Effects of torch configuration and welding current on weld bead formation in high speed tandem pulsed gas metal arc welding of steel sheets

Abstract

Undercut and humping bead are the common defects that limit the maximum welding speed of tandem pulsed gas metal arc (GMA) welding. In order to increase the maximum welding speed, effects of the inclination angle, interwire distance and welding current ratio between the leading wire and trailing wire on bead formation in high speed welding are investigated. The undercut and humping bead is attributed to the irregular flow of molten metal towards the rear part of the weld pool. This irregular flow can be prevented by the trailing wire with a push angle from 5° to 13°, which provides an appropriate component of arc force in the welding direction. The irregular flow is also related to the distance between the leading wire and the trailing wire, and the flow becomes regular when the distance is in the range 9–12 mm. Moreover, the stabilisation of the bulge of the weld pool between the two wires, the presence of enough molten metal below the trailing arc, and the reduced velocity of molten metal flow towards the rear part of the weld pool, are essential to increase the maximum welding speed. These conditions can be obtained by adjusting the ratio of the leading arc current to the trailing arc current. A maximum welding speed as high as 4–4·5 m min−1 is achieved by setting the current ratio to a value ranging from 0·31 to 0·5.

Observation and Control of Keyhole in Robotic Plasma Welding

“…However, there are the following problems in the practical field of welding. Automation of the welding with high efficiency and a high quality are required due to the globalization of the field of manufacturing, and the decrease of the welding engineer 1) . In the CO 2 welding, spatter and fume occur.…”

Effects of filling status of cold wire on the welding process stability in twin-arc integrated cold wire hybrid welding

“…Taking gas metal arc welding (GMAW), for example, a great deal of research efforts that are mainly in respect of multi-wire arc welding equipped with single or several welding power sources were carried out [2][3][4]. Corresponding welding technologies were developed, e.g., tandem twin-wire welding [5][6][7], consumable doubleelectrode GMA welding [8][9][10][11], hybrid laser double GMA welding [12][13][14], etc.…”

Analysis of arc interference and welding stability in twin wire GMA welding

“…The result showed that the resistance to arc extinction was increased as the arcing current was also increased. For now, some prevalent methods to reduce the arc interference are listed as follows: (1) adjusting the distance between welding wires and the angle of welding torch [4], (2) adjusting the ratio of gas and current [5], and (3) using pulse coordination control [6].…”