Seamless steel pipe and method of manufacture thereof
US12338942B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 21, 2021 |
| Grant date | Jun 24, 2025 |
| Priority date | — |
| Expiry date | Nov 12, 2041 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C38/54
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A seamless steel pipe has a t/Dout of 0.05 to 0.40, where t is a wall thickness (mm) of the seamless steel pipe, and Dout is an outside diameter (mm) of the seamless steel pipe. The seamless steel pipe has a maximum depth dmax (mm)≤0.350 mm for defects in an inner surface of the steel pipe on a cross section perpendicular to a pipe axis. The seamless steel pipe has an average defect depth dave (mm)≤0.200 mm for defects having a depth of 0.050 mm or more in the inner surface of the steel pipe. The seamless steel pipe, per millimeter of an inner circumferential length of the pipe, has at most 30 defects having a depth of 0.050 mm or more in the inner surface of the steel pipe.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.