen in the cave

  2. Acidification of the crack environment

  3. accelerated corrosion

Example:

  • Washers and screws below

  • Metal accessories

Control method:

  • Design that closes gaps

  • The corresponding seal

  • Use durable materials.

intergranular corrosion

Special feature:

  • Attack on the grain edge

  • Low mechanical strength

  • Healthy appearance of metal surfaces

Mechanism:

  • Application of chromium carbide on stainless steel

  • Formation of chromium deficiency zones

Example:

  • Corrosion of 300 series stainless steel after welding

  • Wear of aluminum alloys

Control method:

  • Correct heat treatment

  • By using sturdy steel

  • Control of chemical composition

Corrosion and erosion

Special feature:

  • Combination of mechanical and chemical influences

  • Fluid flow increases the corrosion rate.

Mechanism:

  • Damage to the protective layer

  • Increased exposure to aggressive environments

Example:

  • Corrosion of mud pipes

  • Steam turbine blades

Control method:

  • Reduce the speed of the liquid

  • Choose solid materials

  • Correct design of hydrodynamics

Stress corrosion cracking

Special feature:

  • Combination of mechanical impact and     corrosive environment

  • Suddenly cracks appeared.

  • Very dangerous and unpredictable.

Sensitive systems:

  • Carbon steel in alkaline environments

  • Stainless steel in chlorides

  • Copper alloys in ammonia

Control method:

  • Reduction of residual stresses

  • Choosing the right material

  • Environmental control

microbiological corrosion

Special feature:

  • Microbial acceleration

  • In aquatic and terrestrial environments

  • Biofilm formation

Mechanism:

  • Bacterial  acid production

  • Create an oxygen gap

  • Production of   corrosion-resistant   compounds

Example:

  • Pipe corrosion

  • destroyed marine structures

Control method:

  • Use of     antimicrobial drugs

  • Cleaning the environment

  • cathodic protection

High-temperature corrosion

Special feature:

  • At temperatures    above    500°C

  • Formation of oxides and sulfides

  • Destruction of heat-resistant   materials

Man:

Control method:

  • Use of heat-resistant coatings

  • Suitable alloy

  • Furnace environmental control

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General approach to corrosion control

1. Material selection:

  • stainless steel

  • nickel alloy

  • Titanium and zirconium

2. Technical design:

  • Closing the gap

  • Improve  drainage

  • Reduce concentration and stress

3. Cathodic protection:

  • sacrificial anode

  • Application traffic

4. Cover:

  • Color

  • Coating

  • Ceramic coating

5. Corrosion inhibitors:

  • Organic and inorganic species

  • Adsorption mechanism

Types of metal corrosion: From chemistry to preventionbiography

Understanding the types and mechanisms of corrosion is     the first step toward effectively controlling this destructive phenomenon. While each type of corrosion requires specific preventive measures, general principles such as selecting appropriate materials, proper design, and proper surface protection apply in all cases. Given the high cost of corrosion in industry, investing in its control and prevention is crucial and cost-effective.

Important recommendations:

  1. When selecting materials, the environmental conditions should always be taken into account.

  2. Use a combination of protection methods.

  3. Create a plan for regular inspections.

  4. Consider training your employees on corrosion.

  5. Use the latest corrosion protection technologies.

By implementing these solutions, the service life of metal structures can be significantly increased and destruction caused by corrosion can be prevented.