Cold-rolled steel sheet and method for manufacturing same
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- POHANG IRON & STEEL CO LTD
- Filing Date
- 2025-12-16
- Publication Date
- 2026-06-25
AI Technical Summary
Existing cold-rolled steel sheets with ultra-high tensile strength of 1470 MPa or higher face challenges in achieving both high strength and impact characteristics, as martensitic structures exhibit low impact energy and a high risk of brittle fracture.
A cold-rolled steel sheet composition and manufacturing process that includes specific alloying elements and controlled microstructures, such as a core with a high dislocation density and a surface layer with defined properties, along with a multi-step cooling and annealing process to achieve a balanced microstructure of fresh and tempered martensite, ensuring high strength and improved impact characteristics.
The solution results in a cold-rolled steel sheet with a tensile strength of 1470 MPa or higher, exhibiting excellent impact absorption energy, bending properties, and resistance to hydrogen embrittlement, while maintaining adequate elongation and yield ratio.
Smart Images
Figure KR2025095815_25062026_PF_FP_ABST