Experimental
The composition of the steel used for the experiments is shown in Table
1, along with its ortho-equilibrium and para-equilibrium
Ae3 temperatures. These values were calculated using the
FactSage thermodynamic software, employing the FSStel Database®
[13]. Materials were provided by Finkl Steel-Sorel, Canada.
Cylindrical specimens were machined from the central region of the
as-cast ingot with diameters and heights of 10 mm and 15 mm,
respectively. Hot compression tests were performed using a Gleeble 3800®
thermomechanical simulator following the procedures described in ASTM
E209. The schematic diagram for double-hit compression tests is shown in
Fig. 1. Two temperatures
(1200
°C and 1150 °C), two strain rates (0.25 s-1 and
0.5 s-1), and one interpass time (5 s) were employed
in the experiments.
Table 1: Composition of
medium-carbon low-alloy
steel.