| 摘要 |
<p>A thick-walled seamless steel pipe for line pipe which has a high strength and improved toughness and corrosion resistance in spite of the thick wall and which is suitable for use as a riser and flow line has a chemical composition comprising, in mass percent, C: 0.02 - 0.08%, Si: at most 0.5%, Mn: 1.5 - 3.0%, Al: 0.001 - 0.10%, Mo: greater than 0.4% - 1.2%, N: 0.002 - 0.015%, at least one of Ca and REM in a total amount of 0.0002 - 0.007%, and a remainder of Fe and impurities, with the impurities having the content of P: at most 0.05%, S: at most 0.005%, and O: at most 0.005%, the chemical composition satisfying the inequality: 0.8 ‰ [Mn] x [Mo] ‰ 2.6, wherein [Mn] and [Mo] are the numbers equivalent to the contents of Mn and Mo, respectively, in mass percent.</p> |
