S355jow
S355JOW steel plate is a weather-resistant structural steel designed for outdoor environments. Its copper, chromium, and nickel alloying elements enable the formation of a protective rust layer that significantly improves atmospheric corrosion resistance. It is widely used in bridges, building structures, transportation systems, and outdoor engineering projects where durability and low maintenance are required.
- Description
S355JOW is a low-alloy structural weather-resistant steel grade designed for outdoor and atmospheric exposure environments. It belongs to the EN 10025-5 weathering steel family and is engineered to form a stable protective rust layer (patina) that reduces further corrosion without the need for painting in many applications.
Compared with standard structural steels like S235 or S355JR, S355JOW offers significantly improved corrosion resistance in atmospheric conditions.
Chemical Composition of S355JOW Steel Plate
The corrosion resistance of S355JOW is achieved by adding alloying elements such as copper, chromium, nickel, and phosphorus.
| Element | Content (%) |
|---|---|
| Carbon (C) | ≤ 0.12 |
| Manganese (Mn) | ≤ 1.00–1.50 |
| Silicon (Si) | ≤ 0.75 |
| Phosphorus (P) | 0.06–0.15 |
| Sulfur (S) | ≤ 0.03 |
| Chromium (Cr) | 0.30–1.25 |
| Nickel (Ni) | 0.20–0.65 |
| Copper (Cu) | 0.25–0.55 |
| Iron (Fe) | Balance |
Mechanical Properties of S355JOW
S355JOW provides good strength and toughness for structural applications.
| Property | Typical Value |
|---|---|
| Yield Strength | ≥ 355 MPa |
| Tensile Strength | 470–630 MPa |
| Elongation | ≥ 20% |
| Impact Toughness | Good (depending on thickness and condition) |
| Density | 7.85 g/cm³ |
Main Performance Features
1. Excellent Weather Resistance
S355JOW is designed to form a dense oxide layer (patina) when exposed to alternating wet and dry atmospheric conditions. This layer:
- Protects the base metal from further corrosion
- Reduces maintenance requirements
- Eliminates or reduces the need for painting
2. Good Structural Strength
With a minimum yield strength of 355 MPa, S355JOW is suitable for load-bearing structural applications such as bridges, buildings, and outdoor frameworks.
3. Stable Long-Term Durability
The alloying elements (Cu, Cr, Ni, P) improve long-term corrosion stability, especially in:
- Urban environments
- Industrial atmospheres
- Outdoor structural systems
4. Good Weldability and Fabrication
S355JOW can be processed using standard structural steel fabrication methods:
- Welding (with proper procedure control)
- Cutting
- Bending
- Drilling
- Rolling
Preheating may be required depending on thickness.
Common Applications of S355JOW Steel Plate
S355JOW is widely used in outdoor and structural engineering projects where weather resistance is important.
Typical applications include:
- Bridges and bridge structures
- Railway infrastructure
- Outdoor steel frameworks
- Building facades and architectural structures
- Shipping containers
- Industrial chimneys
- Transmission towers
- Steel sculptures and landscape structures
- Highway barriers and guardrails
- Structural support systems in outdoor environments
S355JOW vs S355JR
| Property | S355JOW (Weathering Steel) | S355JR (Structural Steel) |
|---|---|---|
| Corrosion Resistance | High (self-protecting patina) | Standard |
| Surface Protection | No painting often needed | Requires coating/painting |
| Alloy Elements | Cu, Cr, Ni added | Minimal alloying |
| Maintenance Cost | Lower | Higher |
| Typical Use | Outdoor structures | General structural use |
