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Elcyon™ is the world’s most sustainable steel plate conforming to EuroNorm 10025 and 10225, available in the full range of sizes and piece weights required for offshore wind projects.



  1. Optimized for Offshore

    Elcyon’s low carbon, low alloy chemistry and thermo-mechanically controlled processing (TMCP) yield the strength and toughness required for the most demanding offshore wind applications.
  1. Sustainable

    Elcyon is the world’s first steel plate for offshore wind applications made using electric arc furnace (EAF) technology, with a recycled content in excess of 90% and greenhouse gas emissions 1/5 the global blast furnace average.
  1. Manufactured in the USA

    Elcyon is the only plate steel in offshore wind sizes that is melted and manufactured in the USA, offering energy stakeholders efficient, reliable access and accelerated delivery timelines.
  1. Nationwide Delivery

    Elcyon can be delivered to any project or fabrication site in the USA via rail or barge.

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Nucor created Elcyon to meet the rigorous standards of offshore wind energy designers, manufacturers, and fabricators, while also meeting Nucor’s rigorous standards for performance and sustainability.


Elcyon's low carbon equivalency chemistry offers superior processing for the high heat inputs of offshore fabrication.


The clean, consistent microstructure of Elcyon offers predictable, repeatable shop fabrication

High Fracture Toughness

Designed with demanding offshore applications in mind, Elcyon foundations offer superior performance in hostile applications

Elcyon Specifications At A Glance

Nucor is the only domestic supplier of sustainable steel plate meeting the requirements of EuroNorm 10025 and 10225 in a full range of sizes and piece weights required for offshore wind fabrication.

Elcyon is available nationwide and can be delivered to any project or fabrication site in the USA via rail or barge.

Comparison of Elcyon to A572-50
Measure Elcyon S355 ML Elcyon S420 ML A572-50
Min. Yield strength 335 Mpa / 48 ksi 390 Mpa / 56 ksi 345 Mpa / 50 ksi
Min. Tensile strength 470 Mpa / 65 ksi 500 Mpa / 72 ksi 450 Mpa / 65 ksi
Max yield-to-tensile ratio 0.84 0.84 0.87
Min. elongation (8” sample) 22% 19% 16%
Min. L-CVN @-40° C (-40° F) 31J, 23 ft-lbs 31J, 23 ft-lbs --
Typical carbon equivalent, % 0.41 0.44 0.46

*Properties shown are typical for a 76mm (3") gauge plate


Learn More

View the Elcyon brochure

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  1. Which thickness range, dimensions and piece weights will apply to Elcyon™?

    Elcyon will be available in Nucor Steel Brandenburg’s full and unmatched capability range. Learn more here. Elcyon will be available up to 4.3 m (170”) wide and in piece weights up to 45 MT (100,000#). This wide dimensional range in combination with heavy piece weights satisfies the current designs and specifications of the Offshore Wind developers to build the foundations that are needed to make “30GW by 2030” a reality in the US. Nucor will have enough plate- and other steel product capacity to meet the projected domestic steel demand while providing excellent value to the global Offshore Wind Sector. 
  2. When will Elcyon be available?

    Nucor is developing the Elcyon product now and anticipates commercial release by year end 2023 after the approval- and certification process for the Offshore-Wind-plate-specifications has been completed.
  3. How will Elcyon be shipped?

    Ideally located in the central United States on the Ohio River, Nucor Steel Brandenburg has an extensive transportation network encompassing truck, rail, and barge modes. Reach out to our commercial team here to learn more. Nucor is in a position to deliver Elcyon in all of its dimensional range to any project location, both domestically and internationally.
  4. Will there be a price premium and will/can Elcyon be tied to any steel-index?

    Given the uniqueness of its properties, its wide dimensional range, and the heavy piece weights, Elcyon will not be priced publicly and by inquiry only. For any commercial interest please reach out to Markus Mueller, Manager Wind Energy Solutions.
  5. Can Elcyon be certified as Econiq? Explain more about net-zero steel and the sustainability aspects of Elcyon.

    Nucor produces steel by melting scrap in electric arc furnaces (EAF). All Nucor products are capable of being certified as Econiq™. Further, Nucor Steel Brandenburg will be the first steelmaking facility in the world to be LEEDV4 certified. Combined with a renewable application, Elcyon’s sustainability story is unmatched! Learn more about Econiq and Nucor’s sustainability story here.
  6. What is TMCP? Please explain so that a non-metallurgist can understand. Is this a technique that just Nucor can do? Who are your competitors on TMCP? Does plate for offshore wind have to be produced in TMCP-condition?

    TMCP is Thermo-Mechanically Controlled Processing. TCMP is an advanced combination of steelmaking technology, temperature-controlled rolling and accelerated cooling to achieve high strength and toughness steels with a low carbon equivalent for ease of forming and welding. Elcyon has a superb microstructure and physical characteristics. While other mills can produce TMCP-steel, NSBB is the only mill in the US capable of producing the required offshore wind specification S355ML-TMCP at scale in all of its dimensions and piece weights.
  7. How is Elcyon pronounced?

    The name Elcyon is pronounced "el • see • uhn"

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