11
Analysis and Discussion of Data Result 1.
Chemical Composition Tests
Table 1. The data results chemical composition test
Discussion of the Chemical Composition Test Results
From the research results of the chemical composition test carried out,
based on the percentage of carbon element, the steel including low carbon steel, it
contains 0.2 C, by the ASM Committee on metallographic of plate, tube and pipe
steel, this material is included in the category of ASTM and AISI tube steels
A254class I or ASTM and API pipe steels A381 class Y52. Which the chemical
composition, according to ASTM and AISI tube steels A254class I contains 0.05-
0.15 C, 0.27-0.63Mn, 0.050 max P, 0.060 max S. whereas according to ASTM and
API pipe steels A381 class Y52 contains 0.26 max C, 1.40 max Mn, 0.040 max P,
0.05 max S.
2. Hardness test
Table 2. The data results of hardness test of raw material without annealing
Point 1
2 3
Diagonal 1 mm
0.52 0.52
0.52 Diagonal 2
mm 0.52
0.52 0.52
Table 3. The data results of hardness test of annealing material
Point 1
2 3
Diagonal 1 mm
0.52 0.52
0.52 Diagonal 2
mm 0.52
0.52 0.52
Point 1
2 3
Average diagonal
mm 0.77
0.78 0.78
VHN kgmm
2
93.81 91.42
91.42 No
Element Name
Levels of elements
1 Fe
99.2349 2
C 0.0945
3 Si
0.1520 4
Mn 0.3444
5 P
0.0208 6
S 0.0257
7 Ni
0.0255 8
Cr 0.0506
9 Mo
0.0008 10
Cu 0.0345
11 Al
0.0002 12
N 0.0186
13 V
0.002 14
W 0.0016
15 Ti
0.0010 Point
1 2
3 Average
diagonal mm
0.52 0.52
0.52 VHN
kgmm
2
205.69 206.5
205.6
12
Figure 8.Histogram average hardness test value
Discussion of Hardness Test Results
From the test results data using a Vickers hardness tester, it can be seen that
the value of hardness is owned by low carbon steel ASTM and AISI tube steels
A254 class or I ASTM and API pipe steels A381 class Y52 prior to heat treatment,
has high hardness which is equal to 205.6 HVN, but after heated by annealing the
steel hardness being dropped drastically, amounting to 92.21 HVN. This is caused
by grain size changes in the steel after annealing.
3. Tensile Test
Table 3. The data result of tensile test
Figure 9.Histogram average tensile test value
Figure 10. Tensile stress graph
Discussion of Tensile Test Results
From the tensile strength test data,
for test
specimen before
annealing process, the ultimate tensile strength values on average, which is
equal to 526.69 Nmm
2
, and from these data, indicate that the material before
annealing has a higher tensile strength than the material after annealing, with
an average of 389.16 Nmm
2
. As well as the steel yield stress, where the
specimen before annealing had an average yield strength higher is equal
to 471.25 Nmm
2
while steel after annealing has a yield stress, the
amount of 243.75 Nmm
2
.
205.69
92.21 50
100 150
200 250
Raw m at erial annealing
v ic
k e
rs h
a rd
n e
ss v
a lu
e H
V N
56.18 39.76
10 20
30 40
50 60
Raw m at erial annealing
T e
n si
le st
re ss
K g
m m
2
47.59 56.18
24.61 47.59
10 20
30 40
50 60
10 20
30 raw
m at e rial
anne aling
te n
si le
st re
ss K
g m
m
2
elongat ion
Raw D
mm
y
Kgmm
2 u
Kgmm
2
1 8
47.47 53.27
11.67 2
8 45.70
50.12 8.33
3 8
49.61 56.18
10 Annealing
material D mm
y
Kgm m
2 u
Kg mm
2
1 8
24.49 39.51 23.33
2 8
24.99 38.63 21.66
3 8
23.36 39.31 28.33
13
4. Fatigue Rotary Bending Test
