Q345FTF Wind Power Steel

Ultimate Polar Grade – 345MPa Yield, Guaranteed -50°C Impact Toughness (34J) for Arctic & Antarctic Wind Farms

📏 Standard: GB/T 28410-2012
🏗️ Polar / Antarctic Wind Towers
❄️ Impact -50°C / 34J

Product Overview

This article introduces Q345FTF 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. Q345FTF provides 345 MPa minimum yield, the highest low-temperature toughness at -50°C (Grade F) with 34J guaranteed impact energy, and complies with GB/T 28410-2012 for wind tower construction in extreme arctic environments.

Q345FTF (Grade F) represents the highest low-temperature toughness grade in the GB/T 28410-2012 standard, designed for polar and extreme cold climate wind power applications where temperatures can drop below -50°C.

Key Advantages

  • Ultimate Low-Temperature Toughness: Guaranteed impact toughness at -50°C (34J) – the highest cold-resistance grade available for wind tower steel.
  • High Strength + Polar Durability: 345MPa minimum yield strength combined with exceptional performance in polar environments.
  • Excellent Weldability: Optimized chemical composition with low carbon equivalent and tighter P/S control ensures reliable fabrication.
  • Cost-Effective Polar Solution: Higher strength allows for optimized tower designs in extreme environments, reducing overall project costs.

International Grade Comparison

🇨🇳 Q345FTF (GB/T 28410-2012)
C: ≤0.20%
Mn: 0.90-1.65%
P: ≤0.020%
S: ≤0.010%
Si: ≤0.50%
Als: ≥0.015%
Yield: ≥345MPa (≤16mm)
Impact: -50°C (34J)
🇪🇺 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
Comparison Note: EN S355 series typically only guarantees to -20°C. Q345FTF's -50°C requirement far exceeds standard specifications.
🇺🇸 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: A709 Gr.50 is not rated for -50°C. Q345FTF is a specialized ultimate low-temperature steel.
Note: Q345FTF is a specialized ultimate low-temperature steel. Standard international specifications like EN 10025-2 S355 and ASTM A709 do not certify impact properties at -50°C. Q345FTF is designed specifically for polar wind power applications.

Domestic Grade Comparison: Q275FTF / Q345FTE / Q420FTF

Q275FTF
Impact: -50°C

Yield: ≥275MPa

Tensile: 410-560MPa

Impact Energy: 34J

Q345FTE
Impact: -40°C

Yield: ≥345MPa

Tensile: 470-630MPa

Impact Energy: 34J

Q345FTF ★
Impact: -50°C

Yield: ≥345MPa

Tensile: 470-630MPa

Impact Energy: 34J

Q420FTF
Impact: -50°C

Yield: ≥420MPa

Tensile: 520-680MPa

Impact Energy: 34J

Note: Q345FTF is the ultimate polar grade (F = -50°C impact). Q345FTE offers -40°C with same strength. Q275FTF provides lower strength with -50°C impact. Q420FTF gives even higher strength (420MPa) with -50°C impact for the most demanding polar applications.

Technical Specifications

Q345FTF Chemical Composition (GB/T 28410-2012, wt%)

Element / Parameter Grade: Q345FT Class: F
C (max) 0.20
Mn 0.90~1.65
P (max) 0.020
S (max) 0.010
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) 0.010
Note: Tighter P/S control (P≤0.020%, S≤0.010%) and lower N content for enhanced low-temperature toughness at -50°C.

Applications

Polar & Antarctic Large Wind Turbine Towers

Primary application for Q345FTF, offering high strength (345MPa yield) and ultimate -50°C impact toughness for wind turbine tower structures in arctic, Antarctic, Siberian, and other polar regions requiring ultimate cold resistance and superior load-bearing capacity.

  • Tower shell sections for arctic, Antarctic, and Siberian wind farms
  • Flanges, ring stiffeners, connection brackets requiring -50°C impact certification
  • Offshore wind towers in polar environments and ice-resistant structures
  • Critical load-bearing components for extremely low-temperature service
  • Polar research station wind power installations

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: Made-to-order for polar grades | Mill order: Custom sizes available with 35-50 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 F (-50°C).
  • Lead Time: Typically 35-50 days after order confirmation for polar-grade steel.

Frequently Asked Questions

What is the difference between Q345FTF and Q345FTE?

Q345FTF has guaranteed impact toughness at -50°C (34J), while Q345FTE is tested at -40°C (34J). Q345FTF is the ultimate polar grade designed for arctic, Antarctic, and extreme cold climate wind power applications.

What are the international equivalents of Q345FTF?

Standard EN 10025-2 S355 series typically only guarantees down to -20°C (S355J2). ASTM A709 Gr.50 is not rated for -50°C. Q345FTF is a specialized ultimate low-temperature steel with no direct equivalent in common standards.

Do you offer third-party inspection for -50°C impact testing?

Yes, SGS, BV, TÜV available for pre-shipment inspection including low-temperature impact verification at -50°C.

Request a Quotation

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