Apparatus and method for trackless movement and full penetration arc welding

摘要

An apparatus, system and related method are disclosed for performing trackless movement and full penetration welding along a weld line, irrespective length and configuration of a butt joint. A pre-existing gap of the weld line is used to act a guide slot and a guide wheel unit to track the gap is designed to perform trackless movement using an electric or manual winch as a driver. In the automatic arc welding systems, the guide slot and the guide wheel unit can save an external track and a seam-tracking device. A movable weld backing is held against the underside of the weld line to support liquid metal and control backside bead to achieve full-penetration welding of a butt weld. The movable weld backing and a welder are arranged the underside and the topside of base metals to be welded, respectively, using a connector member through the pre-existing gap of the weld line. According to the apparatus, flux-cored wire plasma arc can perform full penetration welding. A layer of liquid slag between the moveable backing and the liquid metal of the underside weld pool can act as a lubricant to increase the sliding ability of the moveable backing, act as a heat insulator to protect the backing from the high temperature of plasma arc, and provide a shielding film for the weld pool.