S355NL vs S355JR Key Properties

S355NL vs S355JR: Key Properties

S355NL vs S355JR is a critical comparison for structural engineers selecting steels under the EN 10025 standard. S355NL, specified under EN 10025-3, is a normalized fine-grain steel optimized for low-temperature toughness, while S355JR, under EN 10025-2, is a hot-rolled non-alloy steel for general use. The S355JR vs S355NL comparison highlights differences in toughness, weldability, and processing, impacting their suitability for various applications. This article compares their key properties, including chemical composition, mechanical properties, weldability, and applications, addressing core keywords s355nl vs s355jr and s355jr vs s355nl. For more details, visit our EN 10025-3 S355NL normalized structural steel plate.

Overview of S355NL and S355JR

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 for low-temperature performance.

It’s ideal for cold climates, such as offshore platforms and arctic bridges.

S355JR (EN 10025-2)

S355JR is a non-alloy structural steel, typically hot-rolled, with:

• S: Structural steel.
• 355: Minimum yield strength of 355 MPa (≤16 mm).
• JR: Impact toughness tested at +20°C (or not tested, depending on specification).

S355JR is cost-effective for general construction in temperate climates.

Key Properties Comparison

Chemical Composition

The S355NL vs S355JR comparison reveals differences in composition affecting toughness and weldability:

Carbon Equivalent (CEV):

• S355NL: ≤0.43% (≤63 mm).
• S355JR: ≤0.45% (≤40 mm).

Key Difference: S355NL’s lower carbon (0.18% vs 0.24%), sulfur (0.015% vs 0.035%), and phosphorus (0.025% vs 0.035%), plus grain-refining elements (Al, Nb, V), enhance toughness and weldability compared to S355JR.

Mechanical Properties

The S355JR vs S355NL mechanical properties differ primarily in toughness:

• Strength: Both grades share identical yield (355 MPa) and tensile strengths (470-630 MPa) for similar thicknesses, ensuring comparable load-bearing capacity.
• Toughness: S355NL’s -50°C impact testing (≥27 J) makes it ideal for sub-zero climates, while S355JR’s +20°C testing (or none) limits it to milder conditions.
• Hardness: S355NL has slightly higher hardness (150-190 HB) due to normalization, compared to S355JR (130-170 HB), but both are machinable.
• Thickness Range: Both support up to 250 mm, but S355NL’s fine-grain structure enhances cold performance.

Weldability

• S355NL: CEV ≤0.43% supports GMAW or SAW (EN 1011-2). Preheating (100-150°C) for >20 mm; PWHT optional (550-650°C). Consumables: ER70S-6 (GMAW), EM12K flux with EH14 wire (SAW). Lower impurities reduce weld imperfections.
• S355JR: CEV ≤0.45% requires more preheating (125-175°C for >25 mm) due to higher carbon and impurities. Same consumables. Higher CEV increases cracking risk.

Key Difference: S355NL’s lower CEV and fine-grain structure make it more weldable, especially in cold conditions.

Applications

• S355NL:
  • Offshore platforms in cold marine environments (e.g., Arctic seas).
  • Wind towers in sub-zero climates (e.g., northern Europe).
  • Bridges and cranes in arctic regions.
    Its -50°C toughness and weldability ensure reliability in extreme cold. See EN 10025-3 S355NL normalized structural steel plate.
• S355JR:
  • Building frameworks in temperate climates.
  • Bridges and machinery in moderate conditions.
  • General fabrication where cost is a priority.

The S355NL vs S355JR application difference highlights S355NL’s superiority in cold environments and S355JR’s affordability for standard conditions.

Which is Better: S355NL or S355JR?

• Choose S355NLfor:
  • Cold climates requiring -50°C toughness (e.g., arctic offshore platforms).
  • Applications needing superior weldability and toughness.
  • Thicker sections with consistent low-temperature performance.
• Choose S355JRfor:
  • Temperate climates where +20°C toughness (or none) is sufficient.
  • Cost-sensitive projects with standard structural requirements.
  • General fabrication with less extreme conditions.

The S355JR vs S355NL choice depends on environmental conditions and budget.

Equivalent Grades

• S355NL: ASTM A633 Grade E, Q345E (China), TStE 355 (DIN).
• S355JR: ASTM A572 Grade 50, Q345B (China), SM490A (JIS).

Explore EN 10025-3 S420NL normalized structural steel plate.

Why Choose Gangsteel?

Gangsteel supplies both grades:

• Inventory: Extensive stock in China.
• Sizes: Thickness 6–250 mm, widths 2000/2500/3000 mm, lengths up to 12,000 mm.
• Delivery: 7-30 days globally.
• Certifications: EN 10204 3.1/3.2, UT testing (EN 10160), ABS/LR/BV/DNV approvals.
• Processing: Cutting, welding, bending.

Contact us for EN 10025-3 S355NL normalized structural steel plate.

FAQ

What are the key property differences in S355NL vs S355JR?
S355NL is normalized, tested at -50°C (≥27 J) for cold climates, with better weldability (CEV ≤0.43%); S355JR is hot-rolled, tested at +20°C (if tested), with CEV ≤0.45%, suited for temperate regions. Both have 355 MPa yield.

How does toughness differ in S355JR vs S355NL?
S355NL offers -50°C toughness (≥27 J), ideal for arctic applications; S355JR’s +20°C toughness (if tested) limits it to milder climates, lacking guaranteed cold performance.

Which is better for cold climates in S355NL vs S355JR?
S355NL is superior for cold climates due to its -50°C impact toughness, ensuring safety in arctic offshore platforms and bridges, unlike S355JR’s +20°C limit.

How does weldability compare in S355JR vs S355NL?
S355NL (CEV ≤0.43%) requires less preheating (100-150°C vs 125-175°C for >20 mm) than S355JR (CEV ≤0.45%), reducing weld imperfections and fabrication costs.

What are applications of S355NL vs S355JR?
S355NL is used in cold-climate offshore platforms, wind towers, and bridges; S355JR suits temperate building frameworks and general fabrication where cost is key.

Can S355JR replace S355NL?
S355JR can replace S355NL in temperate climates with careful welding, but not in sub-zero conditions due to inferior toughness.