Title:
SEAMLESS STEEL PIPE FOR LINE PIPE USED IN SOUR ENVIRONMENT
Document Type and Number:
WIPO Patent Application WO/2014/192251
Kind Code:
A1
Abstract:
Provided is a seamless steel pipe that is for use in a line pipe that is used in a sour environment, that does not require hardening or tempering to be performed, and that makes it possible to minimize the occurrence of blisters. A seamless steel pipe according to an embodiment of the present invention is provided with: a chemical composition comprising, in mass%, 0.08-0.24% of C, 0.10-0.50% of Si, 0.3-2.5% of Mn, 0.02% or less of P, 0.006% or less of S, 0.02-0.12% of Nb, 0.005-0.100% of Al, 0.0003-0.0050% of Ca, 0.0100% or less of N, 0.0050% or less of O, 0-0.1% of Ti, 0-0.03% of V, 0-0.6% of Cr, 0-0.3% of Mo, 0-0.4% of Ni, 0-0.3% of Cu, 0-0.005% of B, and a remainder of Fe and unavoidable impurities; and a structure comprising ferrite and pyrite. The seamless steel pipe has a yield strength of 350 or more and less than 450 MPa.
Inventors:
KOBAYASHI KENJI (JP)
ARAI YUJI (JP)
ARAI YUJI (JP)
Application Number:
PCT/JP2014/002662
Publication Date:
December 04, 2014
Filing Date:
May 21, 2014
Export Citation:
Assignee:
NIPPON STEEL & SUMITOMO METAL CORP (JP)
International Classes:
C22C38/00; C21D8/10; C22C38/58
Domestic Patent References:
| WO2005075694A1 | 2005-08-18 | |||
| WO2011152240A1 | 2011-12-08 |
Foreign References:
| JPS63250418A | 1988-10-18 | |||
| JPH01234521A | 1989-09-19 | |||
| JPS59150066A | 1984-08-28 | |||
| JP2012509398A | 2012-04-19 | |||
| JP2002060893A | 2002-02-28 |
Other References:
See also references of EP 3006585A4
Attorney, Agent or Firm:
M. MORI PATENT FIRM (JP)
Patent business corporation Woods Michio patent firm (JP)
Patent business corporation Woods Michio patent firm (JP)
Download PDF: