Study on hot deformation behavior and numerical simulation for hot extrusion process of corrosion resistant 825 alloy

The hot deformation behavior and microstructure evolution of a corrosion resistant Fe-Ni base superalloy named as Alloy 825 were investigated by means of hot physical simulation on Gleeble-1500. The properties of flow curves were analyzed, and constitutive equation for 825 alloy was established. Then optical microscope was used to analyze dynamic recrystallization (DRX) behavior during hot working process. A finite element software MSC. Superform was used to simulate the hot extrusion process of typical pipes for this alloy. The results showed that extrusion speed and billet temperature were the main factors to influence the hot extrusion deforming resistance, and the acceptable extrusion parameters for Alloy 825 may be in the range of 1100 degrees C-250mm/s, 1150 degrees C-200mm/s, 1150 degrees C-250mm/s, 1200 degrees C-150mm/sand 1200 degrees C-200mm/s. The simulation results can be the reference for extrusion process design of this alloy. (C) 2011 Published by Elsevier Ltd.