Seamless steel pipe and method for manufacturing the same
US8317946B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 20, 2011 |
| Grant date | Nov 27, 2012 |
| Priority date | — |
| Expiry date | Apr 20, 2031 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC21D2211/004
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A seamless steel pipe of a low-alloy steel consisting, by mass %, of C: 0.10 to 0.20%, Si: 0.05 to 1.0%, Mn: 0.05 to 1.2%, Ni: 0.02 to 1.5%, Cr: 0.50 to 1.50%, Mo: 0.50 to 1.50%, Nb: 0.002 to 0.10%, Al: 0.005 to 0.10%, and either or both of Ti: 0.003 to 0.050% and V: 0.01 to 0.20%, the balance being Fe and impurities, the impurities containing 0.025% or less of P, 0.005% or less of S, 0.007% or less of N, and less than 0.0003% of B, wherein the tensile strength is 950 MPa or more and the yield strength is 850 MPa or more, and the Charpy absorbed energy at −40° C. is 60 J or more. This seamless steel pipe may further contain one or more of Cu: 0.02 to 1.0%, Ca: 0.0005 to 0.0050%, and Mg: 0.0005 to 0.0050%. The present invention also provides a method for manufacturing the above-described seamless steel pipe.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.