Description
S355K2W – Medium Tensile Weathering Steel
Table of Contents
- Introduction to S355K2W
- Chemical Composition
- Mechanical Properties
- Applications of S355K2W
- Comparison with Other Grades
- Corrosion Resistance
- Welding and Fabrication
- Conclusion
1. Introduction to S355K2W
S355K2W is a medium tensile, low carbon manganese weathering steel designed for durability and versatility. Known for its excellent weldability and good impact resistance—even at sub-zero temperatures—this steel grade is ideal for various structural applications. Commonly supplied in an untreated or normalized condition, S355K2W forms a protective rust layer when exposed to the elements, enhancing its corrosion resistance over time.
2. Chemical Composition
The specific chemical composition of S355K2W plays a vital role in its mechanical properties. Typical elements include:
- Carbon (C): ≤ 0.20%
- Manganese (Mn): 1.00 – 1.50%
- Phosphorus (P): ≤ 0.045%
- Sulfur (S): ≤ 0.045%
- Copper (Cu): 0.25 – 0.55%
- Iron (Fe): Balance
This combination ensures that S355K2W can develop a stable protective patina, safeguarding it against further corrosion.
3. Mechanical Properties
S355K2W exhibits impressive mechanical properties, making it suitable for demanding applications:
| Property | Value |
|---|---|
| Yield Strength (min) | 355 MPa |
| Tensile Strength | 480 – 620 MPa |
| Elongation (min) | 22% |
| Impact Energy (at -20°C) | 27 J (minimum) |
These properties allow S355K2W to withstand significant loads and stresses, ensuring structural integrity.
4. Applications of S355K2W
S355K2W is utilized across various industries due to its robust properties and aesthetic appeal. Common applications include:
- Bridges: Ideal for constructing long-lasting and durable bridges.
- Rail Infrastructure: Used in railway applications for its strength and reliability.
- Architectural Applications: Favored in modern architecture for its visual appeal and durability.
- Offshore Structures: Suitable for marine applications, providing resistance to harsh conditions.
The versatility of S355K2W makes it an excellent choice for both functional and aesthetic applications.
5. Comparison with Other Grades
S355K2W can be compared with other steel grades to highlight its unique features:
| Grade | Yield Strength | Corrosion Resistance | Typical Applications |
|---|---|---|---|
| S355K2W | 355 MPa | Excellent | Bridges, rail, offshore |
| S235JR | 235 MPa | Poor | General construction |
| S355J2 | 355 MPa | Moderate | Heavy-duty structures |
S355K2W stands out for its combination of strength and weather resistance, making it particularly suited for outdoor applications.
6. Corrosion Resistance
One of the key benefits of S355K2W is its excellent corrosion resistance. When exposed to atmospheric conditions, it forms a protective rust layer that acts as a barrier against further deterioration. This feature is particularly advantageous for structures exposed to harsh environmental conditions, reducing the need for maintenance and prolonging service life.
7. Welding and Fabrication
Welding S355K2W is straightforward due to its low carbon content. It can be joined using various techniques, such as:
- MIG/MAG Welding
- TIG Welding
- Submerged Arc Welding
Using compatible filler materials is essential to maintain corrosion resistance and ensure strong weld joints. Following recommended preheating and post-weld treatments can help avoid cracking and ensure structural integrity.
