The Research On Welding Torch And Root Welding Technology In Ultra-narrow Gap Welding

Ultra-Narrow Gap welding (UNGW) has high production efficiency,excellent performance in welded joint and important application value to material in need of low welding heat input. This paper combined with the advantages of successive feeding flux strips and the present type flux,with developing a new structure of the flux. Flux with a new structure not only improves the rigidity of the welding process to ensure that the flux into the arc with stability; and with the new structure to adapt to long-distance welding flux, can be sent to ensure the continuity of the welding process. Flux with the new structure was developed to match with the ultra narrow gap welding torch. UNGW welding torch structure is more simple, excluding delivery with the speed of the welding process. Flux with the use of new structures and send with a torch at different speeds for ultra-narrow gap welding, wire feed by comparing the effects of different weld speeds, we know that the new structure of the weld with the welding process can be very stable continuous constraints arc, and the gun has to meet different welding wire feed speed.UNGW welding in butt welding has a unique advantage, in addition to increasing productivity, it also can adjust the stress state of the weld. In the actual welding butt welding projects generally require the use of melt-through bead achieve root welding, root welding quality is the basis of the welding quality, so the UNGW welding method of welding is the root of ultra narrow gap applied to the butt welding an important part of welding. This type of groove in the design of flux within the constrained ultra-narrow gap arc welding root welding test and achieve side welding shape. The results show that the use of welding method for forming the back of freedom, relying on surface tension of molten metal bath to prevent leakage and the formation of the back of the weld under the method does not work. Liner only with the back of the workpiece forming method despite the flux of force to achieve a side welding forming, but only in a certain distance from the back seam to maintain a good shape. This is because late in the welding flux and the growing distance between the workpiece caused by the pool below the flux of the liner does not fall off occurs, and produce pores. The use of flux - copper liner forming method can force the flux in the cooling time after the formation of molten slag, the slag pool liner below the moment, it is not falling, so that the back of the weld good shape.In addition, tests designed for this type of groove, formed to achieve the effect of side welding, in addition to the use of appropriate welding standard match, the wire angle, flux and flux bedding thickness of the particle size is also constrained to achieve ultra-flux Narrow gap welding side welding of three important factors shaping. When the wire relatively small tilt angle of the vertical or when the pool during the welding process there will be a cutting-edge groove width slightly greater than 1 ~ 2 mm of the fusion pore, and the melt holes in the welding seam is still at work after the end. The wire back tilt angle, can melt pore size decreases, the posterior slope angle of 60°or so you can melt holes eliminated. Bedding under the work piece size of particle flux also has a certain influence on the weld shape. Flux particle size is too small, the workpiece in the welding process causes the gas too late to escape the bottom, thus forming a stoma. When the flux particles greater than 9 orders, you can weld a good solution to the problems there holes.