S355NL vs S355J2: Weldability
S355NL vs S355J2 weldability is a critical factor when choosing between these structural steels under the EN 10025 standard. S355NL, specified under EN 10025-3, is a normalized fine-grain steel optimized for low-temperature toughness, while S355J2, under EN 10025-2, is a hot-rolled non-alloy steel for general applications. The difference between S355J2 and S355NL in weldability stems from their chemical compositions and processing, impacting fabrication ease and performance in welded structures.
This article compares their weldability, chemical composition, mechanical properties, and applications, addressing core keywords s355nl vs s355j2 and difference between s355j2 and s355nl. For more details, visit our EN 10025-3 S355NL normalized structural steel plate.
Overview of S355NL and S355J2
S355NL (EN 10025-3)
S355NL is a fine-grain structural steel, normalized or normalized rolled, with:
S: Structural steel.
355: Minimum yield strength of 355 MPa (≤16 mm).
NL: Normalized, with impact toughness tested at -50°C.
Its fine-grain structure enhances weldability and toughness in cold climates.
S355J2 (EN 10025-2)
S355J2 is a non-alloy structural steel, typically hot-rolled, with:
S: Structural steel.
355: Minimum yield strength of 355 MPa (≤16 mm).
J2: Impact toughness tested at -20°C.
S355J2 is cost-effective for general construction in temperate climates.
Weldability Comparison
The difference between S355J2 and S355NL in weldability is driven by their chemical composition and processing:
S355NL:
Carbon Equivalent (CEV): ≤0.43% (≤63 mm), calculated as CEV = C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15.
Welding: Supports GMAW (Gas Metal Arc Welding) and SAW (Submerged Arc Welding) per EN 1011-2. Preheating (100-150°C) is recommended for thicknesses >20 mm to prevent hydrogen-induced cracking; no preheat is needed for thinner plates.
Consumables: ER70S-6 (GMAW), EM12K flux with EH14 wire (SAW).
Advantages: Lower carbon (≤0.18%), sulfur (≤0.015%), and phosphorus (≤0.025%), combined with grain-refining elements (Al, Nb), reduce weld imperfections and enhance toughness in welded joints, especially in cold conditions.
Post-Weld Heat Treatment (PWHT): Optional at 550-650°C for critical welds, rarely required due to low CEV.
S355J2:
CEV: ≤0.45% (≤40 mm), slightly higher due to less stringent impurity controls.
Welding: Compatible with GMAW and SAW, but requires more preheating (125-175°C for >25 mm) due to higher carbon (≤0.20%) and impurities (P, S ≤0.025%).
Consumables: Same as S355NL (ER70S-6, EM12K flux).
Challenges: Higher carbon and impurities increase the risk of weld imperfections like cracking, requiring more careful welding procedures.
PWHT: Rarely needed, but may be applied for thick sections to reduce stresses.
Key Weldability Difference: S355NL offers superior weldability due to its lower CEV (≤0.43% vs ≤0.45%) and fine-grain structure, reducing preheating needs and weld imperfections compared to S355J2. This makes S355NL vs S355J2 welding more cost-effective and reliable for cold-climate applications.
Chemical Composition Comparison
The S355NL vs S355J2 weldability is influenced by their compositions:
|
Element |
S355NL (EN 10025-3, Ladle, max %) |
S355J2 (EN 10025-2, max %) |
|---|---|---|
|
Carbon (C) |
0.18 |
0.20 |
|
Silicon (Si) |
0.50 |
0.55 |
|
Manganese (Mn) |
0.90-1.65 |
1.60 |
|
Phosphorus (P) |
0.025 |
0.025 |
|
Sulfur (S) |
0.015 |
0.025 |
|
Nitrogen (N) |
0.015 |
Not specified |
|
Aluminum (Al) |
0.02 (min, total) |
Not specified |
|
Niobium (Nb) |
0.05 |
Not specified |
|
Vanadium (V) |
0.12 |
Not specified |
|
Titanium (Ti) |
0.05 |
Not specified |
|
Chromium (Cr) |
0.30 |
0.30 |
|
Nickel (Ni) |
0.30 |
0.30 |
|
Copper (Cu) |
0.55 |
0.55 |
FAQ:
Q:Are you a factory or a trading company?
A:We are a professional manufacture and have many years production and management experience.
Q:What are the shipping terms?
A:We accept FOB,CIF,CFR and other international shipping terms.Port of loading can be specified according to customer requirements.
Q:Do you have after-sales service?
A:Of course, you can contact us at any time.we promise our products are all qualified. If you find any products are not qualified and unsatisfied your require,please contact us at any time.
Hot Tags: en s355nl vs s355j2 structure steel plate, China en s355nl vs s355j2 structure steel plate manufacturers, suppliers, factory, high strength steel plate quality standard, high strength steel plate shearing, hsla steel sheet certification, low alloy steel sheet availability, low alloy steel sheet cut to size, low alloy steel sheet manufacturer
