Research On Thermal Deformation Be-havior And Microstructure Of4Cr5MoSiV1Alloy

In this paper, Gleeble-1500thermal simulation machine was used toresearch the microstructure capacity and behavior of4Cr5MoSiV1alloy. Thetemperature of hot compression test is950～1100℃.Strain rate is0.01～10.0s–1.Maximum engineering strain is20～50%.According to the experimental results, the hot compression microstructuretrue stress-true strain curve of4Cr5MoSiV1alloy was obtained. Microstructuretemperature and strain rate on the influence of the flow stress was studied. Theresults show that the flow stress increased with the increase of microstructurerate when the microstructure temperature is constant, and the flow stressdecreases with increasing temperature when the strain rate is constant. In thebeginning stages of microstructure, flow stress increased rapidly due tohardening. After that, hardening and rheological softening gradually achieve abalance. Typical dynamic response characteristics are presented.The true stress-true strain curve data is used to establish for the thermaldeformation of4Cr5MoSiV1alloy constitutive equation. Experimental resultsshow that the constitutive equations can better describe the rheological behaviorof the alloy. And the constitutive equations ofZ=6.8×1015[s inh(0.00605σ)]6.4is based on the Arrhenius-type hyperbolic sine equation. Under differentmicrostructure conditions, the flow stress is compared with experimental values.In the error analysis, the constitutive equation can be a better responserheological behavior of the4Cr5MoSiV1alloy.In the use of experimental data, the microstructure of4Cr5MoSiV1alloy under different conditions of activation energy diagram and heat processing mapare created basing on Dynamic Materials (DMM) model theory. Through analysisof the activation energy diagram, with the temperature and strain rate increases,the activation energy value gradually decreases, the more easily deformed. In theexperiment temperature is1050~1100℃, and the strain rate range is1~10s-1,4Cr5MoSiV1alloy thermal activation energy is at the lowest level. The region ofthe most easily deformed showed a small platform. Microstructure is the mostlikely to be carried out. Through analysis of the thermal processing, the resultsshow that the energy consumption efficiency4Cr5MoSiV1alloy, η reaching apeak of about25%, when the temperature is1050℃and the strain rate is1~10s-1,or when the temperature is1100℃and the strain rate is0.1s-1.Using optical microscope (OM), the microstructure of4Cr5MoSiV1alloywas observed at different microstructure conditions. The mechanism ofmicrostructure characteristics is revealed. The results show that themicrostructure of the alloy with the increasing of strain rate or deformationtemperature is increased.