Carbon Steel（碳鋼）

Carbon steel refers to steel whose main components are iron (Fe) and carbon (C), typically containing no or only trace amounts of alloying elements. It is the most common and widely used type of steel.

 

🔍 Classification of Carbon Steel (by Carbon Content)

🔍 Characteristics of Carbon Steel

• Cost-effective: Carbon steel is relatively inexpensive to produce, making it ideal for a wide range of industrial and construction applications.
• High Strength: Particularly medium and high carbon steels offer excellent strength and load-bearing capacity.
• Easy to Process: Low carbon steel is easy to machine, weld, and form.
• Low Corrosion Resistance: Carbon steel is prone to rust, so it often requires surface treatment such as painting, galvanizing, or coating.

 

🔍 Common Grades and Uses of Carbon Steel

 

🔍 Common Surface Treatments

• Hot-dip Galvanizing: Coated with a zinc layer for corrosion protection.
• Blackening: Forms an oxide film to prevent rust and reduce light reflection.
• Phosphate Coating: Enhances paint adhesion and rust resistance.
• Painting or Powder Coating: Provides protection and enhances appearance.

🔍 Characteristics of Alloy Steel

• High Performance: By adding various alloying elements, alloy steel exhibits enhanced mechanical properties, such as improved strength, toughness, and wear resistance.
• Enhanced Corrosion Resistance: Certain alloying elements (such as chromium, nickel, molybdenum) significantly improve corrosion resistance, making it suitable for harsh environments.
• High Cost: Due to the use of alloying elements and complex processing, alloy steel is more expensive than carbon steel.

 

🔍 Common Grades and Uses of Alloy Steel

 

🔍 Heat Treatment of Alloy Steel

• Quenching: Improves hardness and wear resistance.
• Tempering: Eliminates stress after quenching and increases toughness.
• Annealing: Reduces hardness, improves machinability.

🔍 Application Fields of Alloy Steel

• Automotive Industry: Used to manufacture gears, axles, connecting rods, and other parts that require high strength and wear resistance.
• Machinery Manufacturing: Ideal for high-load, high-speed, and high-wear mechanical components.
• Petrochemical Industry: Used in high-pressure vessels, pipelines, and equipment components resistant to high temperatures and corrosion.
• Aerospace: Advanced alloy steels are used in aircraft structural parts and engines.

 

📌 Summary

Alloy steel enhances its mechanical and corrosion-resistant properties by adding alloying elements, making it an indispensable material in fields requiring high performance. Although the cost is relatively high, its excellent performance makes it irreplaceable in many critical components.

🔧 Carbon Steel vs Alloy Steel vs Stainless Steel

✅ Summary