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A three-dimensional numerical model of arc in gas metal arc welding (GMAW) with single cable-typed wire was established based on the theory of arc physics. The influences of different shielding gas flow rates on the features of temperature field, velocity field and pressure field were investigated. The results showed that the maximum velocity of arc plasma along radial direction and the arc pressure on the surface of workpieces were increased obviously with the increase of the shielding gas flow rate, while the arc temperature was changed little. This phenomenon was mainly attributed to the increasing collisions between arc plasmas and the self-rotation action of cable-typed wires. The arc temperature at the tip of the cable-typed wire reached the maximum. The maximum flow velocity of arc plasma was located at the tip of wire (2–8 mm). The arc pressures in the central axis reached the maximum pressure. The simulation results were in agreement with the experimental results.

The assisted wire filling (AWF) cable-type welding wire (CWW) gas metal arc welding (GMAW) is an innovative welding process in which the wire of CWW GMAW is used as the electrode, and the assisted wire using the arc and molten pool melt. The electrode and assisted wire are with CWW, composed of seven wires, one in the center and others uniformly distributed around it. This paper compares the weld seam appearance, arc shape, arc behavior, electrical parameters, and deposition characteristics of the AWF CWW GMAW and CWW GMAW. The arc shape and electrical parameters of AWF CWW GMAW are similar to the CWW GMAW, in which the welding process was not disturbed by the assisted wire. The AWF CWW GMAW welding wire melting and metal deposition rates are higher than those for CWW GMAW with the same welding parameters. The regular changes of weld width, weld depth, and reinforcement that increased with the increase of welding current are the same as those of the welding seam from CWW GMAW. The AWF CWW GMAW weld depth decreased, and the reinforcement is increased compared with the CWW GMAW under the same current. The tension test of the AWF CWW GMAW button joint meets the requirements of CCS.

Surfacing technology is widely used in material surface modification and repair industries, with the advantages of low dilution rate and high wear-resistance performance. The assisted wire filling (AWF) of cable-type welding wire (CWW) gas metal arc welding (GMAW) is an innovative surfacing method, using CWW as the consumable electrode. The dilution rate and wear-resistance performance were studied in this paper. The results show that the weld penetration of the AWF-CWW-GMAW surfacing layer increased with the increase of welding current, which was consistent with the method of CWW GMAW. The dilution rate of the surfacing layer was about 19% lower than that of the CWW-GMAW with the same parameters. Comparing with the CWW-GAMW method, the sample treated by AFW-CWW-GAMW had a smaller dilution rate of surfacing layer, a less wear loss, a smaller friction coefficient and a higher hardness under the same welding parameters. The alloy element distribution of the surfacing layer was higher than that of CWW-GMAW from the weld to the base metal.

The cable-type welding wire gas (CWW) metal arc welding (GMAW) is an innovative arc welding process with high efficiency and high welding quality. However, there is still a lack of deep research on the molten pool of CWW-GMAW. The behavior of molten pool of CWW-GMAW was studied by both numerical simulations and experiments. The temperature field and flow field in the longitudinal section and across cross-section under the current of 450 A in CWW-GMAW were simulated. The result shows that the isotherm in front of the molten pool is denser than that in the back on the longitudinal section. The arc rotation force causes the velocity of the molten pool in the direction of weld penetration becoming more significant than that of weld width. The rotating momentum of the droplet affects the temperature distribution of the weld width and penetration on the cross-section of the molten pool. The coupling of electromagnetic force and rotating arc force makes the flow field present a clockwise vortex shape. The simulated results of weld geometries of CWW GMAW are in good agreement with the experimental results, indicating the applicability and accuracy of the established model.

By establishing a three-dimensional (3D) numerical simulation of the Ti-6Al-4V Gas Metal Argon Welding (GMAW) molten pool, the molten pool’s heat transfer and fluid flow behavior under a longitudinal magnetic field were investigated. The simulation results show that when the droplet enters the molten pool, the liquid metals on the molten pool’s surface symmetrically flow towards both sides of the molten pool from different angles. With the increase of the magnetic field strengthens, the temperature gradually decreases, and the fluid flow velocity increases continuously. Besides, the magnetic field strength is correlated positively with the molten pool’s size with a certain range of 0–0.03 T. However, when the magnetic field strengthens reach 0.04 T, the magnetic field is correlated negatively with the molten pool’s size. Because the Marangoni and buoyancy begin to weaken, the molten pool’s length change occurs before the width change. Simultaneously, a sizeable velocity region appears on the left side of the molten pool. Thus, the liquid metal gathers on the left side, resulting in the weld cross-section’s asymmetry. It can conclude that only when the magnetic strengthen keeps in the range of 0–0.03 T, the longitudinal magnetic field can make the molten pool’s surface profile smooth.

This study aims to investigate the impact of heat treatment on the microstructure and welding properties of cable-type welding wire gas metal arc welding (GMAW) in shipping steel. In contrast to the untreated weld, the width of the heat-affected zone of the weld after heat treatment decreased. The microstructure of welded joints following heat treatment and air cooling is relatively and finer compared to the grain structure after furnace cooling and without heat treatment. The tensile strength of welded joints decreases compared to that of untreated weld, while it is higher than that of joints after heat treatment and furnace cooling. The impact toughness of heat treatment is higher than that of the weld seam, heat-affected zone, and fusion line without heating treatment, and the impact performance is higher than that of post-weld heat treatment with furnace cooling.

A prevalent method for rapid prototyping of metallic parts is gas metal arc welding (GMAW). As the input parameters impose a highly nonlinear impact on the weld bead geometry, precise estimation of the geometry is a complex problem. Therefore, in this study, a novel combination of the most powerful machine learning algorithms is selected to overcome the complexity of the problem and also reach an acceptable degree of precision. To this end, the hybrid combination of the support vector machine (SVM) and relevance vector machine (RVM) is developed based on the random forest (RF) ensemble learning approach. The models are established based on a global database of welding geometry, and the corresponding process parameters obtained are based on a set of experiments. Performance evaluation between RVM, SVM, and the proposed model was performed based on the coefficient of determination ($R^2$) and the ratio of root means square error (RMSE) to the maximum measured outputs ($\mathrm{\text{RMSE}}$/$y_{\mathrm{\text{max}}}$). The RF-based RVM-SVM model obtained 0.9725 and 0.8850 for $R^2$ and 0.0257 and 0.0447 for $\mathrm{\text{RMSE}}$/$y_{\mathrm{\text{max}}}$ in predicting the height and width of the bead, respectively. The result clearly showed the effectiveness of the proposed model in predicting the GMAW trend.