Abstract: Deep penetration gas tungsten arc welds are achieved using titanates such as Na2Ti3O7 or K2TiO3. A small amount of the titanate is applied to the weld zone in a carrier fluid paste or as part of a wire filler to afford deep penetration welds in carbon, chrome-molybdenum, and stainless steels as well as nickel-based alloys. To control arc wander, bead consistency, and slag and surface appearance of the weldments, various additional components may be optionally added to the titanate flux including transition metal oxides such as TiO, TiO2, Cr2O3, and Fe2O3, silicon dioxide, manganese silicides, fluorides and chlorides. However, the toxicity of the plumes from halide additives and the necessity of post-weld removal to prevent corrosion may preclude their use. In addition, it was found that a flux of titanium oxides, Fe2O3 and Cr2O3 affords deep weld penetration in carbon steels and nickel-based alloys but with some heat-to-heat variation.

Abstract: To overcome 1) the high levels of porosity due to coating material vaporization and entrapment into the weld, 2) spewing of molten base metal from the weld leaving holes and pits in the weld, and 3) humping effects when oblong beam configurations are used at higher weld speeds to weld coated materials, the present invention features an energy source (10) with multiple separated energy beams (24, 26) (formed by using multiple separate beam sources or manipulation of a single beam (14) into separated multiple energy beams (44, 46) using wedge mirror (18) and parabolic focusing mirror (20)) that produces high quality (porosity free) lap welds in a weld stack (50) of layered materials (30, 32) coated with coating material (28, 28′, 34, 34′) with zero gap at interface (38) during the welding process.

Abstract: A method for production of simultaneous lap and butt joints directs electromagnetic radiation (12) through a radiation transmitting material (40) to an absorbing material (44a, 44b, and 44c) that absorbs radiation (12) with the generation of heat. The heat provides sufficient molten material in interfaces (50a, 50b, and 50c) to fuse and bond: 1) pipe ends (14, 24) to each other in a butt joint (22), 2) pipe end portion (16) to sleeve (40) in a lap joint (28a), and 3) pipe end portion (26) to sleeve (40) in a lap joint (28b). Use of a sufficiently clear material for sleeve (40) allows visual inspection of joints (22, 28a, and 28b). Butt joint (22) can be formed by conductive heating without absorbing material (44a) to provide a smooth interior bore useful for transporting high purity fluids without risk of absorbent contamination or debris and organism collection in gaps found in previous joining techniques.