Single-Pass Process of Square Butt Joints without Edge Preparation Using Hot-Wire Gas Metal Arc Welding

Abstract

This paper presents a novel approach to welding thick steel plates that offers time and energy savings compared with conventional techniques. The combination of gas metal arc welding (GMAW) and hot-wire technology simplifies the joint configuration and enhances the process tolerance. In this study, a square butt joint was prepared with as-cut edges and a thickness of 15 mm. The relationship between the welding current and the deposition rate of solo GMAW showed limitations and low process tolerance. Increasing the welding current led to a larger deposited volume with unnecessary weld penetration. An independent deposition volume due to hot-wire insertion was used to improve process tolerance. This approach provided an additional volume without increasing the welding current and reduced unnecessary penetration. With optimized parameters, full-penetration single-pass welding was achieved. Compared with the formation of a typical single-v butt joint at a similar welding speed of 30 cm/min, the proposed process reduced the minimum arc time and power consumption by approximately 83% and 62%, respectively. Moreover, a single pass at a travel speed of 60 cm/min was achieved with approximately 91% and 81% less arc time and power consumption, respectively. In summary, the combined process simplifies the joint configuration, enables full-penetration single-pass welding, and reduces time and energy requirements.

Optimization of hot-wire fraction for enhance quality in GMAW

“…This phenomenon, known as molten metal precedence, has been reported under excessive total deposition volume conditions [25,26]. Bead appearance at the 54.15% HW condition showed a humping bead, which is obvious evidence of molten metal precedence [24][25][26]. Moreover, lack of fusion was unexpectedly observed at 49.60% HW, where molten metal precedence was not detected by the high-speed camera during hot-wire GMAW, as shown in Figure 8(d).…”

“…However, the yellow bars in Figure 5 indicate that a similar effective height could be achieved with hot wire at the same deposition rate. A recent study [24] defined the shallower penetration as a lifting effect when the hot wire was applied. Effects of hot-wire parameters on weld geometry were reported by Tsuyama et al [23] and Wonthaisong et al [25].…”

“…In addition, Tsuyama et al [23] proposed combined hot-wire GMAW, which can provide a similar deposition volume to SAW. With the resulting high deposition volume, a successful single-pass weld of a 15-mm thick steel butt joint was achieved out without edge preparation at 0.6 m/min travel speed [24]. Optimization of the hotwire fraction was also studied by Wonthaisong et al [25] to achieve a single-V butt joint of a 20-mm thick steel plate with increased weld metal hardness.…”

Selection of Welding Conditions for Achieving Both a High Efficiency and Low Heat Input for Hot-Wire Gas Metal Arc Welding

“…Welding processes that involve a hybridization of the hot-wire method (e.g., gas tungsten arc welding (GTAW), GMAW, submerged arc welding, laser welding) have been investigated and applied to improve productivity in fields beyond the construction machinery industry [11][12][13][14][15][16][17][18][19][20][21][22]. The welding phenomena and optimization of hot-wire feeding conditions have been investigated for the GTAW process [23].…”