| 摘要 |
<p>Embodiments of the present disclosure comprise carbon steels and methods of manufacturing thick walled pipes (wall thickness greater than or equal to about 35 mm) there from. In one embodiment, a steel composition is processed that yields an average prior austenite grain size greater than about 15 or 20 µm and smaller than about 100 µm. Based upon this composition, a quenching sequence has been determined that provides a microstructure of greater than or equal to about 50% by volume, and less than or equal to about 50% by volume lower bainite, without substantial formation of ferrite, upper bainite, or granular bainite. After quenching, the pipe may be subjected to tempering. The yield strength of the quenched and tempered pipes may be greater than about 65 ksi or 70 ksi and mechanical property measurements find the quenched and tempered pipes suitable for 65 ksi grade and 70 ksi grade, and resistance to sulfide stress corrosion cracking.</p> |
