Isothermal compression tests of BSTMUF601 super-alloy in the temperature range of 950˝C-1200˝C and at the strain rates of 0.2 s´1, 5 s´1, 10 s´1 were performed on a Gleeble-1500D thermo-mechanical simulator. Based on the hyperbolic sine function, the unified constitutive equations and hot processing maps during the hot deformation process were established. The flow stress predicted by the constitutive equations shows good agreement with the corrected stress. Hot processing maps for hot working conditions were established based on exploring the effect of power dissipation efficiency and the instability coefficient associated with various kinds of temperatures and stain rates. Subsequently, power dissipation efficiency and the instability coefficient were interpreted based on hot processing maps under a series of strains, temperatures and strain rates. The results show that power dissipation efficiency increases gradually with the increasing temperature and the decreasing stain rate, and instability domains reduce first, then increase with the increase of true strain. The optimum hot working condition of BSTMUF601 super-alloy was obtained.

No abstract