Hot-rolled steel strip for high strength electric resistance welding pipe and manufacturing method thereof
US7501030B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 24, 2004 |
| Grant date | Mar 10, 2009 |
| Priority date | — |
| Expiry date | Mar 24, 2024 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/002
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A hot-rolled steel strip having superior low temperature toughness and weldability, which is suitably used as a starting material for high strength electric resistance welding pipe, is provided at a low cost without constructing new production facilities and increasing cost. The hot-rolled steel strip is low carbon steel containing at least one of about 0.5.% or less of Cu, about 0.5% or less of Ni, and about 0.5% or less of Mo, wherein Pcm represented by the following equation (1) is 0.17 or less:Pcm=(% C)+(% Si)/30+((% Mn)+(% Cu))/20+(% Ni)/60+(% Mo)/7+(% V)/10 Equation (1),(where (% M) indicates the content of element M on a mass percent basis), and the balance includes Fe and incidental impurities. In addition, in the entire microstructure, the ratio of bainitic ferrite, which is a primary phase, is controlled to be about 95 percent by volume or more.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.