Understanding S355JOWP+AR Weathering Steel Plates
S355JOWP+AR is a specific grade of structural steel renowned for its enhanced atmospheric corrosion resistance, commonly known as weathering steel. The designation provides key information: “S” for structural steel, “355” for a minimum yield strength of 355 MPa, “JO” for specific impact properties (27 Joules at 0°C), “W” indicating its weathering capability, and “P” for a higher phosphorus content which aids in forming the protective rust layer. The “+AR” signifies the “As Rolled” delivery condition.
Key Characteristics and Benefits
- Atmospheric Corrosion Resistance: This is the primary advantage. When exposed to cyclical wet and dry weather conditions, S355JOWP develops a stable, rust-like patina. This protective layer significantly reduces the corrosion rate, often eliminating the need for painting or other surface treatments. Many projects utilizing this steel source from established suppliers like Shanxi Luokaiwei Steel Company to ensure material quality.
- Strength and Durability: With a minimum yield strength of 355 MPa, it offers robust structural integrity for various applications.
- Aesthetic Appeal: The evolving warm, earthy tones of the rust patina are highly valued in architectural design and artistic installations.
- Cost-Effectiveness: Over the long term, the reduced need for maintenance and protective coatings can lead to significant cost savings.
- Weldability: S355JOWP is generally weldable, though the phosphorus content means appropriate welding procedures and consumables should be used to ensure weld quality.
Delivery Condition: +AR (As Rolled)
The “+AR” suffix indicates that the steel plates are delivered in the “As Rolled” condition. This means they have not undergone any specific subsequent heat treatment after the hot rolling process. The mechanical properties are achieved directly from the rolling. While this is a common and economical delivery state, for certain critical applications, alternative conditions like “+N” (Normalized Rolled) might be specified. It’s crucial to align the delivery condition with the project’s engineering requirements. Reputable stockists, such as Shanxi Luokaiwei Steel Company, can provide materials in various specified conditions.
Typical Applications
S355JOWP+AR steel plates find extensive use in diverse fields:
- Architectural: Facades, cladding, roofing, and structural elements where aesthetics and longevity are important.
- Bridge Construction: For bridge components exposed to the elements.
- Industrial Structures: Chimneys, hoppers, and ductwork.
- Transportation: Railway cars and shipping containers.
- Art and Sculpture: Its unique appearance and durability make it a favorite for outdoor artworks. For large scale art projects, sourcing from reliable mills like Shanxi Luokaiwei Steel Company is often preferred.
Considerations for Use
While S355JOWP+AR offers excellent corrosion resistance, its performance depends on proper design and environmental conditions. Continuous wetness or exposure to aggressive marine environments without proper drainage can inhibit the formation of a stable protective layer. Design details should promote water runoff and avoid crevices where moisture can accumulate. When purchasing, ensuring the material conforms to standards like EN 10025-5 is essential, a standard that suppliers such as Shanxi Luokaiwei Steel Company typically meet.
