S355N, under EN 10025-3, is a normalized, low-alloy steel with 355 MPa yield strength and -20°C toughness, ideal for demanding structures in moderate climates. S355J2+N, under EN 10025-2, is a non-alloy, normalized steel with similar strength and toughness, suited for general construction with cost-effective processing.
As part of the en 10025 3 normalized steel plate and EN 10025-2 families, these grades serve distinct purposes.
S355N (EN 10025-3, 1.0545): A normalized or normalized rolled fine-grain steel with 355 MPa yield strength and -20°C toughness, designed for high-load applications like bridges and cranes in moderate climates.
S355J2+N (EN 10025-2): A non-alloy, normalized steel with 355 MPa yield strength and -20°C toughness, widely used for general construction due to its cost-effectiveness and versatility.
S355N offers enhanced toughness due to its fine-grain, low-alloy structure, while S355J2+N is simpler and more economical for less demanding projects.
Chemical Composition Comparison
|
Element |
S355N (EN 10025-3, Ladle, max %) |
S355J2+N (EN 10025-2, max %) |
Role in Properties |
|---|---|---|---|
|
Carbon (C) |
0.20 |
0.20 |
Similar, ensures weldability and toughness. |
|
Silicon (Si) |
0.50 |
0.55 |
S355J2+N's slightly higher Si aids deoxidation. |
|
Manganese (Mn) |
0.90-1.65 |
1.60 |
S355N's range supports fine-grain structure. |
|
Phosphorus (P) |
0.030 |
0.025 |
S355J2+N's lower P enhances toughness. |
|
Sulfur (S) |
0.025 |
0.025 |
Identical, ensures weld quality. |
|
Nitrogen (N) |
0.025 |
0.012 |
S355J2+N's lower N reduces brittleness. |
|
Aluminum (Al) |
0.020 (min, total) |
- |
S355N's Al refines grains for toughness. |
|
Niobium (Nb) |
0.05 |
- |
S355N's Nb enhances fine-grain structure. |
|
Vanadium (V) |
0.10 |
- |
S355N's V boosts strength. |
|
Chromium (Cr) |
0.30 |
0.30 |
Similar, improves corrosion resistance. |
|
Nickel (Ni) |
0.50 |
0.30 |
S355N's higher Ni improves toughness. |
|
Molybdenum (Mo) |
0.10 |
- |
S355N's Mo enhances strength. |
|
Copper (Cu) |
0.55 |
0.55 |
Similar, aids corrosion resistance. |
Carbon Equivalent (CEV):
S355N: ≤0.43% (≤63 mm).
S355J2+N: ≤0.45% (≤40 mm).
S355N's microalloying (Nb, V, Al) and higher nickel content enhance its fine-grain structure and toughness, while S355J2+N's simpler composition and lower phosphorus/nitrogen make it more cost-effective, similar to en 10025 3 s420n normalized structural steel plate.
Mechanical Properties Comparison
|
Property |
S355N (EN 10025-3, ≤16 mm) |
S355J2+N (EN 10025-2, ≤16 mm) |
|---|---|---|
|
Yield Strength (min, MPa) |
355 |
355 |
|
Tensile Strength (MPa) |
470-630 |
470-630 |
|
Elongation (min, %) |
22 |
22 |
|
Impact Toughness (min, J) |
27 @ -20°C |
27 @ -20°C |
|
Hardness (Brinell) |
150-190 (typical) |
140-180 (typical) |
Yield Strength: Both offer 355 MPa, ideal for moderate-load structures.
Tensile Strength: Identical range (470-630 MPa) ensures comparable durability.
Elongation: Both provide ≥22%, supporting complex designs.
Impact Toughness: Both offer ≥27 J at -20°C, suitable for moderate climates.
Hardness: S355N's slightly higher hardness (150-190 HB vs 140-180 HB) reflects its fine-grain structure.
Thickness: S355N up to 200 mm, S355J2+N up to 400 mm, offering greater thickness versatility for S355J2+N, similar to en 10025 3 s355n normalized structural steel plate.
Applications
S355N: Used in high-load structures like bridges, cranes, and heavy machinery in moderate climates, leveraging its fine-grain structure and enhanced toughness.
S355J2+N: Applied in general construction, buildings, and infrastructure, where cost-effectiveness and standard toughness are sufficient.
S355N is preferred for critical applications requiring superior toughness, while S355J2+N suits cost-sensitive projects. For colder climates, consider en 10025 3 s355nl normalized structural steel plate.
Key Differences Summarized
|
Feature |
S355N (EN 10025-3) |
S355J2+N (EN 10025-2) |
|---|---|---|
|
Type |
Low-alloy, normalized |
Non-alloy, normalized |
|
Composition |
Microalloyed (Nb, V, Al) |
Simpler, no microalloying |
|
CEV |
≤0.43% |
≤0.45% |
|
Toughness |
Enhanced by fine-grain structure |
Standard toughness |
|
Applications |
High-load structures (bridges, cranes) |
General construction, buildings |
|
Cost |
Higher (due to microalloying) |
Lower (simpler composition) |
