Hot compression tests of DIN 1. 2738 die steel for plastic (/% ：0. 35 ~0. 46C

0

20 ~ 0.40Si

1.30 ~ 1.60Mn

L 80 ~2.20Cr

0.90 ~ 1.20Ni

0.15 ~0.23Mo) are carried out by a Gleeble-3800 thermal-mechanical simulator to get stress-strain curves of steel at 850 ~ 1250℃  with strain rate 0. 01 ~30 s

-1

. Based on the hot deformation data

the peak stresses of steel

the strain-compensated constitutive equation and hot processing maps are established. Suitable hot deformation parameters are also identified by analyzing the processing maps. The results show that the hot deformation activation energy of DIN 1.2738 steel is 354. 21 kj/mol. Adopting the established strain-compensated constitutive equation

the flow curve can be predi

cted accurately. The suitable hot deformation parameters for DIN 1.2738 steel are： (1) temperature between 950 ℃ and 1150 ℃，strain rate between 0.01 s

-1

and 0.7 s

-1

(2) temperature between 1170℃. and 1200 ℃

strain rate between 0. 01 s

-1

and 1 s

-1

.