High strength steel product and method of manufacturing the same

US12024753B2 · kind B2 · utility

Assignee

• SSAB TECHNOLOGY AB · SE

Inventors

• Vili Kesti · Raahe, FI
• Ari Hirvi · Raahe, FI
• Tommi Liimatainen · Raahe, FI
• Mikko Hemmilä · Helsinki, FI
• Pasi Suikkanen · Raahe, FI
• Erik Nymann · Nordstraße, SE
• Martin Lind · Munich, DE
• Robin Nilsson · Nordstraße, SE
• Juha Pyykkönen · Raahe, FI

Key dates

• Filing date: May 20, 2021
• Grant date: Jul 2, 2024
• Expiry date: May 20, 2041

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/26
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A hot-rolled strip steel product is described having a chemical composition consisting of, in terms of weight percentages (wt. %): 0.030%-0.10% C, 0%-1.10% Si, 0.50%-2.0% Mn, <0.020% P, <0.010% S, <0.010% N, 0%-0.60% Cr, 0%-0.20% Ni, 0%-0.25% Cu, 0%-0.30% Mo, 0%-0.15% Al, 0%-0.10% Nb, 0.10%-0.30% V, <0.020% Ti, 0%-0.0010% B, remainder being Fe and inevitable impurities, wherein the hot rolled strip steel product has a a microstructure comprising, in terms of volume percentages (vol. %), ferrite≥90, wherein the ferrite structure comprises bainite, at least 50% of polygonal ferrite and at most 10% quasi-polygonal ferrite, and wherein the steel strip product has an average hole expansion ratio≥50%, a yield strength (Rp0.2%) longitudinal to rolling direction of ≥660 MPa and a tensile strength≥760 MPa.