Characteristics of EN10025-4 S355M Steel
Balanced High Strength and Toughness
Yield Strength: Minimum yield strength is 355 MPa for thicknesses ≤16 mm, decreasing with thickness (e.g., ≥275 MPa for 100-150 mm).
Tensile Strength: 470-630 MPa, suitable for heavy-load structures.
Elongation: ≥22%, ensuring plastic deformation capacity.
Low-Temperature Toughness: Impact energy ≥40 J at -20°C, with optional -40°C impact verification (requiring special processes) for cold-region projects.
Process-Friendly Properties
Weldability: Supports gas metal arc welding (GMAW) and submerged arc welding (SAW). Preheating ≤100°C for thicknesses <50 mm, with joint strength close to the base material.
Cold Workability: Bending (radius ≥2× plate thickness) or cutting (CNC plasma/laser cutting ≤20 mm; flame cutting >30 mm) at room temperature.
Heat Treatment: Performance optimized via normalizing, quenching, and tempering. Normalizing refines grain structure, enhancing overall properties.
Corrosion Resistance and Limitations
Basic Corrosion Resistance: Silicon and manganese improve atmospheric and water corrosion resistance, though base material resistance is moderate.
Protection Requirements: Galvanizing or epoxy resin coating needed for marine environments to prevent pitting risks.
Thickness Effect: Yield strength drops to ≥265 MPa for thicknesses >100 mm, requiring strength degradation checks.
