Q620FTD Wind Power Steel

Ultra-High-Strength Low-Temperature Grade – 620MPa Yield, Guaranteed -20°C Impact Toughness (47J) for Next-Generation Large Wind Towers

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

Product Overview

This article introduces Q620FTD 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. Q620FTD provides 620 MPa minimum yield, excellent toughness at -20°C (Grade D), and complies with GB/T 28410-2012 for wind tower construction.

Q620FTD is an ultra-high-strength low-alloy structural steel plate specifically designed for next-generation large wind power generation equipment requiring maximum load-bearing capacity and low-temperature toughness.

Key Advantages

  • Ultra-High Strength + Low-Temperature Toughness: Minimum yield strength of 620MPa combined with guaranteed -20°C impact toughness (47J).
  • Optimized for Large Turbines: Designed for next-generation large wind towers requiring superior load-bearing capacity.
  • Excellent Weldability: Optimized chemical composition with low carbon equivalent ensures reliable fabrication.
  • Cost-Effective Solution: Ultra-high strength enables significant weight reduction for 10MW+ turbines.

International Grade Comparison

🇨🇳 Q620FTD (GB/T 28410-2012)
C: ≤0.20%
Mn: ≤1.80%
P: ≤0.020%
S: ≤0.010%
Si: ≤0.60%
Als: ≥0.015%
Yield: ≥620MPa (≤16mm)
Impact: -20°C (47J)
🇪🇺 EN 10025-2 S690 Series
C: ≤0.20%
Mn: ≤1.80%
P: ≤0.035%
S: ≤0.035%
Si: ≤0.60%
N: ≤0.012%
Yield: ≥690MPa
Impact: J2=-20°C
Functional Equivalent: Q620FTD ≈ S690J2 (-20°C impact)
🇺🇸 ASTM A709 Gr.100 (A709Gr100)
C: ≤0.20%
Mn: ≤1.35%
P: ≤0.035%
S: ≤0.035%
Si: 0.15-0.40%
Cu: ≥0.20%
Yield: ≥690MPa (100ksi)
Tensile: ≥620MPa
Note: Q620FTD has specified -20°C impact (47J) for wind tower applications.
Note: Q620FTD is an ultra-high-strength grade. EN S690J2 offers similar -20°C impact properties. ASTM A709 Gr.100 is a bridge-grade steel with comparable strength.

Domestic Grade Comparison: Q550FTD / Q690FTD

Q550FTD
Impact: -20°C

Yield: ≥460MPa

Tensile: 670-830MPa

Impact: 34J

Q620FTD ★
Impact: -20°C

Yield: ≥620MPa

Tensile: 710-880MPa

Impact: 47J

Q690FTD
Impact: -20°C

Yield: ≥690MPa

Tensile: 770-940MPa

Impact: 47J

Note: Q620FTD offers ultra-high yield strength (620MPa) with -20°C impact toughness. Q550FTD has lower strength, and Q690FTD provides even higher strength for extreme applications.

Technical Specifications

Q620FTD Chemical Composition (GB/T 28410-2012, wt%)

Element Value / Range
C (max) 0.20
Mn (max) 1.80
P (max) 0.020
S (max) 0.010
Si (max) 0.60
Nb (max) 0.070
V (max) 0.15
Ti (max) 0.050
Mo (max) 0.50
Cr (max) 0.80
Ni (max) 0.80
Cu (max) 0.55
Als (min) 0.015
N (max) 0.012
Note: Lower limit of Mn for normalized delivery as specified. Higher alloy content for ultra-high strength.

Applications

Next-Generation Large Wind Turbine Towers (10MW+)

Primary application for Q620FTD, offering ultra-high strength (620MPa yield) and -20°C impact toughness for the next generation of large wind turbine tower structures requiring maximum load-bearing capacity and reliable low-temperature performance.

  • Tower shell sections for next-generation large wind turbines (10MW+)
  • Flanges, ring stiffeners, connection brackets for heavy-load designs
  • Transition pieces and bottom sections for tallest towers (140m+ hub height)
  • Offshore wind power projects demanding maximum strength

Available Supply Range

📏 Thickness

  • Plates: 8-120mm
  • Coils: 2.0-12.0mm

📐 Width & Length

  • Width: 900-5300mm
  • Length: 6000-12000mm
Lead Time: 40-60 days for ultra-high-strength grade

Custom Fabrication Services

Custom Cutting

Edge Beveling

Drilling & Punching

Bending & Forming

Quality & Manufacturing Assurance

ISO 9001:2015
CE Marking
SGS/BV/TÜV

Packaging & Logistics

  • Bundled with steel straps on wooden skids
  • Marking: Grade, size, heat number, weight, impact grade D (-20°C)
  • FOB/CIF/CFR from main Chinese ports

Frequently Asked Questions

Q620FTD vs Q550FTD?

Q620FTD has higher yield strength (620MPa vs 460MPa) and higher tensile strength (710-880MPa vs 670-830MPa), suitable for next-generation large turbines.

International equivalents?

Comparable to EN 10025-2 S690J2 and ASTM A709 Gr.100.

Third-party inspection?

Yes, SGS, BV, TÜV available including -20°C impact verification.

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