Butt welding

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

Development and Application of the 3-Electrode MAG High-Speed Horizontal Fillet Welding Process

Abstract: In the shipbuilding industry, welding efficiency without deteriorating weld quality has been desired to, as a consequence of the recent increase in the amount of shipbuilding and the size of ship hulls. Especially, an innovation in the welding efficiency and weld quality in horizontal fillet welding is a more important issue, because the amount of horizontal fillet welding work generally accounts for 70 percent or higher of the total welding work for ship hulls. One of high-speed horizontal fillet welding processes known as “Twin Tandem One Pool process” has been used in actual fabrication. However, the maximum welding speed of the twin tandem one pool process is approximately 1.5 m/min. In order to increase welding speed and welding quality of the twin tandem one pool process, the authors have employed an additional filler wire positioned between the two wires of the twin tandem one pool process. The additional wire carries DC-EN currents, opposite to DC-EP currents for the main welding wires, thereby reducing arc interference and arc blow at high currents. With this new technique, the authors have improved the stability of the weld pool formation at high currents. Consequently, horizontal fillet welding at a speed of 2.0 m/min on primer-coated steel plates has been achieved with excellent bead appearance, shape, and porosity resistance. Recently, this new process has just been installed in actual shipbuilding and it is confirmed that it truly contributes to improve welding efficiency and minimize repair time.

Transient and residual stresses in a single-pass butt welded pipe

Abstract: The development of stresses and strains during butt welding of a thin walled pipe is followed numerically by use of the finite element method (FEM) and, in parallel, measured experimentally. Three different FE-models of the pipe, one fully three dimensional, one rotationally symmetric and one shell type, were used in the numerical part of the study. For all three models the pipe material was taken as thermo-elasto-plastic with strongly varying temperature dependent material properties. Calculated results for the weld metal and HAZ were found to be heavily dependent on the constitutive modelling of the final phase transformation. The qualitatively best agreement with the experiments for the residual stress field was obtained with a simplified FE-model which did not consider such effects. During welding, the transient stress field was found to be strongly rotationally nonsymmetric.

Apparatus for connecting strips

Abstract: An apparatus for connecting strips, in which a rear end portion of a preceding strip and a front end portion of a succeeding strip are cut and brought into contact to each other so that a butt welding of the contacted portions may be carried out to connect both the strips. A carriage is provided for carrying a cutting device for cutting the end portions of both the strips. A finish-machining device is provided for finish-machining the cut end faces of both the strips and a welding device for butt welding both the strips along a contacting line of both the strips is installed so as to be movable in a line substantially parallel with the contacting line of both the strips. Die wears and burrs incidental to cut faces can be prevented from forming and the highly accurate contacted state of strips can be achieved, thereby improving the quality of the welded portion.