Patent ID: 8821653
Filing Date: 2014-09-02
Classification: C21D,C22C,E21B

Abstract:
1. A heavy wall seamless steel pipe, comprising: a steel composition comprising: wherein the wall thickness of the steel pipe is greater than or equal to 35 mm; and wherein the steel pipe is processed to have a yield strength greater than or equal to 450 MPa, wherein the microstructure of the steel pipe consists essentially of martensite and lower bainite, wherein martensite is in a volume percentage greater than or equal to 50% and lower bainite is in a volume percentage less than or equal to 50%, and wherein the steel pipe does not exhibit failure due at least in part to stress corrosion cracking after 720 hours when subjected to a stress of 90% of the yield stress and tested according to NACE TM0177.