The dynamic recrystallization of steel 321 (/% : 0. 028C

0. 69Si

1. 21Mn

0. 030P

0. 001S

17. 33Cr

9. 19Ni

0. 31Ti) has been studied by single pass hot compression with 0. 01 ~ 1 s

-1

at 900 ~ 1 200 ℃ oh a Gleeble-1500 thermal simulation machine. Results show that with higher deformation temperature and lower strain rate

the softening effect of steel 321 is stronger； generally there is no obvious peak stress at hot deformation true stress-true strain curves ； with strain rate 0. 01

0. 1 and Is-1

the temperature of initial dynamic recrystallization for steel 321 is respectively 1 050 °C

1 150 ℃ and 1 150 ℃，and as deforming at 1 200

℃

the partial dynamic recrystallization only occurs in steel. The activation energy Q for dynamic recrystallization in hot deformation process of

steel 321 is 422. 72 kJ/mol

the dynamic recrystallization Z parameter is εexp[422 720/ (RT)

]

and critical strain ε

c

=0.035 67Z

0.066 04

.