Study of Effects of Variations in Process Parameters on the Extrusion Process by Use of Finite Element Simulations

摘要

There is a significant demand to reduce variations in shape and mechanical properties of extruded sections. Variations in flow and temperature evolution during the extrusion process are some of the sources to such variations. In this work, axi-symmetric finite element simulations of a generic case with two exits at different radial positions have been performed to study how variations in process parameters influence variations in exit speed and exit temperature. The effects of variations in ram speed, billet temperature, initial billet temperature gradient (taper), and container cooling have been studied. For each set of process parameters the simulations have been done over 20 press cycles with two different finite element software Two types of variations have been studied. The first involved variations in flow balance or differences in exit velocity and temperature between the two exits. The second involved variations in the average exit temperature over the press cycle, with the aim of detennining conditions for isothermal extrusion. Effects of each of the process parameters on flow balance, temperature evolution, and conditions for isothermal extrusion have been presented and discussed.