| 摘要 |
PROBLEM TO BE SOLVED: To obtain a weld zone free of welding defects and also superior in mechanical characteristics by controlling the relation between the irradiation position and the welding speed of a high energy beam. SOLUTION: In the welded steel pipe manufacture in which, in a squeezing stand equipped with squeezing rolls 5 for continuously forming a steel belt into a cylindrical open pipe 6 by a series of roll groups, the butt end of the open pipe 6 is irradiated with a high energy beam 7 and continuously welded; the beam 7 is emitted to the butt part at the entrance of the squeezing rolls 5; and the time until the irradiation part of the beam 7 passes the center line of the squeezing rolls 5 is limited within the range of 0.15 to 0.30 sec. |
