Comparison between S355J2W and S355J2WP Weathering Steel Plates (Composition & Performance):
1. Chemical Composition Differences
Phosphorus (P) Content: S355J2W ≤ 0.03%, S355J2WP 0.07–0.15% (key difference)
Copper (Cu)/Chromium (Cr)/Nickel (Ni): Same ranges (Cu 0.25–0.55%, Cr 0.40–1.25%, Ni optional)
"P" Designation: Indicates enhanced corrosion resistance in S355J2WP via controlled phosphorus addition
2. Performance Comparison
Mechanical Properties: Identical yield/tensile strength (≥355 MPa / 470–630 MPa) and toughness (-20°C ≥27J) Weather Resistance: S355J2WP offers 15–25% better corrosion resistance in coastal/industrial atmospheres
3. Application Guidance
S355J2W: Ideal for inland structures (bridges, towers)
S355J2WP: Recommended for aggressive environments (seaside facilities, chemical plants)
Note: Preheat S355J2WP (>20mm thickness to 150°C) to prevent P-induced brittleness during welding.
