The softening behavior of 0.75C-0. 11V microalloy steel isothermal deforming at austenitic area 850~1000 ℃ within interval of passes has been studied by double-pass compression test using Thermecmastor-Z thermal simulation machine.Results indicated that with 30% deformation and 3 s
-1
deforming rate
as deformation temperature ≥1000 ℃
the relaxation time for performing recrystallization was ≤100 s
and as deformation temperature ≤880 ℃
it was diffcult even extending relaxation time to put forward recrystalization of steel.