| 摘要 |
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. |
