Method for producing a steel pipe using a high density energy beam
AssigneeNKK Corporation
InventorsMoriaki Ono, Tsuyoshi Shiozaki
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Abstract
A method of producing a welded steel pipe which comprises: (a) forming a steel strip having two edges in a cylindrical form so that the two edges face each other; (b) preheating the two edges of the steel strip to a temperature of a melting point or less by applying a high frequency electric current to the two edges; (c) pressing the two edges of the steel strip towards each other by contact with squeeze rolls to form a joint portion including a joint line; (d) radiating a high density energy beam sufficient to fuse a full thickness of the steel strip to a portion adjacent to a squeeze point to weld the joint portion; and (e) controlling an upset by applying the squeeze rolls sufficiently to reduce weld defects.
Claims5
A method for producing a welded steel pipe comprising the steps of:
- (a) forming a steel strip into an open pipe having two edges;
- (b) joining the two edges of the open pipe to form a joint portion;
- (c) radiating a high density energy beam to the joint portion to weld the joint portion, the high density energy beam having a beam axis and an irradiation point, the beam axis being inclined toward the joint portion, wherein said high density energy beam has an inclination of 5 to 20 degrees and the inclination is an angle between the beam axis and a vertical line at the irradiation point.
Dependencies are inferred from the claim text.