Experimental Investigation on Characteristic Study of the Carbon Steel C45 in Different Working Conditions Using Toughness Test

International
OPEN ACCESS Journal
Of Modern Engineering Research (IJMER)
| IJMER | ISSN: 2249–6645 | www.ijmer.com | Vol. 5 | Iss.4| Apr. 2015 | 1|
Experimental Investigation on Characteristic Study of the
Carbon Steel C45 in Different Working Conditions Using
Toughness Test
R.Raj Mohan1
, P.Arul Solomon2
, A.S.Bhuvanesh Kanna3
, C.Giridhar Chellappa4
,
J.Jaganraj5
1,2,3,4,5
(Department of Mechanical Engineering, TRP Engineering College, India
I. INTRODUCTION
The mechanical characteristics of medium carbon steel C45 under various notch configurations
(without notch, V-Notch, Drilled hole notch with different heat treated conditions (Unhardened, hardening,
tempering) are studied. Here we are using Palm oil [1] as the quenching medium and its reaction over the
specimens are also been studied. The toughness test of the specimen is carried under Charpy Impact testing
equipment. The experimental results are compared with the analysis, results where the analysis is made in
ANSYS WORKBENCH.
Medium carbon steel has carbon content of 0.45%. Medium carbon steel is the most common form of
steel as it provides material properties that are acceptable for many applications. It is neither externally brittle
nor ductile due to its amount of carbon content. It has minimum tensile strength and malleable. Steel with
normal carbon content has properties similar to iron. As the carbon content increases, the metal becomes
harder and stronger but less ductile and more difficult to weld. The process heat treatment is carried out first
by heating the metal and then cooling it in specific medium. The purpose of heat treatment is to soften the
metal and relive the stress set up in the material. Mechanical properties depend largely upon the various form
of heat treatment operations and cooling rate. Hence depending upon the properties and the applications that
may be required for any design purpose, a suitable form of heat treatment should be adopted [2].
Reason behind using palm oil as a quenching medium instead of other common medium like water
and brine solution is because it has been established that palm oil can also be used as a quenching medium for
medium carbon steel since the mechanical strength of some of the samples quenched with palm oil improved
when compared with those of the as-received sample. Palm oil cooling improves the ductility of the steel
because of its lower cooling rate compared with water. Therefore, palm oil will be a viable quenching medium
in such cases for which the improved elongation of the samples is critical [3].
The purpose of impact testing is to measure an object's ability to resist high-rate loading. It is usually
thought of in terms of two objects striking each other at high relative speeds. A part or material's ability to
resist impact often is one of the determining factors in the service life of a part, or in the suitability of a
designated material for a particular application. Impact resistance can be one of the most difficult properties to
determine. The ability to determine this property is a great advantage in product liability and safety.
Specimen types include notch configurations such as V-Notch, Drilled-Hole Notch, as well as Un-
notched specimens. Then the impact test is to be carried on Charpy impact testing equipment has the reading
upto 300 joules.
The main objective of this study is to investigate the effect of notch configurations of the specimen
treated under different working conditions.
ABSTRACT: In this paper, the mechanical characteristics of C45 medium carbon steel are investigated
under various working conditions. The main characteristic to be studied on this paper is impact toughness
of the material with different configurations and the experiment were carried out on charpy impact testing
equipment. This study reveals the ability of the material to absorb energy up to failure for various
specimen configurations under different heat treated conditions and the corresponding results were
compared with the analysis outcome.
Keywords: C45 medium carbon steel, failure, heat treated conditions, impact toughness, specimen
configuration.

Experimental Investigation on Characteristic Study of the Carbon Steel C45 in Different……
II. Material Selection And Experimentation
2.1 Material
In this study a set of medium carbon steel C45 specimens have been used, the density is 7.85 gm/cm3,
where the chemical composition is (0.42 C, 0.24Si, 0.69 Mn, 0.019P, 0.016Cr, 0.12Ni, 0.16Cu, 0.12Mo,
0.02Ti, 0.002V, 0.004W) .
2.2 Notch Configurations
Three different notches are made in the C45 specimen namely, V-Notch, Drilled-Hole notch and Un-
Notched specimens. The notch configurations are taken from ASTM.
2.3 Specimen Dimensions
The dimensions of the specimen used in this project is the standard one which is also taken from
ASTM (W= 2B, S = 4W& a/W ≈ 0.5) [4]
.
Fig.1. Specimen configuration
2.4 Hardening
The main purpose of hardening is to develop a high hardness level in components for heavy duty
service. This treatment consists of heating, soaking and cooling.
 Heating: Specimen is heated slowly in furnace to a temperature up to 850⁰ which is above the upper
critical temperature [5].
 Soaking: Steel is held at this temperature for 1 hour.
 Cooling: Steel is quenched in oil to attain room temperature.
2.5 Tempering
Hardening treatment develops maximum hardness, excellent wear resistance and high strength in
steel. At the same time, it adversely affects properties such as ductility and toughness. Hence in hardened
condition, steels are generally brittle. The ductility and toughness of steel can be enhanced and these internal
stresses are relieved by another heat treatment process called tempering.
Tempering was performed at 600°C for one hour then the specimen is brought to the room
temperature by means of air cooling [5].
Fig.2. Time temperature Diagram for heat treatment of C45
2.6 Charpy impact test
Impact tests are designed to measure the resistance to failure of a material to a suddenly applied force.
The test measures the impact energy, or the energy absorbed prior to fracture. Charpy bar test pieces (12x6x50
mm3
) were machined. Three specimens of each set were tested to ensure the repeatability from which the
average is calculated.

III. Results And Discussions
3.1 Experiment
The following table shows the impact energy values and corresponding impact strength for each type
of specimen
Table.1. 1 Experimental Data
S.No Heat treatment Specimen Configuration Energy absorbed
(J)
C/S Area
(mm2
)
Impact strength
(J/mm2
)
1
Unhardened
V-Notch 29 60 0.483
2 Drilled Hole Notch 26 42 0.619
3 Hardened V-Notch 38 60 0.633
5 Tempered V-Notch 42 60 0.700
Impact Strength (J/mm2
) = (energy absorbed) / (specimen cross sectional area)
3.2 Variation of impact strengths
The following graphs shows the impact strength variation of impact strengths
Fig 3. Impact Strength for V-notch
Fig 4. Impact Strength for Drilled hole notch

From the experimental results, it is clearly explained that the hardened specimen too achieve good
toughness characteristics by quenching it in palm oil. Generally hardened specimens are lack in toughness but
here it compensates its character nearer to the tempered one.
3.3 Analysis Results
Analysis was done for the C45 designing the notch in ANSYS WORKBENCH. As the mechanical
properties like yield strength and ultimate strength are mostly the same for hardened and tempered specimen
So, the two different conditions are considered as one and the results were taken.
Fig 5. Energy stored for v notch specimen without heat treatment
Fig 6. Energy stored for drilled hole notch specimen without heat treatment
Fig 7. Energy stored for v-notch specimen with heat treatment

Fig 8. Energy stored for Drilled hole notch specimen without heat treatment
3.4 Result and Comparison
The impact strength / Energy absorbed by the specimen was obtained through experimentation and
analysis, values obtained from the both cases are compared and shown in below figure 9 and figure 10.
Fig 9. Analysis and experiment comparison for v-notch specimen
Fig 10. Analysis and experiment comparison for drilled hole notch specimen

The above analysis results show the variations between the unhardened and heat treated specimen in
energy absorption. The internal energy absorbed by the heat treated specimen is higher than the un-hardened
one which describes that the heat treated specimens are good in toughness characteristics.
IV. Conclusion
 From the experimental values the impact strength was found to be in the order, Tempered > hardened >
unhardened.
 From Analysis results also shows that the heat treated specimens achieves greater energy absorbed than
unhardened specimens.
 The same result is experienced for both notched (V- notch & drilled hole) and un-notched specimens.
 By varying the notch configuration it is found that drilled hole notch had more impact strength than v -
notch specimen.
REFERENCES
[1] M. B. Ndaliman , An Assessment of Mechanical Properties of Medium Carbon Steel under Different Quenching
Media, A.U J.T., 10(2) , 2006 ,100-104.
[2] Senthilkumar and T. K. Ajiboye , Effect of Heat Treatment Processes on the Mechanical Properties of Medium
Carbon Steel , Journal of Minerals & Materials Characterization & Engineering,11(2), 2012, 143-152.
[3] Jamiu Kolawole Odusote1, Tajudeen Kolawole Ajiboye and Abdulkarim Baba Rabiu , Evaluation of Mechanical
Properties of medium Carbon Steel Quenched in Water and Oil, AU J.T., 15(4) , 2012 , 218-224.
[4] Zhu, Xian-Kui and Joyce, James A., Review of fracture toughness (G, K, J, CTOD, CTOA) testing and
standardization Xian-Kui Zhu , U.S. Navy Research ,49 , 2012 , 1-47.
[5] Jiri MALINA, Hana STANKOVA , Jaroslav DRNEK , Zbysek NOVY and Bohuslav MASEK , Influence Of
Thermomechanical Treatment On The Steel C45 Fatigue Properties, Trnava, Slovak Republic , 2005 ,784-788.

Experimental Investigation on Characteristic Study of the Carbon Steel C45 in Different Working Conditions Using Toughness Test

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