| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a steel pipe having excellent workability, which has satisfactory shape and surface properties, has excellent workability including a weld zone and is suitably usable for a steel pipe for structures purpose, piping or the like formed by tube drawing, bending, hydroforming or the like, and to provide a method for producing the same. Ž<P>SOLUTION: The steel pipe contains steel components each controlled within a prescribed range, and the metallic structure in the whole region of the steel pipe including a seam weld zone has a composite structure composed of ferrite and either or both of martensite and bainite, wherein the X-ray reflective face random strength ratio of the ä111} face of the sheet face in the 1/2 thickness of the steel pipe other than the seam weld zone lies in the range of 2.0 to 7.0, the X-ray reflective face random strength ratio of the ä110} face lies in the range of 1.0 to 5.0, and the X-ray reflective face random strength ratio of the ä100} face is ≤3.0. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž
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