It indicated that double wire welding technique not only advanced the efficiency of welding and quality of weld seam but also improve the tensile strength and facture toughness of the welded joints.

• 根据螺旋焊管内焊双丝焊工艺的特殊性,研制了一套内焊双丝焊装置,该装置由焊丝对缝跟踪机构、焊臂支撑导向机构、送丝系统、调节机构及导电焊炬等组成。