| 摘要 |
Provided is a method for producing a welded steel pipe having excellent buckling resistance. The method for producing a welded steel pipe according to the present embodiment includes steps of: preparing a welded pipe, and expanding the welded pipe over the entire length thereof by using a pipe expanding head such that an undulation wavelength ratio D defined by Formula (1) is not more than 0.8, or not less than 1.8: D = p/.lambda. (1), where p is an undulation wavelength in the axial direction of the welded steel pipe, and A. is a Timoshenko's buckling wavelength as defined by Formula (2): .lambda.. = 3.44 x (r x .tau.)1/2 (2), where r is an inner radius of the welded steel pipe and t is a wall thickness of the welded steel pipe. |
