Civil Engineering Reference
In-Depth Information
Table 4.1
Specimen dimensions [
5
]
Def. level
Diameter (mm)
Height (mm)
L
0
3.81
5.72
4.32
4.45
L
1
5.11
3.18
L
2
of the “as-is” specimens, the current density supplied to the workpieces is about
26 A/mm
2
, which is above the threshold current density of about 20 A/mm
2
deter-
mined by Perkins et al. [
2
].
Two types of tests were performed in this work. First, deformation tests were
run, where the specimens were deformed at a constant die speed from an ini-
tial height of L
0
to deformation levels of L
1
or L
2
, with and without electricity
applied (note: electricity applied at 300 A). Stress-strain and thermal profiles
were created from these tests. Second, stationary electrical tests were per-
formed, where electricity was applied to a specimen without plastic deforma-
tion. In particular, the dies were in contact with the specimen such to prevent
hot spots at the contact interfaces and to allow electricity to flow, but without
causing plastic deformation in the sample. Thermal profiles were gathered from
these tests and were used in comparison with each other and with the thermal
profiles from the deformation tests, as will be shown in the following sections.
The different test combinations and corresponding specifications can be seen in
Table
4.2
.
Table 4.2
Test combinations and specifications [
5
]
Grade
Deformed/Stationary
EAF/Conv.
Displ.
Prev. structure
%CW
Def.
EAF
L
0
-L
2
As-Is
-
2
2
Def.
Conv.
L
0
-L
2
As-Is
-
Def.
EAF
L
0
-L
2
As-Is
-
5
Def.
Conv.
L
0
-L
2
As-Is
-
5
2
Def.
EAF
L
1
-L
2
Init. Def. to L
1
22
Def.
Conv.
L
1
-L
2
Init. Def. to L
1
22
2
Def.
EAF
L
1
-L
2
Init. mach. to L
1
-
2
2
Def.
Conv.
L
1
-L
2
Init. mach. to L
1
-
Stationary
EAF
L
1
Init. Def. to L
1
22
2
2
Stationary
EAF
L
1
Init. mach. to L
1
-
2
Stationary
EAF
L
2
Init. Def. to L
2
44
Stationary
EAF
L
2
Init. mach. to L
2
-
2
5
Stationary
EAF
L
1
Init. Def. to L
1
22
5
Stationary
EAF
L
1
Init. mach. to L
1
-
Stationary
EAF
L
2
Init. Def. to L
2
44
5
5
Stationary
EAF
L
2
Init. mach. to L
2
-
