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Measurement and Estimation of Weld Pool Surface Depth and Weld Penetration in Pulsed Gas Metal Arc Welding
| Content Provider | Semantic Scholar |
|---|---|
| Author | Wang, Zuo Gui Zhang, Yi Men |
| Copyright Year | 2010 |
| Abstract | Gas metal arc welding (GMAW) can be considered the most widely used arc welding process, preferred for its versatility, speed, and easy application in robotic automation. Pulsed GMAW (GMAW-P) is used to achieve a controlled metal transfer process over wide ranges of heat and mass input levels (Refs. 1, 2). It uses a low amperage to maintain the arc and a peak amperage to melt the welding wire and detach the resultant droplet. As a result, the desired spray transfer can be achieved at low average currents (Refs. 3, 4). Weld penetration plays a fundamental role in determining the mechanical strength of welds, and thus, its control is critical. This study concerns partial penetration applications where the base metal is not fully melted through its entire thickness. For partial penetration applications, how deep the base metal is melted is referred to as the depth of weld penetration. This depth is often used as the measurement of the weld penetration. It is apparent that the depth of weld penetration is not directly visible. Many methods have been introduced to estimate it based on indirect measurements such as geometrical parameters of the weld pool (Ref. 5), temperature field (Ref. 6), oscillation frequency (Refs. 7, 8), and arc voltage (Ref. 9). To obtain indirect measurements, various techniques such as vision (Refs. 5, 10), ultrasonic (Ref. 11), acoustic emission (Ref. 12), and thermal (Ref. 6) have been used. However, most of those efforts focused on gas tungsten arc welding (GTAW). The GTAW process is less complex and much more stable in comparison with GMAW, which is the concern in this study. The GMAW process uses a consumable wire as an electrode to improve the productivity, and the resultant metal transfer of the melted wire complicates the process. Because of the metal transfer, the droplets impact the liquid weld pool periodically and cause the weld pool to fluctuate. For the pulsed GMAW studied in this paper, the arc pressure also changes periodically, resulting in significant fluctuation in the weld pool surface. The resultant complexity added additional difficulties to obtain indirect measurements needed to estimate the weld penetration. Among the possible indirect measurements, the weld pool surface appears to be the most promising one with sufficient information to estimate the weld penetration. This is because many skilled welders SUPPLEMENT TO THE WELDING JOURNAL, JUNE 2010 Sponsored by the American Welding Society and the Welding Research Council |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | https://app.aws.org/wj/supplement/wj0610-117.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
