| 摘要 |
A steel for oil country tubular goods includes, as a chemical composition, by mass %, C, Si, Mn, Al, Mo, P, S, O, N, and a balance containing Fe and impurities, wherein a full width at half maximum HW of a crystal plane corresponding to a (211) crystal plane of an α phase and a carbon content expressed in mass % in the chemical composition satisfy HW×C≤0.38, the carbon content and a molybdenum content expressed in mass % in the chemical composition satisfy C×Mo≥0.6, a number of MC carbides having a hexagonal crystal structure and having an equivalent circle diameter of 1 nm or more is 5 pieces or more per one square micron, and an yield strength is 758 MPa or more. |
