Nucor Corporation has achieved a significant milestone with the granting of a patent (Publication Number: US11965230B2) for an ultra-high strength steel sheet tailored for stamping and forming processes. This innovative steel sheet is characterized by a complex metallographic structure achieved through hot rolling, incorporating precise compositions of carbon (0.02% to 0.2%), manganese (1.0% to 3.5%), and other elements within defined weight ranges.
The patented steel sheet features a multi-phase microstructure essential for its mechanical properties, including bainite, martensite+austenite (M+A) constituents, tempered and non-tempered martensite, and ferrite, each in specific volume percentages. Additionally, elements like molybdenum, chromium, nickel, titanium, or niobium may be included to further enhance the material's strength and performance, along with precipitates such as TiC, NbC, TiN, or NbN.
The ultra-high strength steel sheet exhibits impressive physical properties, surpassing 1000 megapascals in tensile strength, elongation exceeding 10% according to ASTM E8 standards, and a yield strength-to-tensile strength ratio exceeding 65%. These characteristics are crucial for demanding industrial applications where durability, formability, and performance under stress are paramount.
The microstructural complexity of the steel sheet, with its tailored phase distributions and absence of intentional boron additions, underscores its suitability for a wide range of manufacturing processes. The absence of boron enhances weldability and maintains structural integrity, addressing common challenges faced with boron-added steels.
Nucor's patent covers various configurations of composition, microstructure, and mechanical properties to meet stringent performance standards across diverse industrial applications. From automotive manufacturing to construction and beyond, this ultra-high strength steel sheet sets new benchmarks in material innovation, offering enhanced solutions for lightweight structures and components that demand both strength and flexibility.
Industry stakeholders and experts anticipate significant advancements in manufacturing efficiency and product reliability with the adoption of Nucor's patented steel sheet. As industries continue to evolve towards sustainable and high-performance materials, innovations like these are poised to drive future advancements in industrial applications globally.
