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Applications in Automobile Industries
Published in S. S. Nandhini, M. Karthiga, S. B. Goyal, Computational Intelligence in Robotics and Automation, 2023
G. Sathish Kumar, D. Prabha Devi, R. Ramya, P. Rajesh Kanna
Robotic welding is used for resistance spot welding along with arc welding. Spot welding is a type of electric resistance welding where two metal sheet products are joined by the heat which is obtained through the resistance to the electric current. These mobile robots are used in automotive industry which involves a high level of production applications.
Heating Systems
Published in Dale R. Patrick, Stephen W. Fardo, Brian W. Fardo, Electrical Power Systems Technology, 2021
Dale R. Patrick, Stephen W. Fardo, Brian W. Fardo
Several familiar welding methods, such as spot welding, seam welding, and butt welding, are resistance welding processes. All of these processes rely upon the resistance-heating principle. Spot welding, illustrated in Figure 12-5A, is performed on overlapping sheets of metal, which are usually less than 1/4-inch thick. The metal sheets are clamped between two electrodes, and an electrical current is passed through the electrodes and metal sheets. The current causes the metals to fuse together. The instantaneous current through the electrodes is usually in excess of 5000 amperes, while the voltage between the electrodes is less than 2 volts.
Joining Technologies
Published in Raghu Echempati, Primer on Automotive Lightweighting Technologies, 2021
Resistance spot welding is a process that utilizes the heat obtained by the resistance to the flow of electric current to the workpieces through electrodes that concentrate current and pressure to the weld area. The generated heat is used to melt and solidify a nugget at the faying surfaces of a joint.
Development of numerical model in ring mash welding
Published in Welding International, 2023
Yasuo Kadoya, Yuki Oshino, Hironobu Nishimura, Fumiaki Toyama, Satoshi Yamane
Spot welding is widely used for welding thin steel sheets in automobiles k [11–13]. In this welding process, a thin steel plate is clamped between upper and lower electrodes, pressure is applied, and then a large current is applied for a short time. The contact resistance between the electrodes and the steel plate is reduced by the application of pressure. The contact resistance between the steel plates then generates Joule heating due to the large current flow. This heat generates a molten area (nugget) at the centre between the steel plates and joining takes place. Thus, by energizing the welding current, it is possible to use the temperature rise of the steel plate itself due to Joule heat. There is also projection welding, in which a nut or the like is joined to a steel plate [14]. The joining area is larger than that of spot welding. In principle, as in spot welding, after applying pressure, a large current is applied to melt the joint between the nut and the steel plate. Since the contact area of the nut and other parts is larger than the contact area between the electrode and base metal in spot welding, it is necessary to increase the current density when energizing to obtain the Joule heat necessary for melting, and the current is higher than in spot welding [14].
Particle simulation of nugget formation process during steel/aluminum alloy dissimilar resistance spot welding and thickness estimation of intermetallic compounds
Published in Welding International, 2022
Shinnosuke Chikuchi, Masaya Shigeta, Hisaya Komen, Manabu Tanaka
Resistance spot welding is a welding method in which overlapped materials are sandwiched between electrodes and energized while applying pressure to form a molten part (nugget) between the materials to be welded by Joule heating to join the materials. Compared with other welding methods, resistance spot welding is widely used in mass production technology for automobiles, railcars and electrical appliances because of its short welding time and ease of automation. In particular, resistance spot welding is used for 3,000 to 6,000 joints in the assembly of automobile bodies [1]. In recent years, environmental measures and the increasing demand for lighter car bodies due to the electrification of automobiles have made it urgent to establish a technology for resistance spot welding of dissimilar materials between steel and aluminum alloys, which are lightweight metals [2,3]. However, it is known that when steel and aluminum alloys are welded, a layer of brittle intermetallic compound (IMC: Intermetallic compound) is formed at the joint interface, which reduces the strength of the joint [3]. To prevent this, research is being conducted to control the intermetallic compound layer formed at the joint interface in resistance spot welding of steel and aluminum alloys with dissimilar materials.
Investigation of relationship between resistance spot welding condition and nugget shape by utilizing machine learning based technique
Published in Welding International, 2019
Houichi Kitano, Akira Sato, Muneyoshi Iyota, Terumi Nakamura
Resistance spot welding is a method in which an electric current is passed through two or more plates and the plates are melted by generated resistance heating and joined. The advantages of resistance spot welding are that high-speed joining is possible and robot-based automation is comparatively easy. Because of this, it is used in the fabrication of a range of structures principally in motor vehicle body construction processes. One major factor determining the strength characteristics of resistance spot welded joints is the molten zone shape, in particular the molten zone diameter (nugget diameter). Representative values for strength of a resistance spot welded joint include tensile shear strength (TSS) and cross tension strength (CTS) but it is known that all types of strength are affected by nugget size so it has been proposed [1–4] that, although there are differences due to fracture mode, TSS and CTS are proportional to nugget diameter or the cross-sectional area of the molten zone between the plates, as in the empirical formula (= π{(nugget diameter)/2}2).