EN10025-5 S355J2WP
S355J2WP is a weathering steel grade delivered under EN 10025-5, the European standard for hot-rolled products of structural steels with improved atmospheric corrosion resistance. The designation means: S for structural steel, 355 for a minimum yield strength of 355 MPa, J2 for Charpy impact testing at -20 degrees Celsius, W for weathering steel, and P for the higher phosphorus content that promotes the protective rust layer. The grade is intended for outdoor structures where the self-protecting patina eliminates the need for painting.
Chemical Composition
The composition of S355J2WP includes carbon up to 0.12 percent, silicon up to 0.75 percent, manganese up to 1.0 percent, phosphorus in the range 0.06-0.15 percent, sulfur up to 0.030 percent, chromium 0.30-1.25 percent, and copper 0.25-0.55 percent. The elevated phosphorus, together with chromium and copper, accelerates the formation of a dense, adherent rust layer that shields the steel from further atmospheric corrosion.
Mechanical Properties
S355J2WP is specified with a tensile strength of at least 510 MPa, a minimum yield strength of 355 MPa, and a minimum elongation of 16 percent measured on a 50 mm gauge. In accordance with the J2 designation, the grade is impact tested at -20 degrees Celsius, which qualifies it for load-bearing outdoor structures in moderate cold climates.
Applications
As a weathering structural steel, S355J2WP is suited to architectural cladding, bridges, rail vehicles, containers, and other outdoor structures where the self-protecting rust patina reduces maintenance. Some commercial listings also connect the grade with pressure vessel and boiler applications; this classification is inconsistent with the grade's designation as a weathering structural steel under EN 10025-5 and should be verified against the governing pressure equipment standards before any such use is considered.
Processing and Testing
S355J2WP plates can be supplied with ultrasonic examination, as-rolled, thermo-mechanically controlled processed, normalized, or quenched and tempered delivery states, Z-direction testing, Charpy V-notch impact testing, and third-party testing, with coated or shot-blasted and painted surfaces. Packaging is standard export seaworthy packing or as required.
Frequently Asked Questions
What does S355J2WP stand for?? S means structural steel, 355 is the minimum yield strength in MPa, J2 means Charpy impact testing at -20 degrees Celsius, W means weathering steel, and P indicates higher phosphorus for weathering performance.
What are the mechanical properties of S355J2WP?? Tensile strength of at least 510 MPa, minimum yield strength of 355 MPa, minimum elongation of 16 percent measured on a 50 mm gauge, and impact testing at -20 degrees Celsius.
How does the composition support weathering behavior?? Carbon is limited to 0.12 percent, phosphorus is in the range 0.06-0.15 percent, chromium 0.30-1.25 percent, and copper 0.25-0.55 percent. The elevated phosphorus, together with chromium and copper, accelerates formation of the dense, adherent rust layer.
Is S355J2WP a pressure vessel steel?? No. S355J2WP is a weathering structural steel per EN 10025-5. Any pressure vessel or boiler use would require verification against the relevant pressure equipment standards before such service is considered.
Where is S355J2WP used?? rchitectural cladding, bridges, rail vehicles, containers, and other outdoor structures where the self-protecting patina reduces maintenance.
What is the difference between S355J0WP and S355J2WP?? Both carry the higher-phosphorus P designation, but J0 is impact tested at 0 degrees Celsius while J2 is tested at -20 degrees Celsius. S355J2WP is therefore qualified for load-bearing outdoor structures in moderate cold climates.
