| 摘要 |
A flange disk-welded steel pipe includes: a flange disk which includes a flange portion having a flat ring shape, and a connection portion which is positioned at an outer circumferential side of the flange portion and has an annular portion in which at least a portion protrudes from one surface side of the flange portion; a steel pipe which is welded to the one surface side of the connection portion and has a pipe thickness t; and a weld metal portion which is formed by welding between the connection portion and the steel pipe, in the cross-section including a pipe axis of the steel pipe, of the weld metal portion, a cross-sectional area So of an outer circumferential side from a center of the steel pipe in a pipe thickness direction of the steel pipe and a cross-sectional area S I of an inner circumferential side of the steel pipe satisfy a relationship of S O ‰¥1.5S I , and a distance, between a weld toe of a flange portion side in an inner surface side of the weld metal portion and a flange corner which is a portion where an inner surface of the connection portion and the one surface of the flange portion cross, is 5 mm or more and the pipe thickness t or less. |
