Hot-rolled steel sheet for high-strength electric-resistance welded pipe having sour-gas resistance and excellent weld toughness, and method for manufacturing the same
US7879287B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 3, 2005 |
| Grant date | Feb 1, 2011 |
| Priority date | — |
| Expiry date | Jun 11, 2026 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22C38/16
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A hot-rolled steel sheet for high-strength ERW pipes contains about 0.02% to about 0.06% C; about 0.05% to about 0.50% Si; about 0.5% to about 1.5% Mn; about 0.010% or less P; about 0.0010% or less S; about 0.01% to about 0.10% Al; about 0.01% to about 0.10% Nb; about 0.001% to about 0.025% Ti; about 0.001% to about 0.005% Ca; about 0.003% or less 0; and about 0.005% or less N, and at least one element selected from the group consisting of about 0.01% to about 0.10% V; about 0.01% to about 0.50% Cu; about 0.01% to about 0.50% Ni; and about 0.01% to about 0.50% Mo on the basis of mass. The group of C, Si, Mn, Cu, Ni, Mo, and V and the group of Ca, 0, and S satisfy specific relationships, and the microstructure of the steel sheet is composed of about 95% by volume or more bainitic ferrite.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.