ISOTHERMAL PLASTIC FORMING OF HIGH-MELTING TEMPERATURE ALLOYS

This paper deals with the problem of an unconventional plastic forming process-deformation of high melting temperature alloys under isotherm al conditions. The test were performed for alloyed steel containing 0. 5% C. The upsetting process at various temperatures and strain rates w as used to determine the optimum parameters of deformation. In order t o obtain fine grains prior to deformation and create the superplastici ty effect, the samples were subjected to thermomechanical processing. The main experiment included axisymmetrical closed-die forging. Very g ood filling of the grove and low loads were observed in all tests. Des pite the relatively long time of deformation at high temperatures, the material maintained a fine microstructure. (C) 1997 Elsevier Science S.A.