Welding high-strength aluminum alloys

Handbook has been published which integrates results of 19 research programs involving welding of high-strength aluminum alloys. Book introduces metallurgy and properties of aluminum alloys by discussing commercial alloys and heat treatments. Several current welding processes are reviewed such as gas tungsten-arc welding and gas metal-arc welding

Welding torch with arc light reflector

A welding torch arc light reflector is disclosed for welding torches having optical viewing systems. A schematic of a welding torch having an internal coaxial viewing system consisting of a lens which focuses the field of view of the weld scene of the workpiece onto the end of the fiberoptic bundle is provided. The transmitted image of the fiberoptic bundle is provided to a camera lens which focuses it onto a TV sensor array for transmission. To improve the parity of the image of the monitoring system, an arc light reflector is shown fitted to the end of the torch housing or gas cup. The arc light reflector has an internal conical section portion which is polished to serve as a mirror which reflects the bright arc light back onto the darker areas of the weld area and thereby provides a more detailed image for the monitoring system. The novelty of the invention lies in the use of an arc light reflector on welding torches having optical viewing systems

Grain refinement control in TIG arc welding

A method for controlling grain size and weld puddle agitation in a tungsten electrode inert gas welding system to produce fine, even grain size and distribution is disclosed. In the method the frequency of dc welding voltage pulses supplied to the welding electrode is varied over a preselected frequency range and the arc gas voltage is monitored. At some frequency in the preselected range the arc gas voltage will pass through a maximum. By maintaining the operating frequency of the system at this value, maximum weld puddle agitation and fine grain structure are produced

Comparison between friction stir and submerged arc welding applied to joining DH36 and E36 shipbuilding steel

With the impending development of FSW tools for steel with useful lifetimes, attention has turned to the mechanical properties of the welds that can be made in a range of industrially significant steels. This work reports on a comparative study undertaken to examine the use of friction stir and submerged arc welding on DH36 and E36 shipbuilding steels. The study made an assessment of the distortion induced in fabricating plates by the two welding techniques, and provides initial comparative data on weld tensile strength, toughness and fatigue life. In each case, friction stir welding was shown to outperform submerged arc welding

Vacuum vapor deposition: A spinoff of space welding development

A vapor deposition process has been defined through a spinoff effort of space welding development. In this development for welding in a space environment, a hollow electrode was used to add gas precisely at the welding arc. This provides gas for ionization which carries the welding arc current. During this welding development metal vapor coatings were observed. These coatings are unique in that they are produced by a new process. Some coatings produced and the potential of this new and innovative vapor deposition process are characterized. Advantages over prior art are discussed

Closed circuit TV system automatically guides welding arc

Closed circuit television /CCTV/ system automatically guides a welding torch to position the welding arc accurately along weld seams. Digital counting and logic techniques incorporated in the control circuitry, ensure performance reliability

Spinarc gas tungsten arc torch holder

Semiautomatic welding torch enables operator to control arc length, torch angle, and spring tension when welding small diameter aluminum tubing. Tungsten is preset for the weld to make arc initiation easier and to eliminate searching for the joint through a dark welding lens

Effect of torch angle on arc properties and weld pool shape in stationary GTAW

In this paper, a three dimensional numerical simulation is performed on a stationary arc to study the effect of torch angle in gas tungsten arc welding (GTAW) of SS304 stainless steel. A comparison has been made to investigate 90o and 70o torch angles and analyze the effect on arc and weld pool shape. Current density, heat flux and gas shear stress are calculated in the arc region and are used as input to the workpiece to determine the weld pool. Buoyancy and Marangoni shear also affect the weld pool shape and are taken into account. The computed and experimental results are observed symmetric for 90o torch angle. For 70o torch angle, current density and hence the heat flux due to electron contribution is found the maximum behind and heat flux due to conduction and convection is found the maximum ahead of the electrode tip in the welding direction. This makes the maximum of total heat flux symmetric along the arc center. Heat flux due to conduction and convection decreases as the torch angle decreases resulting in a shallow weld pool. The nonsymmetric “w” shaped weld pool is developed by the combined effect of the gas shear and Marangoni convection. It is found that for 70o torch angle, the weld pool becomes non-symmetric, shallow and wide ahead of the electrode tip in the welding direction. The numerical weld pool shapes are verified through experiments

THE EFFECT OF LEARNING DEMONSTRATION METHOD ON THE LEARNING ACHIEVEMENT IN SMAW PRACTICE AT SMK N SUKAMAJU

The research purposes are : (1) to know the learning achievement of students in grade XI SMK N Sukamaju on manual arc welding subject of horizontal fillet positions which are taught with the demonstration method, (2) to know the learning achievement of students in grade XI SMK N Sukamaju on manual arc welding subject of horizontal fillet positions which are taught with the lecture method, (3) to know the difference in learning achievement of students in grade XI SMK N Sukamaju manual arc welding subject of horizontal fillet connections which are taught by demonstration method with taught by lecture method The research is one of pretest-posttest Control Group DesignS which compare an experiment group and the control group. This research i population of the study was a XI class student of Welding Engineering Department SMK N Sukamaju with 28 students. The data were analyzed with descriptive statistical techniques. The research product shows: (1) the learning achievement of students in grade XI SMK N Sukamaju on manual arc welding subject of horizontal fillet positions which are taught with the demonstration method (experiment group) obtained the highest score of 87, lowest score of 83, and the mean amounted to 84,21; (2) the learning achievement of students in grade XI SMK N Sukamaju on manual arc welding subject of horizontal fillet positions which were taught with the lecture method (control group) obtained the highest score of 81, lowest score of 77, and the mean amounted to 78,5 ; (3) there were differences in learning achievement of students in grade XI SMK N Sukamaju manual arc welding subject of horizontal fillet connections which were taught by demonstration method with taught by lecture method. The differences shown by mean value of experiment group (84,21) was higher than the mean value of control group (78,5)

Study of gas-tungsten-arc welding power density Final report, 1 Jun. 1968 - 30 May 1969

Power density in gas tungsten arc welding with modified cathode