Butt welding

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

Quality control of laser welds of tailored blanks using guided waves and EMATs

Abstract: In modern design of automobile bodies reduction in weight and maximisation of the structural stiffness and passive safety are the main challenge. The ‘tailored blank’ has contributed to achieving a significant weight reduction in recent years. Single flat sheets are joined by laser welding into the desired configuration without filler wire. Usually the quality of the welds is assured by precise preparation of the plate edges and measurement of two of the process parameters. However, due to process deviations, defects occur, which make non-destructive testing (NDT) necessary. These defects include incomplete welding, lack of fusion, misalignment of the weld, holes and porosity. The paper presents a versatile ultrasonic (UT) inspection technique designed for in-line inspection of laser welds of tailored blanks. Conventional ultrasonic tetsing is ruled out because of the necessary liquid coupling medium. Therefore, the proposed inspection approach is based on the application of guided ultrasonic (plate) waves with shear horizontal polarisation excited and detected by couplant-free electromagnetic acoustic transducers (EMATs).

Method of drawing fiber continuously by butt welding optical fiber preforms

Abstract: In the method of drawing fiber continuously from preforms for manufacturing an optical fiber, a first preform is displaced along a fiber-drawing axis and is drawn into an optical fiber through a fiber-drawing furnace disposed on the fiber-drawing axis, and a second preform is displaced along the fiber-drawing axis, which second preform is butt welded to the first preform so as to be drawn into an optical fiber following on from the first fiber. The two preforms are butt welded, i.e. they are welded together end-to-end, by displacing at least one power laser along the fiber-drawing axis, and by servo-controlling the displacement of said laser to the displacement of the two preforms so as to maintain a laser beam emitted by the power laser at the same height as the two ends to be welded together, thereby making it possible to reduce considerably the size of the zone affected by the welding, and to avoid polluting the side surfaces of the two preforms upstream and downstream from the weld.

Apparatus and method for connecting pipes by welding

Abstract: Apparatus and method for connecting by welding two axially spaced apart pipes which may be misaligned relative to each other, including butt welding between the pipe ends a pair of coupling members, each coupling member having a tubular portion and an end portion having a face which lies on a plane which intersects the axis of the tubular portion at a nonperpendicular angle and which describes the circle upon the plane. The faces of the end portions may be abutted, rotated, and welded together such that the axes of the tubular portions thereof intersect at various angles. In one embodiment of the invention, the coupling members are mounted in combination with a pair of tubes, each of the tubes has a radially enlarged ring near one end thereof, which end is butt welded to one of the pipe ends. The coupling members are slidingly mounted over the tubes in telescopic fashion, and fixed upon the tubes by fitting a split sleave over the tube between the ring thereon and the end of the tubular portion of the coupling member, which is then butt welded in place. In an alternate embodiment of the invention, the coupling members are mounted between the pipe ends by butt welding the tubular portions directly to the pipe ends. The apparatus and method of this invention are particularly useful for use in an underwater environment.

Computer-aided analysis of repair welding of stamping tools

Abstract: The paper deals with computer-aided repair welding of a damaged metal-working tool, i. e., a stamping tool. To repair an uncomplicated tool, TIG (Tungsten Inert Gas) welding with a filler material was used. In the process of welding, the welding parameters and the temperature at the workpiece were measured. The major part of the paper describes the use of a personal computer as an aid to calculate the temperature distributions in the workpiece in the process of welding and after welding, and the cooling rate after welding. To this end, the Microsoft Excel software was used. The cooling curves obtained for the individual parts of the workpiece after welding were plotted in a TTT (Time Temperature Transformation) diagram to determine the workpiece structure, hardness and, indirectly, other mechanical properties. The most important finding is that the method described permits to find the locations of maximum stresses in the work-piece that may be potential sources of crack formation.

Automatic seam tracking in pipeline welding with narrow groove

Abstract: Automatic welding has been used frequently on pipeline projects. Productivity and reliability are the most essential features of automatic welding system.While the mechanized GMAW process is the most widely used welding process, the carriage and band system is the most effective welding system for pipeline laying. This application-oriented paper introduces a new piece of automatic welding equipment used in the dual tandem welding process for pipeline construction. It is based on cutting-edge design and practical welding physics to maximize productivity. This paper also describes the control system that was designed and implemented for automatic welding equipment. The system has the self diagnostic function which facilitates maintenance and repairs, and also has the network function via which the welding task data can be transmitted and the welding process data can be monitored. The arc sensor was also developed for a narrow welding groove in order to achieve higher accuracy of seam tracking and fully automatic operation.