FEM simulation of open die forging of a plate from material NIMONIC 80A in DEFORM 3D

摘要

This article presents results of a three-dimensional FEM-simulation of open die forging of a plate from material NIMONIC 80A. The FEM-simulation was carried out in DEFORM 3D Multiple Operation. The open die forging simulation contains many sequence operations, each single stroke and displacement of dies had to be modelled. The FEM-simulation of the open die forging process was set in accordance with real process conditions. The plastic behaviour of material NIMONIC 80A was defined by means of strain hardening data which was obtained on the basis of measured data from Rastegaev compression test. The desired final thickness of the plate was reached by two procedures to study the effect of an amount of a reduction. The first procedure comprised 8 reduction passes with three reheatings, and second procedure comprised 10 reduction passes with four reheatings. The data evaluation of crack initiation in the FEM-simulation was carried out by tensile tests on the specimens. The main effect on the crack initiation was the decrease in temperature on a edge of the plate. The real forgings show transverse cracks on the surface which starts on edges of the plate during forging. A good agreement between the simulation and experiment results was observed.