Steel plate

EP4682282A4Pending Publication Date: 2026-06-24NIPPON STEEL CORPORATION
View PDF 5 Cites 0 Cited by

Patent Information

Application Number
EP2024770869
Authority / Receiving Office
EP · EP
Patent Type
Applications
Current Assignee / Owner
Priority Date
2023-03-13
Filing Date
2024-03-12
Publication Date
2026-06-24

AI Technical Summary

Technical Problem

Existing high-strength steel materials face challenges in maintaining both high strength and workability, particularly in applications requiring complex shapes and multiple deformation steps, such as automotive parts, due to reduced hole expandability and work hardening ability.

Method used

A steel sheet with a chemical composition comprising specific elements and a microstructure predominantly made of martensite, with controlled prior austenite grain size and orientation differences, enhancing work hardening ability and hole expandability.

Benefits of technology

The steel sheet achieves high tensile strength of 980 MPa or more while maintaining excellent work hardening ability and hole expandability, suitable for automotive applications.

✦ Generated by Eureka AI based on patent content.

Smart Images

  • Figure IMGB0001
    Figure IMGB0001
  • Figure IMGB0002
    Figure IMGB0002
  • Figure IMGB0003
    Figure IMGB0003
Patent Text Reader

Abstract

Provided is a steel sheet having a predetermined chemical composition, and a microstructure comprising, by area%, martensite: 90.0% or more and retained austenite: 3.0% or less, wherein a mean particle size of prior austenite grains is 30.0 µm or less, and when defining a region surrounded by grain boundaries with an orientation difference of 15° or more in the martensite as a "crystal grain", a ratio of crystal grains with an orientation difference in the grains of 4° or more is, by area%, 45.0 to 70.0%.
Need to check novelty before this filing date? Find Prior Art

Citation Information

Patent Citations

  • Hot rolled steel sheet and method for manufacturing same

    EP3584346A1

  • Hot-rolled steel sheet

    EP4098762A1

  • Steel sheet, member, method for producing said steel sheet, and method for producing said member

    EP4350016A1

  • Hot-rolled steel sheet and production method therefor

    US20210062289A1

  • Steel sheet, member, method for producing said steel sheet, and method for producing said member

    WO2023008003A1