Temperature field simulation of the molten pool in SEAM

Abstract

Short electric arc machining (SEAM) technology is a complex process involving arc physics, heat and mass transfer, metal melting, and solidification, which is characterized by locality, instantaneity, and unsteady states. The energy distribution as well as both the shape and size of the molten pool has an important influence on the quality of surfaces machined with SEAM. This paper presented a mathematical model of the short electric arc molten pool built via scientific method to conduct a quantitative analysis of the heat transfer of the molten pool. The model was conducted via discretization based on ANSYS and obtained change pattern of the quasi-steady state temperature field in the short electric arc molten pool via solving the set up mathematical model. Furthermore, the short electric arc discharge removal process was simulated via element birth and death technology. The temperature increase in SEAM was monitored with the A40 infrared thermal image instrument, the thermal cycling curves of the three critical nodes were analyzed, and the result shows that the maximum error between the simulated and the actual values was smaller. This verified that the setup model and adopted software method are appropriate and feasible. The surface microstructure of the nickel-based super-alloy GH4169 shows that the strong thermal effect of the arc in the molten pool causes the material near the eroded zone to instantaneously reach the melting point, and cool rapidly. This resulted in a strong temperature gradient, which had a significant effect on the microstructure, properties, and residual stress of the erosion zone.