Seamless expandable oil country tubular goods and manufacturing method thereof

摘要

A seamless expandable oil country tubular article, which has a superior pipe expansion property in a expanding process at an expand ratio of more than about 30% although having a high strength such as a tensile strength (TS) of about 600 MPa or more, and a manufacturing method thereof, the seamless expandable oil country tubular goods being in an as-rolled state or being processed, optionally necessary, by inexpensive nonthermal-refining type heat treatment.