Steel material for line pipes, method for producing the same, line pipe, and method for producing the line pipe
US12227814B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 19, 2020 |
| Grant date | Feb 18, 2025 |
| Priority date | — |
| Expiry date | Oct 20, 2041 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P10/25
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A steel material for line pipes has a specific composition. The metallic microstructure of the steel material at a ⅛-plate thickness position below the surface includes bainite of an area fraction of 85% or more, polygonal ferrite of an area fraction of 10% or less, and martensite-austenite constituent of an area fraction of 5% or less. The 0.23% compressive strength of a portion of the steel material which extends from the surface to the ⅛-plate thickness position in a transverse direction is 340 MPa or more. The temperature at which a percent ductile fracture of the steel material measured in a DWTT test becomes 85% or more is −10° C. or less.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.