from the conferences organized by TANGER Ltd.
Nickel-chromium alloys are increasingly used in constructions of the most loaded machine components including aircraft engines. Therefore, determining the parameters of metal forming for those alloys is very important. The hot deformation behaviour of Ni55Cr45 alloy with cast starting structure was investigated in the temperature range of 750–1150 °C and strain rate range of 1–100 s-1. The workability consists of two parts: the intrinsic workability and the State-of-Stress (SoS) workability. Processing maps showing the intrinsic workability dependent on material properties have been drawn on the basis of experimental data from compression tests carried out on a Gleeble 3800 thermomechanical simulator and based on the Prasad's approach. Due to the significant influence of strain on the efficiency of power dissipation parameter and the instability parameter , maps were drawn for a true strain in a range of 0.1–0.9. The processing windows and the flow instability regions have been determined. By using Lua scripts processing maps have been integrated with the commercial software based upon FEM – QForm V8 for numerical calculation, which made possible to designate the distribution of the flow instability parameter during forging. In addition, the strain rate sensitivity parameter m and the efficiency of power dissipation parameter for the investigated forgings have been determined. Such approach has allowed to integrate the intrinsic workability and the State-of-Stress workability and showed that it can be considered as an effective method of workability analysis.
Keywords: Ni55Cr45, processing maps, workability, State-of-Stress© This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.