S355NL vs S355J2 Strength and Toughness

S355NL vs S355J2: Strength and Toughness

S355NL vs S355J2 represents a comparison between two widely used structural steels under the European standard EN 10025. S355NL, specified under EN 10025-3, is a normalized fine-grain steel with superior low-temperature toughness, while S355J2, under EN 10025-2, is a hot-rolled non-alloy steel for general applications.

Understanding the S355NL S355J2 difference in strength, toughness, and applications is crucial for selecting the right material. This article compares their chemical composition, mechanical properties, welding characteristics, and uses, addressing core keywords like s355nl vs s355j2, s355nl s355j2 difference, s355j2 vs s355nl, and s355nl s355j2. For more details, explore 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: Impact toughness tested at -50°C for low-temperature applications.

It excels in cold climates due to its refined microstructure.

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.

It’s cost-effective for general structural use in moderate conditions.

Chemical Composition Comparison

The S355NL S355J2 difference begins with their chemical compositions, which affect toughness and weldability.

Carbon Equivalent (CEV):

• S355NL: ≤0.43% (≤63 mm), enhanced by fine-grain elements (Al, Nb).
• S355J2: ≤0.45% (≤40 mm), slightly higher due to less stringent controls.

S355NL vs S355J2 shows S355NL’s lower impurities (e.g., sulfur, phosphorus) and grain-refining elements improve toughness and weldability.

Mechanical Properties: Strength and Toughness

The S355J2 vs S355NL comparison hinges on strength and toughness differences.

Strength: Both grades share identical yield (355 MPa) and tensile strengths (470-630 MPa) for similar thicknesses, making them equally robust for load-bearing.
Toughness: The key s355nl s355j2 difference is toughness. S355NL is tested at -50°C, ideal for arctic or offshore environments, while S355J2’s -20°C testing suits milder climates.
Thickness Range: S355NL maintains properties up to 250 mm; S355J2 up to 250 mm but with less low-temperature focus.

Welding and Heat Treatment

• S355NL: Low CEV (≤0.43%) and fine-grain structure ensure excellent weldability with GMAW or SAW. Preheating (100-150°C) for >20 mm; PWHT (550-650°C) optional. Consumables: ER70S-6 (GMAW), EM12K flux with EH14 wire (SAW).
• S355J2: CEV ≤0.45% supports welding, but higher impurities may require more preheating (>25 mm). Same consumables apply.

S355NL vs S355J2 welding shows S355NL’s finer grain reduces weld imperfections.

Applications

• S355NL: Suited for low-temperature applications:
  • Offshore platforms in cold marine environments.
  • Wind towers in sub-zero climates.
  • Bridges and cranes in northern regions.
    Its -50°C toughness ensures reliability in harsh conditions. See EN 10025-3 S355NL normalized structural steel plate.
• S355J2: Ideal for general structural use:
  • Building frameworks in temperate climates.
  • Bridges and machinery with moderate temperature demands.
  • Cost-effective welded assemblies.

The S355J2 vs S355NL application difference highlights S355NL’s superiority in cold environments and S355J2’s affordability for standard conditions.

Equivalent Grades

• S355NL: ASTM A572 Grade 65, A633 Grade E, Q345E (China).
• S355J2: ASTM A572 Grade 50, Q345B (China).

S355NL’s fine-grain structure offers better toughness than S355J2’s non-alloy composition. See 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 is the main S355NL S355J2 difference?
S355NL is normalized fine-grain steel with -50°C toughness; S355J2 is hot-rolled, tested at -20°C.

Which has better toughness in S355NL vs S355J2?
S355NL excels at -50°C, ideal for cold climates; S355J2 is limited to -20°C.

Are S355J2 vs S355NL strengths similar?
Yes, both have 355 MPa yield and 470-630 MPa tensile strength for similar thicknesses.

Which is more weldable?
S355NL’s lower CEV (≤0.43% vs ≤0.45%) offers slightly better weldability.

What are applications of S355NL vs S355J2?
S355NL: Cold-region offshore, wind towers. S355J2: General buildings, temperate bridges.

Can S355J2 replace S355NL?
Only in non-critical cold environments; S355NL is better for sub-zero conditions.

Explore related grades like EN 10025-3 S275N normalized structural steel plate.