FGH96合金双道次热变形及其热加工图

采用 Gleeble-1500热模拟试验机对 FGH96合金进行双道次真应变量为0.6+0.6和0.3+0.9的等温间断热压缩试验，研究了变形温度为1050~1125℃、变形速率为0.001~0.1 s -1时合金的热变形行为和组织演变.热变形过程中合金发生了再结晶，第一道次较小的真应变量减轻了合金的开裂.当第一道次真应变量小时，随着温度和变形速率的上升，合金道次间再结晶软化率增加.不同应变量以及不同道次真应变量均对合金热加工图产生明显影响.在相同变形条件下，当能量耗散率随应变量的增加而下降时，合金中组织由细晶向粗晶转变，反之则由粗晶向细晶转变；当能量耗散率不随应变量的变化而变化时，能量耗散率低于20%的合金中出现大量的不完全再结晶组织，能量耗散率高于35%的合金中出现细小完全再结晶组织.

Flow behavior and processing map of FGH96 superalloy during two-pass hot deformation

Isothermal interrupted hot compression tests of FGH96 superalloy at the two-pass strains of 0. 6 + 0. 6 and 0. 3 + 0. 9 were performed on a Gleeble- 1500 thermo-mechanical simulator. The hot deformation behavior and microstructural evolution of the su-peralloy were investigated in the deformation temperature range of 1050 to 1125 ℃ and the strain rate range of 0. 001 to 0. 1 s - 1 . It is found that recrystallization happens during the two-pass hot deformation, and less deformation in the first pass results in less cracks in samples. As the first-pass hot deformation is less, the recrystallization degree increases during the deformation gap with increasing de-formation temperature and strain rate. An obviously change is found in the processing map with different strains or different two-pass strains. Under the same deformation condition, when the energy dissipation rate changes with strain, different microstructural evolution rules happen. When the energy dissipation rate decreases with increasing strain, the recrystallization grains coarsen; otherwise, the re-crystallization grains refine. But when the energy dissipation rate does not change with strain, coarse grains appear with the energy dis-sipation rate lower than 20% or a fine grain microstructure appears with the energy dissipation rate higher than 35% .