S355NL Hardness and Strength

S355NL Hardness and Strength

S355NL hardness, S355NL steel hardness, and S355NL tensile strength are critical properties defining this high-strength, low-alloy structural steel under EN 10025-3, which specifies normalized or normalized rolled weldable fine grain structural steels. These properties make S355NL ideal for applications requiring robust performance in cold climates, such as offshore platforms and wind towers.

This article explores the hardness, tensile strength, chemical composition, and related mechanical properties of S355NL, addressing core keywords s355nl hardness, s355nl steel hardness, and s355nl tensile strength. For more details, visit our EN 10025-3 S355NL normalized structural steel plate.

What is S355NL Steel?

S355NL is a fine-grain structural steel under EN 10025-3, designed for high strength and low-temperature toughness. Its designation indicates:

• S: Structural steel.
• 355: Minimum yield strength of 355 MPa (≤16 mm).
• NL: Normalized or normalized rolled, with impact toughness tested at -50°C.

The S355NL hardness and S355NL tensile strength support its use in demanding structural applications.

S355NL Hardness

S355NL steel hardness is typically in the range of 150-190 HB (Brinell hardness) for normalized plates, though EN 10025-3 does not specify a direct hardness value. Hardness depends on thickness, heat treatment, and composition:

• Normalized Condition: The normalization process refines the grain structure, reducing hardness compared to quenched steels, enhancing toughness while maintaining strength.
• Measurement: Hardness is tested using Brinell (HB) or Vickers (HV) methods, with typical values around 150-170 HB for thinner plates (≤16 mm) and slightly higher (up to 190 HB) for thicker sections due to slower cooling rates.
• Application Impact: The moderate S355NL hardness ensures good machinability and wear resistance for structural components like bridge girders.

S355NL Strength Properties

The S355NL tensile strength and yield strength are key to its structural performance:

• Yield Strength: ≥355 MPa (≤16 mm) ensures resistance to deformation under heavy loads, ideal for wind towers and bridges.
• Tensile Strength: 470-630 MPa (S355NL tensile strength) provides durability against breaking forces, supporting structural integrity.
• Elongation: ≥22% allows ductility for complex designs.
• Impact Toughness: ≥27 J at -50°C ensures reliability in cold climates, complementing moderate hardness.

Chemical Composition Supporting Hardness and Strength

The S355NL steel hardness and strength are driven by its composition:

Key Elements:

• Low Carbon (C): ≤0.18% keeps S355NL hardness moderate, enhancing toughness.
• Manganese (Mn): Boosts S355NL tensile strength and yield.
• Aluminum (Al), Niobium (Nb): Refine grains, balancing hardness and toughness.
• Carbon Equivalent (CEV): ≤0.43% (≤63 mm), calculated as CEV = C + Mn/6 + (Cr + Mo + V)/5 + (Ni + Cu)/15, ensures weldability.

Welding and Heat Treatment

S355NL supports welding without compromising S355NL steel hardness:

• Welding: GMAW or SAW per EN 1011-2. Preheating (100-150°C) for >20 mm; no preheat for thinner plates.
• PWHT: Optional at 550-650°C for critical welds.
• Consumables: ER70S-6 (GMAW), EM12K flux with EH14 wire (SAW).

Moderate hardness ensures machinability and weld integrity.

Applications

The S355NL hardness and S355NL tensile strength support:

• Offshore Platforms: Resists impact in cold marine environments.
• Wind Turbine Towers: Withstands sub-zero loads.
• Bridges and Cranes: Load-bearing in northern climates.
• Pressure Vessels: Low-temperature storage systems.

Explore EN 10025-3 S420NL normalized structural steel plate.

Why Choose Gangsteel?

Gangsteel supplies S355NL:

• 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 S355NL hardness?
S355NL hardness ranges from 150-190 HB (Brinell), typically 150-170 HB for thinner plates (≤16 mm) and up to 190 HB for thicker sections, due to normalized fine-grain structure ensuring machinability and toughness.

What is the S355NL steel hardness range?
S355NL steel hardness is approximately 150-190 HB, moderate due to low carbon (≤0.18%) and normalization, balancing wear resistance and ductility for applications like bridge girders.

What is the S355NL tensile strength?
S355NL tensile strength is 470-630 MPa (≤100 mm), dropping to 450-610 MPa for thicker plates (100-250 mm), providing durability for offshore platforms and wind towers.

How does S355NL hardness affect applications?
The moderate S355NL hardness (150-190 HB) ensures good machinability and wear resistance, ideal for fabricating complex structures like cranes while maintaining -50°C toughness.

Is S355NL weldable with its hardness?
Yes, S355NL’s moderate hardness and low CEV (≤0.43%) support GMAW/SAW welding with minimal preheating (100-150°C for >20 mm), ensuring strong welds for structural applications.

How does S355NL compare to S355J2?
S355NL is normalized, tested at -50°C with similar hardness (150-190 HB) and tensile strength (470-630 MPa); S355J2 is hot-rolled, tested at -20°C, less suited for cold climates. See EN 10025-3 S355N normalized structural steel plate.