Q345FTD Wind Power Steel

High-Strength Low-Temperature Grade – 345MPa Yield, Guaranteed -20°C Impact Toughness (47J) for Cold Climate Wind Towers

📏 Standard: GB/T 28410-2012
🏗️ Cold Climate Large Wind Towers
❄️ Impact -20°C / 47J

Product Overview

This article introduces Q345FTD structural steel for wind turbine towers manufactured by Chinese steel mills, hoping to meet your needs and encourage you to purchase this grade of steel. Q345FTD provides 345 MPa minimum yield, excellent toughness at -20°C (Grade D), and complies with GB/T 28410-2012 for wind tower construction in colder environments.

Q345FTD is a high-strength structural steel plate specifically designed for wind power generation equipment requiring higher load-bearing capacity and low-temperature toughness, complying with the Chinese standard GB/T 28410-2012 (Wind turbine tower steel plate).

Key Advantages

  • Higher Strength + Low-Temperature Toughness: Minimum yield strength of 345MPa combined with guaranteed -20°C impact toughness (47J).
  • Optimized for Cold Climates: Designed for wind towers operating in winter-cold regions where low-temperature performance is critical.
  • Excellent Weldability: Optimized chemical composition with low carbon equivalent ensures ease of fabrication even in cold environments.
  • Cost-Effective Solution: Higher strength allows for lighter tower designs, reducing material and transportation costs.

International Grade Comparison

🇨🇳 Q345FTD (GB/T 28410-2012)
C: ≤0.20%
Mn: 0.90-1.65%
P: ≤0.025%
S: ≤0.015%
Si: ≤0.50%
Als: ≥0.015%
Yield: ≥345MPa (≤16mm)
Impact: -20°C (47J)
🇪🇺 EN 10025-2 S355 Series
C: ≤0.22%
Mn: ≤1.60%
P: ≤0.035%
S: ≤0.035%
Si: ≤0.55%
N: ≤0.012%
Yield: ≥355MPa
Impact: JR=20°C / J0=0°C / J2=-20°C
Functional Equivalent: Q345FTD ≈ S355J2 (-20°C impact)
🇺🇸 ASTM A709 Gr.50 (A709Gr50)
C: ≤0.23%
Mn: 0.60-1.35%
P: ≤0.035%
S: ≤0.035%
Si: 0.15-0.40%
Cu: ≥0.20%
Yield: ≥345MPa (50ksi)
Tensile: ≥450MPa
Note: Q345FTD has specified -20°C impact (47J) for cold climate wind tower applications.
Note: Q345FTD combines higher strength with -20°C impact toughness. EN S355J2 offers similar -20°C impact properties. ASTM A709 Gr.50 is a bridge-grade steel with comparable strength but typically lower guaranteed impact values.

Domestic Grade Comparison: Q275FTD / Q345FTC / Q420FTD

Q275FTD
Impact: -20°C

Yield: ≥275MPa

Tensile: 410-560MPa

Impact Energy: 47J

Q345FTC
Impact: 0°C

Yield: ≥345MPa

Tensile: 470-630MPa

Impact Energy: 47J

Q345FTD ★
Impact: -20°C

Yield: ≥345MPa

Tensile: 470-630MPa

Impact Energy: 47J

Q420FTD
Impact: -20°C

Yield: ≥420MPa

Tensile: 520-680MPa

Impact Energy: 47J

Note: Q345FTD offers higher yield strength (345MPa) than Q275FTD while maintaining -20°C impact toughness. Q345FTC has the same strength but only 0°C impact. Q420FTD provides even higher strength (420MPa) with -20°C impact for very large turbines in cold regions.

Technical Specifications

Q345FTD Chemical Composition (GB/T 28410-2012, wt%)

Element / Parameter Grade: Q345FT Class: D
C (max) 0.20
Mn 0.90~1.65
P (max) 0.025
S (max) 0.015
Si (max) 0.50
Nb (max) 0.060
V (max) 0.12
Ti (max) 0.050
Mo (max) 0.20
Cr (max) 0.30
Ni (max) 0.50
Cu (max) 0.30
Als (min) 0.015
N (max) 0.012
Note: The lower limit of Mn content for steel plates delivered in normalized condition shall be as specified in the table.

Applications

Cold Climate Large Wind Turbine Towers

Primary application for Q345FTD, offering high strength (345MPa yield) and -20°C impact toughness for large wind turbine tower structures in cold climate regions requiring superior load-bearing capacity and low-temperature reliability.

  • Tower shell sections for onshore/offshore wind turbines in cold climate zones
  • Flanges, ring stiffeners, connection brackets requiring -20°C impact toughness
  • Internal platforms, ladder supports, door frames in low-temperature service
  • Transition pieces and bottom sections for wind towers in regions with subzero conditions

Available Supply Range

📏 Thickness Range

  • Plates: 8mm - 150mm
  • Coils: 2.0mm - 12.0mm
  • Custom thickness available

📐 Width & Length

  • Width: 900mm - 5300mm
  • Length: 6000mm - 12000mm
  • Cut-to-length service
Stock availability: Regular sizes in stock for quick delivery | Mill order: Custom sizes available with 30-45 days lead time

Custom Fabrication Services

Custom Cutting

Laser/Plasma cutting

Edge Beveling

Single/double bevel

Quality & Manufacturing Assurance

ISO 9001:2015
CE Marking
SGS/BV/TÜV

Packaging & Logistics

  • Standard Packaging: Steel plates bundled with steel straps on wooden skids.
  • Marking: Grade, size, heat number, weight, impact grade D (-20°C).
  • Lead Time: Typically 30-45 days after order confirmation.

Frequently Asked Questions

What is the difference between Q345FTD and Q345FTC?

Q345FTD has guaranteed impact toughness at -20°C (47J), while Q345FTC is tested at 0°C (47J). Q345FTD is designed for cold climate wind power applications requiring low-temperature performance.

What are the international equivalents of Q345FTD?

Q345FTD is comparable to EN 10025-2 S355J2 (-20°C impact) and ASTM A709 Gr.50 with enhanced low-temperature requirements.

Do you offer third-party inspection?

Yes, SGS, BV, TÜV available for pre-shipment inspection and low-temperature impact testing verification.

Request a Quotation

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