| 摘要 |
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 tm and smaller than about 100 tm. 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 450 MPa or 485 MPa and mechanical property measurements find the quenched and tempered pipes suitable for 450 MPa grade and 485 MPa grade, and resistance to sulfide stress corrosion cracking. L) 102 Steel Making 104 Hot Forming 106A Austenizing 106B Quenching 106C H Tempering 110 Finishing |
