| 摘要 |
In this steel-pipe shaping method, in which a raw steel sheet is made into a substantially cylindrical shape via a first-half shaping process whereby three-point bending is performed a plurality of times from one widthwise edge of the raw steel sheet to the widthwise center thereof, a second-half shaping process whereby three-point bending is performed a plurality of times from the other widthwise edge of the raw steel sheet to the widthwise center thereof, and a final shaping process whereby three-point bending is performed on the widthwise center of the raw steel sheet, by dividing the first-half shaping process into a preceding shaping process performed before the second-half shaping process and a following shaping process performed after the second-half shaping process and setting the extent over which shaping is performed in the preceding shaping process to more than 0.17 but less than 0.46 times the width of the steel sheet, the maximum diameter with which steel pipes can be manufactured is increased without modifications to an existing press. |
