Butt welding

About: Butt welding is a research topic. Over the lifetime, 7153 publications have been published within this topic receiving 44467 citations.

Improving of interfacial microstructure of Ti/Al joint during GTA welding by adopting pulsed current

Abstract: Butt welding of titanium alloy TA15 to aluminum alloy Al2024 dissimilar lightweight metals was conducted using gas tungsten arc welding. Pulsed current was adopted in the welding process. Influence of pulsed current on morphologies and microstructure of Ti-Al intermetallics near the Ti/Al interface was investigated. Microstructure characteristics and phase constitution of weld zone near the Ti/Al interface were analyzed. In top surface and upper region of the joint, Ti base metal was partially melted, and continuous intermetallic layers with Ti3Al, TiAl, and TiAl3 were formed in the fusion zone. In middle and bottom regions of the joint, Ti base metal was not melted and a thin TiAl3 layer was formed near the Ti/Al-brazed interface. Most of the Ti-Al intermetallics formed into discrete TiAl3 precipitations in the weld metal in upper and middle regions of the joint. No precipitation was observed in bottom region of the joint. Thickness of continuous Ti-Al intermetallic layers in the fusion zone was controlled at a low degree by adopting pulsed current in the welding. Crack sensitivity of weld zone near the Ti/Al interface was decreased.

Welding technology for butt welding of composite boards

Abstract: The invention discloses a welding technology, in particular a welding technology for butt welding of composite boards, which can guarantee the mechanical property of butt-jointed seam of composite boards and can meet the requirements for the anticorrosion of the welding seams. The welding technology is characterized in that a composite layer and a base layer of the composite board are reversely welded before welding so that the metals in other parts can not be fused to the welding beveled edges in welding seam metals when welding the base layer or the composite layer; the welding materials of which content of main alloys is higher than the content of the main alloys in the composite layer are selected when a transition layer is welded; the root of the base layer or the root of the composite layer is firstly welded and the transition part of the transition layer is then welded in the course of welding when the transition layer is welded; and the welding current is selected the higher limit specified in the specification of welding materials and the welding voltage and the welding rate are selected the lower limits specified in the specification of the welding materials in the selection of welding parameters.

Comparison of Mechanical and Metallurgical Properties of Modified 9Cr–1Mo Steel for Conventional TIG and A-TIG Welds

Abstract: This work attempts to investigate the effect of flux activation on mechanical and metallurgical properties of modified 9Cr–1Mo steel during activated TIG (A-TIG) welding. Composition-based oxide flux MnO2 was identified to produce a 6-mm-thick square-groove butt weld joint in P91 steel plates considering the satisfactory bead penetration during “bead-on-plate” experiment. During the experiment, it was found that using MnO2, the process of “A-TIG” can increase the penetration of the joint and depth-to-width ratio (D/W) of the weld for welding P91 steel up to 231% and 0.93 respectively. The base metal and the multipass GTA weld joint’s mechanical properties have been compared with the modified 9Cr–1Mo steel A-TIG weld joint. To study other metallurgical aspects of the TIG and A-TIG process, tests such as microhardness, tensile, bend, impact test and chemical analysis were performed. Optical microscopy was used to conduct the characterization of microstructure.

Method for repairing gas turbine blade, its repairing device, and gas turbine blade

Abstract: PROBLEM TO BE SOLVED: To facilitate the automatic welding by cutting a deteriorated tip part of a gas turbine rotor blade, finishing the surface, and performing the welding by cladding. SOLUTION: A gas turbine rotor blade 1 having a deteriorated part 2 at the tip part is repaired by the welding by cladding. The tip part including the deteriorated part is cut or ground to the prescribed shape. A surface 4 to be welded by cladding is of the constant shape. Because the shape is constant, the welding conditions such as the welding current, the welding voltage and the arc length can be easily set, and the heat input can be easily controlled. Every rotor blade 1 can be executed under the constant welding conditions, and when the set condition is once inputted, a large number of rotor blades 1 can be repaired under the same condition, and the time of execution can be greatly reduced. The quality of a weld zone 5 by cladding is not dispersed for each rotor blade 1, but is uniform. The sound weld zone 5 by cladding free from any defective welding can be formed.

Method and apparatus for twin spots pulse laser welding

Abstract: A twin spots pulse laser welding apparatus is disclosed which is used for providing a defect-free weld in a butt welding gap. The welding apparatus comprises a YAG laser oscillator 6, a chopper circuit for controlling the value of the lamp current of the oscillator, a chopping controller 12, a control panel 10 and a pulse generator 11 for applying a lamp current base value Wb and a peak value Wp and a pulsating pulse to the controller, and a twin spots laser head 14 for converging a laser beam delivered from the YAG laser oscillator to two foci 20R, 20L which are distributed in x direction with a very small spacing therebetween. YAG laser beam delivered from the YAG laser oscillator 6 is guided through an optical fiber cable 9 to the laser head.