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A finite element model is developed to calculate the heat propagation of a circular thin-walled component fabricated in gas metal arc welding based additive manufacturing. The heat evolution, thermal cycle feature, and temperature gradient in molten pool and deposited layers are revealed. The temperature simulations at some locations are in agreement with measured values from thermocouples. As the deposition process proceeds, the high-temperature regions of the substrate and molten pool increase. The temperature gradient in the molten pool decreases with the increasing deposition height. The heat dissipation condition in the molten pool of current layer tightly depends on the deposition direction of fore layer. At the deposition ending moment, the heat conduction in the axial direction is the predominant heat dissipation orientation, whereas the circumferential orientation becomes the main heat dissipation direction in the top layers.

Fabricating geometrical-feature parts using gas metal arc welding (GMAW) additive manufacturing with flat position deposition free from a turn table are proposed through deposition of inclined thin-walled components. During the fabrication process, the torch direction was always maintained perpendicular to the substrate. The definition of inclination angle was presented. Forces of a force model for a pending molten pool were analyzed. Influences of offset distance, wire feed rate, and travel speed on the inclination angle were revealed and discussed. The maximum inclination angle increases along with the travel speed and decreases along with the wire feed rate. A 104-layered cylindrical thin-walled part with geometrical features was fabricated by the proposed approach. Possible sources of fabrication error were presented.