METHOD FOR PRODUCING A STEEL PIPE USING A HIGH DENSITY ENERGY BEAM

摘要

A method for producing a steel pipe using a high density energy beam, comprises the steps of: (a) forming a steel strip having two edges into 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 against each other by using squeeze rolls to form a joint portion; (d) irradiating 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 using the squeeze rolls enough to reduce a weld defect.