Steel pipe for use in reinforcement of automobile and method for production thereof
US7018488B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 14, 2001 |
| Grant date | Mar 28, 2006 |
| Priority date | — |
| Expiry date | Jul 16, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/008
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A steel tube having a composition which contains: 0.05 to 0.30% of C; 1.8 to 4.0% of Mn; Si; and Al is subjected to a diameter-reducing rolling process in which the total diameter-reduction rate is no less than 20% and the temperature at which the diameter-reducing rolling process is finished is no higher than 800° C., whereby a structure constituted of martensite and/or bainite or further of ferrite is obtained as a transformation product from the deformed γ. As a result, a steel tube having tensile strength of 1000 MPa or more and excellent three-point-bending property can be obtained. The composition of the steel tube of the present invention may further include at least one type of element selected from the group consisting of Cu, Ni, Cr and Mo, or at least one type of element selected from the group consisting of Nb, V, Ti and B, or at least of one type selected from the group consisting of REM and Ca.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.