Hot Deformation Behavior,Microstructure,and Processing Map of Nb-1OZr Alloy
To elucidate the hot deformation behavior of Nb-10Zr alloy,thermal simulation compression tests were conducted using a Gleeble-1500 thermal simulation testing machine.The effects of deformation parameters such as deformation degree,deformation temperature,and strain rate on the microstructure and processability of Nb-10Zr alloy were systematically investigated,the stability regions and instability regions of the flow with various temperatures and strain sates were analyzed,the processing maps based on a dynamic material model were established for designing and improveing materials processing.Through analysis of experimental data,such as the strain rate sensitivity of the flow stress,the power dissipation efficiency ηand the instability parameter ξ,the deformation window of the alloy was clarified,and the accuracy of the processing map was analyzed and verified through microstructure.The results showed that:the Nb-10Zr ingot which melted by vacuum consumable electro-arc furnace,was suffered the homogenization treatment at 1 300 ℃ for 24 h.The composition segregation and other defects could not be found in the ingot.There are coarse and fine microstructures in the ingot,and its grain sizes are 500-800 μm and 20-30 μm separately;Under 0.4 and 0.6 strain conditions,there are two reasonable hot working windows for the Nb-10Zr alloy:deformation temperature range of 1 060 to 1 100 ℃ and the deformation rate range of 0.01 to 0.04 s-1;deformation temperature range of 1 080 to 1 100 ℃ and the deformation rate range of 0.3 to 1 s-1.Under the above deformation conditions,the Nb-10Zr exhibits fine dynamic recrystallized microstructures.For instance,the grain size is 80-100 μm at 1 100 ℃ and 0.01 s-1;and the grain size is 40-60 μm at 1 100 ℃ and 1 s-1.The results were confirmed the rationality of the determined processing window.The research was provided the theory instruction for follow-on production.
Nb-10Zr alloyhot compressionprocessing mapmicrostructurehigh temperature deformationworking propertydynamic material model
NETL
NSTL
万方数据
维普
