Q690FTD Extra‑High Strength Wind Power Steel

GB/T 28410-2012 | 690MPa Grade | -20°C Impact (47J) for next‑gen heavy‑duty turbines

📏 Standard: GB/T 28410-2012
🏗️ Heavy‑duty offshore towers
❄️ -20°C Impact 47J (Grade D)
💪 Yield ≥690 MPa (≤40mm)

Product Overview

This article introduces Q690FTD 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. Q690FTD is a high‑strength low‑alloy steel plate offering minimum yield strength of 690 MPa (≤16mm), excellent toughness at -20°C (Grade D, 47J), and complies with GB/T 28410‑2012 for wind tower construction in demanding environments requiring ultra‑high load capacity.

📊 Q690FTD Approximate Grade Lookup Table

Key Advantages

  • 690MPa Extra‑High Strength: Minimum yield 690 MPa (≤40mm) for next‑generation large wind turbines and heavy‑load tower designs, enabling significant weight reduction.
  • Enhanced -20°C Impact Toughness: Minimum 47J at -20°C (Grade D) – superior reliability for cold climate zones and offshore platforms.
  • Optimized Alloy Design: Controlled micro‑alloying (Nb, V, Ti) plus Mo, Cr, Ni for excellent strength, hardenability and weldability.
  • Low Impurity Content: P≤0.020, S≤0.010 for improved low‑temperature performance and cleanliness.
  • Weldable Fine‑Grain Steel: Low carbon equivalent design suitable for field welding of heavy tower sections.

Technical Specifications

Q690FTD Chemical Composition (GB/T 28410-2012, mass fraction %)

Element Q690FT D (max or range)
Grade Q690FT D
C (max) 0.20
Mn ≤1.80 (lower limit for normalized*)
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) 0.050
Cr (max) 0.80
Ni (max) 0.80
Cu (max) 0.80
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. No lower limit required for other conditions.

Quality & Manufacturing Assurance

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Modern Production

Advanced continuous casting and controlled rolling for extra‑high strength

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In-process Inspection

Spectral analysis, UT testing, -20°C impact verification

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Full Documentation

MTC EN 10204 3.1/3.2 with 690MPa grade results

ISO 9001:2015 CE Marking (PED) SGS Inspection Mill Certificate 3.1

Packaging & Logistics

  • Standard Packaging: Steel plates bundled with steel straps on wooden skids. Coils wrapped with waterproof paper.
  • Marking: Grade, size, heat number, weight clearly marked.
  • Logistics: FOB, CIF, CFR from main Chinese ports.
  • Lead Time: 30-40 days after order confirmation (depending on QT requirement).

Request a Quotation

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Frequently Asked Questions

What is the advantage of Q690FTD over Q620FTD?

Q690FTD provides higher strength (690 MPa yield vs 620 MPa) while maintaining similar -20°C impact toughness (47J), allowing for lighter tower sections or higher load capacity in the same thickness.

Is Q690FTD suitable for offshore wind?

Yes, its high strength and -20°C impact toughness meet requirements for many offshore wind projects in temperate and cold seas. For arctic offshore, consider Q690FTE (-40°C).

What is the typical delivery condition for Q690FTD?

It is commonly delivered in Quenched + Tempered (QT) or TMCP to achieve the 690MPa yield strength and 47J impact energy at -20°C.

Third-party inspection available?

SGS, BV, TÜV inspection can be arranged at extra cost; mill certificate EN 10204 3.1 is always included with full test results.

For immediate inquiries, contact via WhatsApp. For detailed specs, visit the product page.
✅ Q690FTD (Grade D, -20°C impact, 47J) · Yield 690/690/670 MPa · GB/T 28410-2012 · Mill certificate included