machining behavior of en24 and en36c steelsijiet.com/wp-content/uploads/2019/04/4.pdfchip reduction...
TRANSCRIPT
International Journal of Innovations in Engineering and Technology (IJIET)
http://dx.doi.org/10.21172/ijiet.124.04
Volume 12 Issue 4 March 2019 021 ISSN: 2319-1058
Machining Behavior of En24 and En36c Steels
Nikhil Bharat1, Vishal Mishra2, Dr Kalyan Chakraborty3 1,2M.Tech (Mechanical) Student, Department of Mechanical Engineering
National Institute of Technology, Silchar, Assam 3Associate Professor, Department of Mechanical Engineering
National Institute of Technology, Silchar, Assam
Abstract EN24 and EN36C steels are among the steels that are used in dynamic environment and in heavy duty
applications. The paper presents the machinability of EN24 and EN36C steels with reference to turning of the work
materials on lathe using carbide insert. Principal aim of investigation was to know the mechanism of chip formation and
von Mises stress (VMS) generation during machining. Severe plastic deformation occurs in the primary deformation zone
(PDZ) and subsequently chip forms and von Mises stress generates. Cutting velocity, feed and depth of cut (d.o.c) are the
input parameters for machining on work material and chip reduction co-efficient (CRC) and von Mises stress (VMS) are
the output parameters. 33 factorial design of experiment was considered to conduct the experiment. The von Mises stress
(VMS) was determined employing CRC and material properties namely strain hardening exponent ‘n’ and strength co-
efficient ‘K’.
Presence of residual stress on machined item has to be identified as this may cause some detrimental effect on machined
component. Therefore, presence of such stress was identified through XRD study in the present work.
Finally, behavior of chip material during formation was also observed by SEM and EDX examination.
Keywords Chip reduction coefficient (CRC); von Mises stress (VMS); Chip formation mechanism.
I. INTRODUCTION
EN24 and EN36C steels are usually used for production of various mechanical components. These materials are processed extensively by machining. Therefore, present study is aimed at to determine machinability of these
materials. Machining response parameters like tool wear, surface roughness, cutting forces etc are usually
considered for machinability assessment. Induced von Mises stress (VMS) on machined surface can be another
factor to be considered for machinability assessment.
Machining process is based on plastic deformation of work material. Machining chip is formed through plastic
deformation only. Chip reduction coefficient(ξ) can be considered as an index of plastic deformation. Machining
process is very much influenced by deforming behaviour of work material. It is therefore necessary to incorporate
CRC as an index for determination of induced von Mises stress (VMS) on the machined item. Generated von Mises
stress (VMS)on the machined component is also strongly influenced by property of the work material.
Present work illustrates the method for determination of von Mises stress (VMS) based on deformation index (CRC)
and material property namely strength coefficient ‘K’ and strain hardening exponent ‘n’. This method for determination of von Mises stress (VMS) employing ξ, n and K can be considered as most appropriate consideration
since von Mises stress (VMS) generation is directly related toplastic deformation and subsequently to property of
materials. Literature considering this procedure to determine the von Mises stress (VMS) on the machined
component employing ξ, n and K is scarce.
Vishal Mishra et al. [1] performed machining on EN24 and EN36C steels using carbide tool and found that tool
wear takes place through adhesion and chipping while machining EN24 steel. They also observed that for machining
with EN36C steel, tool wear takes place through abrasion.
Vishal Mishra et al. [2] studied the effects of von Mises stress (VMS) generation during Machining on EN36C steel.
It was observed that EN36C steel showed better results during maching at cutting speed: 60m/min, feed:
0.63mm/rev and doc: 1mm.
Geethanjali KS et al. [3] studied the effects of machining on tool forces, power consumption and surface roughness.
It was observed that for EN19 steel and EN24 steel, cutting speed has a significant effect on power. Nikhil Bharat et al. [4] conducted experiment on EN24 steel on lathe using carbide tool and concluded that EN24
steel can be machined at higher speed, feed and depth of cut (d.o.c).
II. EXPERIMENTAL PROCEDURE
In the present study EN24 and EN36C steels are used as work materials having 400mm of length and 110mm of
diameter. Machining was performed on central lathe by using tool insert of coated carbide grade. Table 1 and table 2
show the chemical compostion of work material.
International Journal of Innovations in Engineering and Technology (IJIET)
http://dx.doi.org/10.21172/ijiet.124.04
Volume 12 Issue 4 March 2019 022 ISSN: 2319-1058
Table 1. Chemical composition of EN24 steel
%Fe %C %Mn %Si %P %Cr %Mo %Ni %Al %S
Balanced 0.398 0.582 0.206 0.029 1.04 0.246 1.36 0.0235 0.0164
Table 2. Chemical composition of EN36C steel.
%Fe %C %Mn %Si %P %Cr %Mo %Ni %Al %S
Balanced 0.159 0.386 0.182 0.0164 0.820 0.131 3.10 0.0182 0.0199
Central lathe was employed for machining on the work material which has speed range of 45 rpm to 1000 rpm and
feed range of 0.06 mm/rev to 1.72 mm/rev.
2.1. Tool Specification Holder specification: ASBNR 25*25 M12-A
Holder Specifications Designation System Assigned Values
A Clamping system Double clamping
S Insert shape Square
B Cutting edge style Principle Cutting edge angle=15o
N Relief angle of insert 0o
R Hand of tool Right hand
25*25 Shank size 25mm*25mm(height*width)
M Holder length 150mm
12 Insert size 12mm
A Machining insert Turning
Insert Specification: SNMG 120404 TM T9125
Insert Specifications Designation System Assigned Value
S Insert shape Square with hole
N Relief angle 0o
M Accuracy Tolerance
G Groove Cylindrical hole
12 Cutting edge length 12mm
04 Thickness 4mm
04 Corner radius 4mm
TM Chip breaker symbol TM
T9125 Stocked grade Coated
Cutting speed, feed and depth of cut (d.o.c) are the input process parametrs used for the experimentation. The
experimentation was based on 33 factorial design. Table 3 shows the arrangement of input process parameters with
given level of cutting.
Table 3. Input parameters used for machining.
Factors Level 1
(lowest level)
Level 2
(moderate level)
Level 3
(highest level)
Coding -1 0 1
Speed (m/min) 36 60 100
Feed (mm/rev) 0.49 0.63 0.86
D.O.C (mm) 0.67 1 1.5
International Journal of Innovations in Engineering and Technology (IJIET)
http://dx.doi.org/10.21172/ijiet.124.04
Volume 12 Issue 4 March 2019 023 ISSN: 2319-1058
Formulation for the selection of input process parameter values for the level.
Where,
Code(v,f,d)=values for various codes with reference to speed,feed and d.o.c
(v,f,d)m= cutting speed, feed and doc at moderate level.
(v,f,d)max= cutting speed, feed and doc at highest level.
Based on the above given input process parameters, 33 factorial design of experiment was done which provided 27
different combinations.
Table 4. 33 factorial design is showing the input parameters for machining.
S.No. Assigned Codes Velocity (V)
m/min
Feed (f)
mm/rev
Depth of cut (d)
mm V F d
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
-1
-1
-1
-1
-1
-1
-1
-1
-1
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
1
-1
-1
-1
0
0
0
1
1
1
-1
-1
-1
0
0
0
1
1
1
-1
-1
-1
0
0
0
1
1
1
-1
0
1
-1
0
1
-1
0
1
-1
0
1
-1
0
1
-1
0
1
-1
0
1
-1
0
1
-1
0
1
36
36
36
36
36
36
36
36
36
60
60
60
60
60
60
60
60
60
100
100
100
100
100
100
100
100
100
0.49
0.49
0.49
0.63
0.63
0.63
0.86
0.86
0.86
0.49
0.49
0.49
0.63
0.63
0.63
0.86
0.86
0.86
0.49
0.49
0.49
0.63
0.63
0.63
0.86
0.86
0.86
0.67
1
1.5
0.67
1
1.5
0.67
1
1.5
0.67
1
1.5
0.67
1
1.5
0.67
1
1.5
0.67
1
1.5
0.67
1
1.5
0.67
1
1.5
Cutting velocity V= (m/min)
Where,
N = Spindle speed (rpm).
D = diameter of work material (mm)
International Journal of Innovations in Engineering and Technology (IJIET)
http://dx.doi.org/10.21172/ijiet.124.04
Volume 12 Issue 4 March 2019 024 ISSN: 2319-1058
Based on the coding and the assigned values as mentioned in table 4, machining of the work material was carried out
for a time period of 30 seconds.
From the experimentation, 27 different types of chip samples were collected. Each chip was takenand its
corresponding weight and length were measuredandfurther the chip thickness was determined.
Figure 1(a). EN36C steel mounted on lathe. Figure 1(b).EN24 steel mounted on lathe.[4]
Figure1(c). Tool insert with holder. Figure 1(d). Carbide tool insert.
After completion of 27 experiments, tensile testing specimen of the work material was prepared according to
ASTM E8 standard and it was subjected to tensile test by INSTRON 1195 UTM machine and the true stress-true
stress curve was obtained from experimental data. From the curve, three points within the yield point and ultimate
stress point were selected and were then plotted on log-log graph paper. The straight line that was obtained on the
log-log graph was extrapolated and the strength coefficient ‘K’ and the strain hardening exponent ‘n’ of the work
material was recorded. In the same context, on getting the value of K and n, power equation (σ = Kɛn) was obtained
as
σEN24 = 1240ɛ0.207
σEN36C = 1495ɛ0.178
Where, σ = true stress (MPa).
ɛ = true strain
Figure 2(a). True stress vs True strain log-log graph for EN 24 steel.[4]
International Journal of Innovations in Engineering and Technology (IJIET)
http://dx.doi.org/10.21172/ijiet.124.04
Volume 12 Issue 4 March 2019 025 ISSN: 2319-1058
Figure 2(b). True stress vs True strain log-log graph for EN36C steel. [2]
Formulations
Uncut chip thickness (t1)= f * sinϕ
Where
ϕ = Principal cutting edge angle (degree).
f = feed (mm/rev)
Formed chip thickness (t2)= W (mm)
Where ρ𝑤𝑙 W = weight of chip (gm).
l = length of chip (mm).
𝑤 = width of chip (mm)
ρ = density of steel (0.008 gm/mm3).
Width of a chip (w) = d (mm)
cos(90 − Ѳ)
Where
d = depth of cut (mm).
Ѳ = Principal approach angle (degree)
Chip reduction coefficient (ξ) = t2 (mm)
t1
Von Mises stress σv = 1.74*K*(lnξ)n (MPa)
Another set of experiments were conducted by face turning on the workpiece at
Cutting speed = 135.72 m/min. Feed = 0.86 mm/rev.
Depth of cut = 1.2 mm.
Machined region from the face surface was sectioned by using hacksaw to prepare sample inorder to identify the
presence of any residual stress through XRD study. Cu target was used for the purpose. Sample from the
unmachined region was also prepared for the same study.
EDX analysis was performed to identify material deposition if any from work material to tool rake face.
III. RESULTS AND DISCUSSIONS
Analysis of variance considering the experimental data for CRC was done. Results of ANOVA are shown in table 5
and table 6.
Table 5. ANOVA analysis for CRC of EN24 machining chip
Result Details
Source SS df MS
Between-treatments 1.5793 2 0.7896 F = 4.72602
Within- treatments 4.0099 24 0.1671
International Journal of Innovations in Engineering and Technology (IJIET)
http://dx.doi.org/10.21172/ijiet.124.04
Volume 12 Issue 4 March 2019 026 ISSN: 2319-1058
Total 5.5892 26
The f-ratio value is 4.72602. The p-value is 0.018598. The result is signification at p < 0.05.
Table 6. ANOVA analysis for CRC of EN36C machining chip
Result Details
Source SS df MS
Between-treatments 0.4969 2 0.2485 F = 5.29175
Within- treatments 1.1268 24 0.047
Total 1.6237 26
The f-ratio value is 5.29175. The p-value is 0.012477. The result is signification at p < 0.05.
It is apparent that the experimental CRC data for both EN24 and EN36C steels are statistically acceptable (p<0.05) and therefore, further study can be explored.
From the input and output data, second order regression equations for CRC and von Mises stress are obtained for
both the steels using MINITAB software which are mentioned below: -
For EN24 Steel
bCRC = 2.3193 + 0.1127x1 - 0.2205x2 + 0.0156x3 - 0.4538x1² + 0.036x2² - 0.35x3² - 0.030x1 x2 - 0.056x1 x3 -
0.161x2x3 (eq.a)[4]
bVMS = 2106.5 + 18 x1 - 87.5 x2 + 14.5 x3 - 234 x1² + 33.7 x2² - 170.9 x3² - 50.2 x1 x2 - 13.9 x1 x3 - 93.6 x2x3
(eq.b)[4]
For EN36C Steel
bCRC = 1.3334 - 0.0561x1 - 0.0322x2 - 0.0163x3 - 0.2708x12 + 0.1474x2
2 + 0.0563x32 + 0.0366x1x2 + 0.0183x1x3 -
0.0093x2x3 (eq. c)[2] bVMS= 1810.7 - 76.2x1 – 25.1x2 - 7x3 - 324x1
2 + 265.7x22 + 157.9x3
2 + 101.5x1x2 + 129.5x1x3 - 374x2x3
(eq. d)[2]
Using above equations, 3D plots were made using MATLAB software considering depth of cut as constant factor
which are mentioned below: -
At lowest depth of cut (-1)
-1
-0.5
0
0.5
1
-1
-0.5
0
0.5
11.6
1.8
2
2.2
2.4
SPEED CODE
CRC FOR DOC -1
FEED CODE
CR
C
-1
-0.5
0
0.5
1
-1
-0.5
0
0.5
11.35
1.4
1.45
1.5
1.55
1.6
SPEED CODE
CRC FOR DOC= -1
FEED CODE
CR
C
Figure 3(a). Variation of CRC w.r.t cutting speed Figure 3(b). Variation of CRC w.r.t cutting speed
and feed code for d.o.c code -1 for EN24 steel. and feed code for d.o.c code -1 for EN36C steel.
From Figure 3(a) at code -1, for EN24 steel, CRC increase with increase of speed was observed. Increased speed
causes temperature rise in primary deformation zone leading to thermal softening. This causes increased CRC at
high speed. Effect of feed on CRC is found to be minimized.
From Figure 3(b) at code -1, for EN36C steel, it was observed that CRC reduced with increase of speed. Strain hardening of the work material occurs at higher speed leading to brittleness transition of the work material. This
causes lower CRC at higher speed. Effect of feed on CRC is found to be minimized.
International Journal of Innovations in Engineering and Technology (IJIET)
http://dx.doi.org/10.21172/ijiet.124.04
Volume 12 Issue 4 March 2019 027 ISSN: 2319-1058
-1
-0.5
0
0.5
1
-1
-0.5
0
0.5
11740
1760
1780
1800
1820
1840
SPEED CODE
VMS FOR DOC -1
FEED CODE
VM
S (
in M
Pa)
-1
-0.5
0
0.5
1
-1
-0.5
0
0.5
11600
1800
2000
2200
2400
2600
2800
SPEED CODE
VMS FOR DOC= -1
FEED CODE
VM
S (
in M
Pa)
Figure 4(a). Variation of VMS w.r.t cutting speed Figure 4(b). Variation of VMS w.r.t cutting speed
and feed code for d.o.c code -1 for EN24 steel. and feed code for d.o.c code -1 for EN36C steel.
From Figure 4(a) at code -1, it is apparent that for EN24 steel, VMS increases with increase of speed. Increase in
CRC at higher speed causes increase of VMS. This is attributed to thermal softening during chip formation. Effect
of feed on VMS is found to be negligible.
From Figure 4(b) at code -1, it is seen that for EN36C steel, VMS reduces with increase in speed. Reduced VMS at
higher speed is owing to brittleness transition of work material. Increased feed causes increase of VMS. Such
increase of VMS is due to thermal softening leading to higher CRC.
At moderate depth of cut (0)
-1
-0.5
0
0.5
1
-1
-0.5
0
0.5
11.8
2
2.2
2.4
2.6
SPEED CODE
CRC FOR DOC 0
FEED
CR
C
-1-0.5
00.5
1
-1
-0.5
0
0.5
11.3
1.35
1.4
1.45
1.5
SPEED CODE
CRC FOR DOC= 0
FEED CODE
CR
C
Figure 5(a). Variation of CRC w.r.t cutting speed Figure 5(b). Variation of CRC w.r.t cutting speed
and feed code for d.o.c code 0 for EN24 steel. and feed code for d.o.c code 0 for EN36C steel.
-1
-0.5
0
0.5
1
-1
-0.5
0
0.5
11850
1900
1950
2000
2050
2100
SPEED CODE
VMS FOR DOC 0
FEED CODE
VM
S
-1
-0.5
0
0.5
1
-1
-0.5
0
0.5
11900
1950
2000
2050
2100
2150
SPEED CODE
VMS FOR DOC= 0
FEED CODE
VM
S (
in M
Pa)
Figure 6(a). Variation of VMS w.r.t cutting speed Figure 6(b). Variation of VMS w.r.t cutting speed
and feed code for d.o.c code 0 for EN24 steel. and feed code for d.o.c code 0 for EN36C steel.
From Figure 5(a) and Figure 5(b), it is observed that at code 0,EN24 and En36C steel follow similar trend as with
Figure 3(a) and Figure 3(b).
International Journal of Innovations in Engineering and Technology (IJIET)
http://dx.doi.org/10.21172/ijiet.124.04
Volume 12 Issue 4 March 2019 028 ISSN: 2319-1058
From Figure 6(a), it is seen that at code 0 for EN24 steel, VMS increases with increase in speed which is attributed
to thermal softening effect at higher cutting speed. VMS reduces with increase of feed because of brittleness
transition of the work material at this cutting condition.
From Figure 6(b), it is observed that at code 0 for EN36C steel, effect of feed on VMS is seemed to be less
significant. Otherwise trend is similar as with Figure 4(b). At highest depth of cut (1)
-1
-0.5
0
0.5
1
-1
-0.5
0
0.5
11.4
1.6
1.8
2
2.2
2.4
2.6
SPEED CODE
CRC FOR DOC 1
FEED CODE
CR
C
-1
-0.5
0
0.5
1
-1
-0.5
0
0.5
11.35
1.4
1.45
1.5
1.55
SPEED CODE
CRC FOR DOC= 1
FEED CODE
CR
C
Figure 7(a). Variation of CRC w.r.t. cutting speed Figure 7(b). Variation of CRC w.r.t. cutting speed
and feed code for d.o.c code 1 for EN24 steel. and feed code for d.o.c code 1 for EN36C steel.
From Figure 7(a) at code 1, for EN24 steel, it is apparent that similar trend is obtained as with Figure 5(a). CRC
increases with increase in speed. CRC reduces with increase in feed, which is attributed to the strain hardening
effect at higher feed. From Figure 7(b) at code 1, for EN36C steel, almost similar trend is observed as with Figure 5(b).
-1
-0.5
0
0.5
1
-1
-0.5
0
0.5
11600
1700
1800
1900
2000
2100
SPEED CODE
VMS FOR DOC 1
FEED CODE
VM
S (
in M
Pa)
-1
-0.5
0
0.5
1
-1
-0.5
0
0.5
11600
1800
2000
2200
2400
2600
2800
SPEED CODE
VMS FOR DOC= 1
FEED CODE
VM
S (
in M
Pa)
Figure 8(a). Variation of VMS w.r.t. cutting speed Figure 8(b). Variation of VMS w.r.t. cutting speed
and feed code for d.o.c code 1 for EN24 steel. and feed code for d.o.c code 1 for EN36C steel.
From figure 8(a) at code 1, for EN24 steel, similar trend as with Figure 6(a) is found. VMS reduces with increase of
feed because of strain hardening of the work material during chip formation. Such phenomenon causes brittleness
transition of work material during chip formation process.SEM examination of under surface of the chip (Figure
9(a)) showed the presence of massive crack indicating brittleness transition of the material during chip formation.
SEM examination of fractured surface of the chip also showed the chip fracture by brittle mode (Figure 9(b)).
Figure 9(a). SEM image of chip under surface Figure 9(b). SEM image of a fractured chip at a cross
at 500X magnification for EN24 steel. [4] section at 2500X magnification for EN24 steel. [4]
International Journal of Innovations in Engineering and Technology (IJIET)
http://dx.doi.org/10.21172/ijiet.124.04
Volume 12 Issue 4 March 2019 029 ISSN: 2319-1058
From Figure 8(b) at code 1, it is seen that for EN36C steel, VMS increases with increase in speed because of thermal
softening. Chip side edge along with top surface was viewed under scanning electron microscope and found that
much deformation had taken place in the chip through ductile mode. (Figure 10(a)) [2]. Moreover, SEM
examination of chip fractured surface indicated ductile separation of chip during fracture. Numerous dimples are
observed in SEM micro-graphof chip fractured surface (Figure 10(b)). This finding illustrates the dominating role of temperature so as to cause ductile transition of the material at primary deformation zone during the process of
chip formation.
VMS reduces with increase in feed. Higher feed causes more strain hardening of the work material leading to
reduced VMS at higher feed.
Figure 10(a). SEM image of the side edge of Figure10(b). SEM image of the fractured surface of
chip at 3000X magnification for EN36C steel. [2] chip at 10000X magnification for EN36C steel. [2]
3.1 Experimental and predicted analysis
Figure 11(a) and Figure 11(b) show the variation between experimental and predicted values for CRC of EN24 chip
and EN36C chip.
Figure 11(a).Comparison chart between experimental CRC and predicted CRC for EN24 chip.
Figure 11(b).Comparison chart between experimental CRC and predicted CRC for EN36C chip.
International Journal of Innovations in Engineering and Technology (IJIET)
http://dx.doi.org/10.21172/ijiet.124.04
Volume 12 Issue 4 March 2019 030 ISSN: 2319-1058
Figure 12(a) and Figure 12(b) show the variation between experimental and predicted values for VMS of EN24 and
EN36C steels respectively.
Figure 12(a).Comparison chart between experimental VMS and predicted VMS for EN24 steel.
Figure 12(b).Comparison chart between experimental VMS and predicted VMS for EN36C steel.
XRD analysis of the work material
For EN24 steel.
20 40 60 80 100 120
5000
10000
15000
INT
EN
SIT
Y
2
INTENSITY
20 40 60 80 100 120
10000
15000
20000
25000
INT
EN
SIT
Y
2
INTENSITY
Figure 13 (a) Phase position for core region Figure 13(b) Phase position for face turningsurface
(un-machined region) obtained from XRD. at V = 135.72 m/min, f = 0.86 mm/rev and d.o.c =
1.2mm obtained from XRD.
International Journal of Innovations in Engineering and Technology (IJIET)
http://dx.doi.org/10.21172/ijiet.124.04
Volume 12 Issue 4 March 2019 031 ISSN: 2319-1058
For EN36C steel.
15 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95
10000
15000
20000
25000
INT
EN
SIT
Y
2
INTENSITY
20 40 60 80 100 120
8000
10000
12000
14000
INT
EN
SIT
Y
2
INTENSITY
Figure 14 (a).Phase position for core region Figure 14 (b) Phase position for face turning
(un-machined region) obtained from XRD. surface at V = 135.72 m/min, f = 0.86 mm/rev
and d.o.c = 1.2mm obtained from XRD.
Figure 13(a) and Figure 13(b) show the peaks (α-Fe) of the un-machined and machined samples for EN24 steel.
From XRD data, it is observed that there is some difference with reference to the peak position considering two conditions. This illustrates the presence of residual stress within the machined sample.
Figure 14(a) and Figure 14(b) show the peaks (α-Fe) of the un-machined and machined samples for EN36C steel.
Using XRD data It is seen that there is also peak shift with the machined sample with respect to the peak position for
the un-machined sample. This finding confirms the presence of residual stress within the machined workpiece for
EN36C steel.
EDX analysis
Considering machining parameters forEN24 steel, V = 125m/min, f = 0.86mm/rev, d.o.c = 1.5mm and time period
(t) = 3min.
Table 7. Chemical composition of diffused and deposited element on tool rake face
Result Type Weight %
Spectrum Label Spectrum 7 C 63.37
O 6.15
Al 0.19
Si 0.76
P 0.00
Ti 15.30
Cr 0.00
Mn 0.01
Fe 11.15
Ni 0.04
Mo 3.03 Total 100.00
International Journal of Innovations in Engineering and Technology (IJIET)
http://dx.doi.org/10.21172/ijiet.124.04
Volume 12 Issue 4 March 2019 032 ISSN: 2319-1058
Figure 15(a) Material deposited at location 1 on tool rake face (EDX)
Figure15(b). Composition of material deposit at location 1 on tool rake face(EDX).
Figure 15(a) &Figure 15(b) showthe material deposited location 1 (EDX) and EDX spectrum respectively for EN24
material deposition on tool rake face. It is seen that work material deposit takes place on the tool rake face in
addition of which some transport from tool occurred to the deposited material through diffusion (Table 7)
Considering machining parameters for EN36C steel at V = 125m/min, f = 0.86mm/rev, doc = 1.5mm and time
period (t) = 3min
Table 8. Chemical composition of diffused and deposited element on tool rake face
Result Type Weight % Spectrum Label Spectrum 3
C 74.60
Al 14.71
Si 5.80
P 0.25
S 0.42
Cr 0.06
Mn 0.05
Fe 2.19
Ni 0.07
Mo 1.87 Total 100.00
Material deposit
location 1.
International Journal of Innovations in Engineering and Technology (IJIET)
http://dx.doi.org/10.21172/ijiet.124.04
Volume 12 Issue 4 March 2019 033 ISSN: 2319-1058
Figure 16. (a) Material deposit at location 2 on tool rake face (EDX)
Figure 16. (b)Composition of material deposit at location 2(EDX).
Figure 16(a) &Figure 16(b) show the material deposited location2 (EDX) and the EDX spectrum for EN36C
material deposition on tool rake face respectively. Material deposition from work material to tool rake face (along with tool elemental diffusion to deposited material) is identified (Table 8)
IV. CONCLUSION
Effect of feed is to lower the VMS at different depth of cut conditions for EN24 steel.
Effect of speed is to raise the VMS at various depth of cut conditions for EN24 steel.
Effect of feed at highest depth of cut condition is to reduce the VMS for EN36C steel. However, at lowest depth of
cut VMS increases with feed.
Effect of speed at highest depth of cut is to raise the VMS for EN36C steel. However, at lowest depth of cut VMS
reduces with speed with EN36C steel.
Residual stress is found to be present in both the steelswhen machined at higher speed, feed and d.o.c condition.
Material transport from work material to tool and tool to work material takes place during machining on EN24 and
EN36C steels through diffusion.
Material deposit
location 2
International Journal of Innovations in Engineering and Technology (IJIET)
http://dx.doi.org/10.21172/ijiet.124.04
Volume 12 Issue 4 March 2019 034 ISSN: 2319-1058
V. ACKNOWLEDGEMENT
The authors sincerely and gratefully acknowledge the assistance provided by IIT Kanpur while using various
laboratories at IIT Kanpur.
VI. REFERENCES [1] Vishal Mishra, Nikhil Bharat & Kalyan Chakraborty, “Comparative assessment on the machinability of EN 24 and EN 36C Steels.”
International Journal of Engineering and Advanced Technology (IJEAT) Volume-8 Issue-3, February 2019) ISSN: 2249 – 8958.
[2] Vishal Mishra & Dr. Kalyan Chakraborty, “Machinability of Nickel Chromium Case Hardened Steel (EN36C).” Global Journal of
Researches in Engineering: A Mechanical and Mechanics Engineering Volume 19 Issue 1 Version 1.0 Year 2019. Online ISSN: 2249-4596
Print ISSN:0975-5861.
[3] Geethanjali KS, Ramesha C.M, Chandan B.R, “Comparative Studies on Machinability of MCLA Steels EN19 and EN24 Using Taguchi
Optimization Techniques.” Materials Today: Proceedings 5 (2018) 25705–25712.
[4] Nikhil Bharat, Dr. KalyanChakraborty, "Machinability of en24 steel (817m40)", International Journal of Latest Trends in Engineering and
Technology Volume 12 Issue 3 January 2019, pp.001-007https://www.ijltet.org/journal_details.php?id=942&j_id=4743