1. Weathering Properties:
Corrosion Resistance:
A36 Steel (ASTM A36): A low-carbon structural steel with no inherent corrosion resistance. Exposed surfaces rust readily, requiring protective coatings (e.g., paint) to prevent deterioration.
Corten Steel (ASTM A588): A weathering steel alloyed with copper, chromium, and nickel. Forms a stable, adherent rust layer (patina) when exposed to wet/dry cycles, significantly slowing further corrosion. Not ideal for chloride-rich environments (e.g., coastal areas), where patina formation may be disrupted.
Maintenance:
A36: Requires regular maintenance (painting/coating) to prevent structural degradation from rust.
Corten: Minimal maintenance once patina forms, though initial rust runoff may stain surrounding materials. Lifetime costs are lower due to reduced upkeep.
2. Structural Properties:
Strength:
A36: Yield strength = 36 ksi (250 MPa), tensile strength = 58–80 ksi (400–550 MPa). Suitable for general construction where high strength is not critical.
Corten: Higher yield strength = 50 ksi (345 MPa), tensile strength = 70 ksi (483 MPa). Allows for lighter, thinner sections compared to A36, optimizing weight and material use.
Fabrication:
A36: Easier to weld and form due to simple carbon steel composition. No special procedures required.
Corten: Requires controlled welding practices (e.g., preheating, compatible electrodes) to preserve corrosion resistance. Surface rust must be cleaned before welding to ensure quality.
3. Cost Considerations:
Initial Cost: A36 is cheaper upfront. Corten costs 20–40% more due to alloying elements and specialized processing.
Lifecycle Cost: Corten’s durability and low maintenance often make it more economical over time, especially in exposed applications.
4. Applications:
A36: Used in indoor/structural frameworks, buildings, and components where corrosion is mitigated by coatings or sheltering.
Corten: Ideal for bridges, outdoor sculptures, architectural facades, and exposed structures where the rustic aesthetic is desired. Avoid in areas prone to saltwater/salt spray.
5. Environmental Impact:
A36: Higher long-term environmental impact due to repeated maintenance and coatings.
Corten: Lower lifecycle impact from reduced maintenance, though production emits more CO₂. Sustainable choice for long-term projects.
6. Aesthetics:
Corten: Prized for its weathered, reddish-brown patina, often used in design-driven projects. Staining during patina formation must be managed.
A36: Typically painted or coated, offering less visual appeal in exposed settings.
Summary:
Choose A36 for cost-sensitive, protected structures with straightforward fabrication needs.
Choose Corten for exposed, architecturally significant projects requiring minimal upkeep and higher strength-to-weight ratios, despite higher initial costs.
Just like you, 70% customers choose long-term cooperation with BBN steel not only for our good product and service quality, good reputation in the international market, but also for our experienced one-stop raw material supply and further steel processing!
