20120140507002

International Journal of Advanced Research in Engineering and Technology (IJARET), ISSN 0976 –
6480(Print), ISSN 0976 – 6499(Online) Volume 5, Issue 7, July (2014), pp. 19-29 © IAEME
19
CONYZA DICORIDES EXTRACT AS EFFICIENT ECO – FRIENDLY
CORROSION INHIBITOR FOR MILD STEEL IN HYDROCHLORIC ACID
SOLUTION
Abd–Alwahab A. Sultan
Chemical Industries Department, Technical Institute, Basrah, Iraq
ABSTRACT
The effect of ethanol extract of leaves of Conyza Dicorides plant on the corrosion inhibition
of mild steel in 1M HCl solution was investigated by weight loss and electrochemical polarization
techniques at temperature range (25–65 ̊C). The Results obtained showed that the percentage
inhibition efficiency increases with the increasing of inhibitor concentration and decreases with the
increasing of temperature. At a concentration of 2 g/L, the percentage inhibition efficiency reached
about (94.87%) at 25 ̊C. The thermodynamic activation functions of dissolution process and
adsorption parameters were calculated and discussed. Adsorption of the additive was found to follow
the Langmuir adsorption isotherm.
Keywords: Adsorption Process, Corrosion Inhibition, Electrochemical Measurement, Mild Steel,
Weight Loss.
1. INTRODUCTION
The corrosion of metallic materials in acidic solution causes considerable costs. In order to
reduce the corrosion of metals, several techniques have been applied. The use of inhibitors during
acid pickling procedure is one of the most practical methods for protection against corrosion in
acidic media. Most of the effective and efficient organic inhibitors are those compounds containing
hetro-atoms such as oxygen, nitrogen, sulphur, and phosphorus which allowed adsorption on the
metal surface [1, 2]. To be effective, an inhibitor must also displace water from the metal surface,
interact with anodic or cathodic reaction sites to retard the oxidation and reduction corrosion
reactions, and prevent transportation of water and corrosion active species on the surface.
Inhibitors, which reduce corrosion on metallic materials, can be divided into three kinds: (i)
inorganic inhibitor, (ii) organic inhibitors, and (iii) mixed material inhibitors [3 – 6]. However, in the
application of these inhibitors for corrosion control, factors such as cost, toxicity, availability and
INTERNATIONAL JOURNAL OF ADVANCED RESEARCH
IN ENGINEERING AND TECHNOLOGY (IJARET)
ISSN 0976 - 6480 (Print)
ISSN 0976 - 6499 (Online)
Volume 5, Issue 7, July (2014), pp. 19-29
© IAEME: http://www.iaeme.com/IJARET.asp
Journal Impact Factor (2014): 7.8273 (Calculated by GISI)
www.jifactor.com
IJARET
© I A E M E

20
environmental friendliness are very important. Thus, recently researchers are focusing on natural
products as corrosion inhibitors.
Naturally occurring substances as inhibitors of acid cleaning process has continued to receive
attention as replacement of synthetic organic inhibitors [7 – 10]. The greatly expanded interest on
naturally occurring substance is attributed to the face that they are cheap, readily available,
ecologically friendly, and poses no threat to the environment.
The objective of the present work was to study the inhibition effect of Conyza Dicorides
leaves extract as cheap, eco-friendly and naturally occurring substances on corrosion behavior of
mild steel in 1M HCl through weight loss and electrochemical polarization measurements. The
adsorption of the inhibitor was investigated and the adsorption parameters in the absence and
presence of the inhibitor were calculated and discussed.
2. EXPERIMENTAL
2.1 MATERIALS AND SOLUTION
The materials used in the present study were mild steel coupons of rectangular shape (53.5 ×
1.8 × 0.3 cm) size having composition of 0.21% C, 0.05% Mn, 0.09% p, 0.05% S, 0.38% Si, 0.01%
Al and the remainder iron containing a hole of about 3 mm diameter near the upper edge. For
electrochemical study, carbon steel circular strips of the same composition with an exposed area of
2.54 cmଶ
were used.
The aggressive solutions of 1M HCl were prepared by dilution of analytical grade 37% HCl
with distilled water.
2.2 INHIBITOR PREPERATION
The leaves of Conyza Dicorides plant which were collected from Abu–AlKhaseeb town
(Basrah, Iraq) washed with distilled water, dried at room temperature and then finely powdered. Two
grams of powder were soaked in 60 ml ethanol at room temperature for 24 hours, and then filtered.
The filtrate was added to an aqueous HCl solution to make 1.0 liter stock solution (1M HCl).
2.3 WEGHT LOSS MEASUREMENTS
The mild steel coupons were polished with emery paper up to 1200 grade, rinsed with
distilled water, dried on a clean tissue, degreased by acetone for 5 sec and dried at room temperature.
After weighing accurately, the coupons were immersed vertically in 100 ml of 1M HCl solution
without and with different concentrations of the inhibitor. After 3 hours immersion time, the coupons
were taken out, rinsed with distilled water, washed with ethanol, dried and weighed according to
ASTM (G1 – 71). Then the tests were repeated at different temperatures by using magnetic stirrer
hot plate. In order to get good repeatability, experiments were carried out twice, and the average
weight loss of two reading was reported.
2.4 ELECTROCHEMICAL MEASUREMENTS
Tafel polarization curves were recorded using computerized electrochemical analyzer model
35415. The electrochemical cell is a conventional three-electrode Pyrex glass cell. The mild steel
specimen was embedded in Teflon holder using epoxy resin with an exposed area of 1cmଶ
. Platinum
was used as an auxiliary electrode. The reference electrode was a Saturated Calomel Electrode (SCE)
coupled to a Luggin capillary whose tip was located between the working electrode and the auxiliary
electrode. The electrolyte (1M HCl solution without and with inhibitor) was added to the test cell.
Ten minutes was given for each experiment to attain the steady state open circuit potential. Then the
carbon steel specimen was polarized to about േ200 mV anodically and cathodically from the open
circuit potential to obtain the corrosion potential, corrosion current and Tafel slopes.

21
3. RESULTS AND DISCUSSION
3.1 EFFECT OF INHIBITOR CONCENTRATION
3.1.1 WEIGHT LOSS TEST
The values of corrosion rate (C.R) (mg. cm-2
. h-1
), inhibition efficiency (I.E%) and the degree
of surface coverage (θ) which obtained from the weight loss test and by using the equations (1) and
(2), at different concentrations of the inhibitor in 1M HCl solution at 25 C for 3 hours immersion
time are listed in Table 1.
θ ൌ
େ.ୖ౥ିେ.ୖ౟
େ.ୖ౥
ሺ1ሻ
I. E% ൌ θ ‫כ‬ 100 ሺ2ሻ
The corrosion rate of mild steel in 1M HCl solution containing inhibitor decreased as the
concentration of the inhibitor increases, as shown in Fig.1. This behavior is the result of the fact that
the adsorption amount and the surface coverage of inhibitor on mild steel increases with increase in
inhibitor concentration [11]. The percentage corrosion inhibition increased as the concentration of
the inhibitor increased from 0.2 to 2.0 g/l. The maximum percentage inhibition efficiency (94.87%)
was obtained at 2 g/l and 25 C, as shown in Fig.2.
Table 1: Corrosion parameters obtained from weight loss of mild steel in 1M HCl containing various
concentrations of the inhibitor at 25 ̊C
Inhibitor (g/l)
C.R
(mg. cm-2
. h-1
)
I.E% θ
0.0 4.0338 - -
0. 2 1.2593 68.78 0.6878
0.5 0.7762 80.75 0.8075
1 0.3288 91.84 0.9184
1.5 0.3067 92.39 0.9239
2 0.2067 94.87 0.9487
Fig 1: Effect of the inhibitor concentration on the corrosion rate of carbon steel in 1M HCl duration
3 hours at 25 ̊C
0
0.2
0.4
0.6
0.8
1
1.2
1.4
0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
C.R(mg/cm2.h)
Inhibitor Concentration (g/L)

22
Fig 2: Variation of inhibition efficiency with concentration of the inhibitor in 1M HCl duration 3
hours at 25 ̊C
3.1.2 POTENTIODYNAMIC POLARIZATION MEASUREMENTS
Electrochemical corrosion kinetic parameters such as corrosion potential (Eୡ୭୰୰ሻ, corrosion
current (iୡ୭୰୰), anodic and cathodic Tafel slopes (βୟ
and βୡ
) and percentage inhibition efficiency
(I.E%) for the corrosion of mild steel in 1M HCl solution at 25Ԩ in the absence and presence of
different concentrations of the extract are given in Table 2 and its corresponding polarization curves
are given in Fig.3. The addition of the extract in 1M HCl solution does not show any significant
change in Eୡ୭୰୰ suggesting that the prepared extract controls the corrosion by controlling both anodic
and cathodic reactions by blocking active anode and cathode sites on the metal surface. This result
reveals that the extract acts as mixed type inhibitor. The corrosion current (iୡ୭୰୰) decreased with
inhibitor concentration. The decrease of corrosion current may be explained by the action of inhibitor
on both cathodic and anodic reactions. The maximum inhibition efficiency obtained was found to be
91.08% in the presence of 2g/l of the extract.
Table 2: Polarization parameters and the corresponding inhibition efficiency for the corrosion of
carbon steel in 1M HCl solution in the absence and presence of different concentrations of the
inhibitor at 25Ԩ
Inhibitor
(g/l) ሺ ሺ
I.E %
0.0 79.4 -123.1 -403.8 231.98 -----
0. 2 69.4 -99.4 -417.4 81.83 64.72
0.5 71.8 -102.5 -424.0 65.24 71.87
1 85.5 -124.7 -418.1 26.84 88.43
1.5 69.7 -140.9 -396.2 25.61 88.96
2 39.7 -101.0 -383.0 20.69 91.08
60
70
80
90
100
0 0.5 1 1.5 2
I.E%
Inhibitor Concentration (g/L)

23
Fig 3: Polarization curves of carbon steel in 1M HCl solution without and with different
concentrations of the inhibitor at 25Ԩ
3.2 EFFECT OF TEMPERATURE ON THE CORROSION INHIBITION Of MILD STEEL
The effect of temperature on the corrosion rate of mild steel in free acid and in presence of the
extract was studied in temperature range of 25-65Ԩ duration 3 hours, using weight loss
measurements and the results are listed in Table 3. It was found that the rate of mild steel corrosion,
in free and inhibited acid solutions, increases with increasing temperature. Consequently, the
inhibition efficiency of the extract decreased with increasing temperature. This result suggests a
physical adsorption of the extract compounds on the mild steel surface. For the optimum
concentration (2 g/L), the corrosion rate of mild steel increased from 0.2067 to 1.5677 mg.cm-2
.h-1
and the inhibition efficiency decreased from 94.87% to 79.54 % with an increase in temperature
from 25 to 65Ԩ, as shown in Fig.4 & Fig.5.
Table 3: Effect of temperature on the corrosion parameters of mild steel in 1M HCl at various
concentrations of the inhibitor duration 3 h
Conc. (g/L) Temp. (o
C) C.R
(mg. cm-2
. h-1
)
I.E% θ
0.0 25 4.0338 - -
35 4.7338 - -
45 5.5694 - -
55 6.7423 - -
65 7.6643 - -
0. 2 25 1.2593 68.78 0.6878
35 1.6474 65.19 0.6519
45 2.5220 54.71 0.5471
55 3.4016 49.54 0.4954
65 4.9033 36.02 0.3602
0.5 25 0.7762 80.75 0.8075
35 0.9847 79.19 0.7919
45 1.4135 74.62 0.7462
55 2.1152 68.62 0.6862
65 3.3915 66.12 0.6612
-600
-500
-400
-300
-200
-2.5 -2 -1.5 -1 -0.5 0 0.5 1
PotentialVsSCE(mV)
Log i (mA/cm^2)
Blank
0.2 g/l
0.5 g/l
1.0 g/l
1.5 g/l
2.0 g/l

24
1 25 0.3288 91.84 0.9184
35 0.6457 86.35 0.8635
45 0.9118 83.62 0.8362
55 1.5101 77.60 0.7760
65 2.5965 66.12 0.6612
1.5 25 0.3067 92.39 0.9239
35 0.5186 89.04 0.8904
45 0.8169 85.33 0.8533
55 1.1508 82.93 0.8293
65 1.7474 77.20 0.7720
2.0 25 0.2067 94.87 0.9487
35 0.4372 90.76 0.9076
45 0.6203 88.86 0.8886
55 0.9559 85.82 0.8582
65 1.5677 79.54 0.7954
Fig 4: Variation of corrosion rate of mild steel in 1M HCl with temperature range (25 – 65Ԩ) for 3 h
immersion time (for optimum concentration)
Fig 5: Variation of inhibition efficiency with the increase in the temperature for mild steel in 1M
HCl at the optimum concentration of inhibitor (2 g/l) for 3 h immersion time
0
0.4
0.8
1.2
1.6
2
20 25 30 35 40 45 50 55 60 65
C.R(mg/cm2.h)
Temperature (˚C)
78
82
86
90
94
20 25 30 35 40 45 50 55 60 65 70
IE%
Temperature (˚C)

25
3.3 ADSORPTION ISOTHERM
The basic information of the interaction between the inhibitor and the mild steel surface can
be provided by the adsorption isotherm. Several attempts were made to fit various isotherms
including Frumkin, Temkin, Frendlich, Bockriss, Flory – Huggins and Langmuir isotherms [12]. In
the present study the results were best fitted by Langmuir adsorption isotherm. According to this
isotherm, the surface coverage (θ) is related to the inhibitor concentration (C) by [13, 14]:
θ
ଵିθ
ൌ Kୟୢୱ. C ሺ3ሻ
Rearranging equation (3) gives:
େ
θ
ൌ
ଵ
୏౗ౚ౩
൅ C ሺ4ሻ
The fitted straight lines were obtained from the plots of C/θ versus C with slopes close to 1,
as seen in Fig.6. The parameters of the adsorption process are listed in Table 4. The strong
correlation (R2
>0.99) suggests that the adsorption of the inhibitor on mild steel surface obeyed the
Langmuir adsorption isotherm. Table.2, also shows that the adsorption equilibrium constant (Kୟୢୱ)
decreases with increasing temperature, which indicates that the extract is easily and strongly
adsorbed on the mild steel surface at relatively lower temperature, but when the temperature
increases, the adsorbed inhibitor tended to desorb from the mild steel surface [15, 16].
Fig 6: Langmuir adsorption isotherm model
Table 4: Adsorption parameters obtained from Langmuir adsorption isotherm at different
temperatures
Temperature
C
Adsorption parameters
R2
Slope Intercept Kୟୢୱ (l/g)
25 0.9996 1.0078 0.0980 10.2040
35 1.0000 1.0532 0.1015 9.8522
45 0.9996 1.0566 0.1491 6.7069
55 0.9998 1.0718 0.1973 5.0684
65 0.9972 1.0771 0.3642 2.7457
0
0.5
1
1.5
2
2.5
3
0 0.5 1 1.5 2
C(g/L)/ſ
C (g/L)
25C
35C
45C
55C
65C

26
3.4 THERMODYNAMIC ACTIVATION FUNCTIONS OF THE CORROSION PROCESS
The apparent activation energy (Eୟሻ, the enthalpy of activation (∆Hୟ) and entropy of activation
(∆Sୟ) for the corrosion of mild steel in 1M HCl in the absence and presence of the extract were
calculated from Arrhenius and Arrhenius transition state equations [17, 18]:
C. R ൌ A exp ൬–
Eୟ
RT
൰ ሺ5ሻ
C. R ൌ ൬
RT
Nh
൰ exp ቆ
∆Sୟ
°
R
ቇ exp ቆ
െ∆Hୟ
°
RT
ቇ ሺ6ሻ
A plot of logarithm corrosion rate of carbon steel obtained from weight loss measurements
versus the reciprocal of absolute temperature ranges (25 – 65Ԩ), gives a straight line as shown in
fig.7 with slope – Eୟ 2.303R⁄ . On the other hand, a plot of log C. R T⁄ versus 1 T⁄ gives a straight line
(fig.8) with a slope equal to െ ∆Hୟ 2.303R⁄ and an intercept of log R Nh⁄ ൅ ∆Sୟ 2.303R⁄ , from
which the values of ∆Hୟ and ∆Sୟwere calculated. The values of Eୟ, ∆Hୟ and ∆Sୟ are listed in
Table 5.
The apparent activation energy (Eୟሻ values ranged from 28.5710 to 40.2563 KJ mol-1
and are
lower than the value of 80 KJ mol-1
required for chemical adsorption, indicating that the adsorption
of ethanol extract of leaves of Conyza Dicorides on mild steel surface conforms with the mechanism
of physical adsorption [19]. The positive signs of enthalpies reflect the endothermic nature of
dissolution process. Entropy of activation (∆Sୟ) values are negative both in the absence and presence
of the plant extract, and the values in the presence of the extract are less negative than those in the
absence of the extract. This also indicates inhibition of the corrosion process [20].
Table 5: Activation parameters for the dissolution of mild steel in1M HCl with different
concentrations of inhibitor
Conc. (g/L) Ea (KJ mol-1
) ∆Hୟ
°
(KJ mol-1
) ∆Sୟ
°
(KJmol-1
K-1
)
0.0 13.6075 10.9919 -195.5521
0. 2 28.5710 25.9546 -156.3979
0.5 30.7135 28.1013 -153.6751
1 41.4128 38.7989 -123.9043
1.5 35.5864 32.9724 -143.9943
2 40.2563 37.6416 -131.2032
Fig 7: Arrhenius plots of lnC.R versus 1/T for mild steel in 1M HCl solution in the presence of
different concentrations of the extract
-2
-1
0
1
2
3
0.0029 0.003 0.0031 0.0032 0.0033 0.0034
Ln(C.R)(mg/cm2.h)
1/T (K -1)
Blank
0.2g/L
0.5g/L
1g/L
1.5g/L
2g/L

27
Fig 8: Arrhenius plots of ln (C.R/T) versus 1/T for mild steel in 1M HCl solution in the presence of
different concentrations of the extract
4. CONCLUSIONS
The following results can be drawn from this study:
1) The ethanol extract of Conyza Dicorides leaves acts as efficient inhibitor for mild steel in 1M
HCl solution.
2) The use of Conyza Dicorides leaves extract, as corrosion inhibitor is environmentally safe, eco-
friendly, cost effective and easily available.
3) The maximum inhibition efficiency was found to be 94.87% at an optimum concentration of 2g/l
of the extract.
3) Results obtained in weight loss test have good agreement with potentiodynamic polarization
measurements.
4) The inhibition efficiency of Conyza Dicorides leaves extract decreases with the rise of
temperature.
5) The extract acts on mild steel surface as mixed type inhibitor with a physisorption mechanism.
6) The adsorption of the different concentrations of the Conyza Dicorides leaves extract on the
surface of mild steel in 1M HCl solution follows Langmuir adsorption isotherm.
SYMBOLS
A: Constant
βୟ
, βୡ
: Anodic and cathodic Tafel slopes (mV Decሻ⁄
C: Concentration of the extract (g/l)
C. R: Corrosion rate of mild steel (mg. cm-2
. h-1
)
-8
-6
-4
-2
0
0.0029 0.003 0.0031 0.0032 0.0033 0.0034
Ln(C.R/T)(mg/cm2.h.K)
1/T (K -1)
Blank
0.2g/L
0.5g/L
1g/L
1.5g/L
2g/L

28
C. R୭: Corrosion rate of mild steel in the absence of the extract (mg. cm-2
. h-1
)
C. R୧: Corrosion rate of mild steel in the presence of the extract (mg. cm-2
. h-1
)
Eୡ୭୰୰: Corrosion potential (mV)
Eୟ: Activation energy (KJ mol-1
)
Hୟ: Enthalpy of activation (KJ mol-1
)
h: Planks constant (6.626*10ିଷସ
ሻ (J.s)
IE%: Percentage inhibition efficiency
iୡ୭୰୰: Corrosion current density (µA/cmଶ
)
Kୟୢୱ: Adsorption equilibrium constant (l/g)
N: Avogadro’s number (6.022*10ଶଷ
ሻ (molିଵ
)
R: Gas constant (8.314) (J. molିଵ
. Kିଵ
)
Sୟ: Entropy of activation (KJ. molିଵ
. Kିଵ
)
T: Temperature (Ԩ)
Θ : Surface coverage
REFERENCES
[1] M. Dahmani, A. Et – Touhami, S. S. Al – Deyab, B. Hammouti and A. Bouyanzer (2010),
“Corrosion inhibition of C38 steel in 1M HCl: a comparative study of black pepper extract
and its isolated piperine”, Int. J. Electrochem. Sci, Vol.5, Issue 8, pp. 1060–1069.
[2] M. A. Amin, S. S. Abd El – Rehim, E. E. El – Sherbini and R. S. Bayoumi (2007), “The
inhibition of low carbon steel corrosion in hydrochloric acid solutions by succinic acid part I.
weight loss, polarization, EIS, PZC, EDX and ESM studies”, Electrochim. Acta, Vol.52,
pp. 3588–3599.
[3] J. Cruz, R. Martinez, J. Genesca and E. Garcia – Ochoa (2004), “Experimental and
theoretical study of 1 – (2 – ethylamino) – methylimidazoline as an inhibitor of carbon steel
corrosion in acid media”, J. Electroanalytical Chemistry, Vol.566, Issue 1, pp. 111–121.
[4] H. Ashassi – Sorkhabi and E. Asghari (2008), “Effect of hydrodynamic conditions on the
inhibition performance of L – methionine as "green" inhibitor”, Electrochim. Acta, Vol.54,
pp. 162–167.
[5] A. S. Fouda and H. El – Dafrawy (2007), “Inhibitive effect of some pyrimidine derivatives on
the cycle stressed specimens of stainless steel type 304 in acidic media”, Int. J. Electrochem.
Sci, Vol.2, pp. 721–733.
[6] N. O. Eddy, S. A. Odemelam and A. O. Odiongenyi (2008), “Ethanol extract of musa
acuminate peel as an eco – friendly inhibitor for the corrosion of mild steel in H2SO4,
Advanced in Natural and Applied Sciences, Vol.2, pp. 35–42.
[7] J. Morris Princy, J. Christyezhilarasi, D. Kavitha and N. Sulochana (2009), Natural product
extract as eco – friendly corrosion inhibitor for commercial mild steel in 1M HCl – part II,
J. Ind. Council Chem, Vol.26, Issue 2, pp.153–157.
[8] U. Garg and R. K. Tak (2010), “Inhibition of the corrosion of mild steel in acid media by
naturally occurring acacia Senegal”, E – Journal of Chemistry, Vol.7, Issue 4, pp. 1220–1229.

29
[9] M. Lebrini, F. Robert and C. Roos (2011), “Alkaloids extract from palicourea guianensis
plants as corrosion inhibitor for C38 steel in 1M hydrochloric acid medium”, Int. J.
Electrochem. Sci., Vol.6, pp. 847–859.
[10] P. Bothi and M. Gopolakrishnan, Solanum tuberosum as an inhibitor of mild steel corrosion
in acid media (2009), Iran. J. Chem. Eng., Vol.28, pp. 77–84.
[11] M. Abdallah, M. Al – Ages and S. A. Fouda (2009), “Phenyl hydrazone derivatives as
corrosion inhibitors for α – brass in hydrochloric acid solutions”, Int. J. Electrochem. Sci.,
Vol.14, pp. 336–352.
[12] A. O. James and O. Akaranta (2009), Corrosion inhibition of aluminum in 2 M hydrochloric
acid solution by the acetone extract of red onion skin, African J. Pure and Applied Chemistry,
Vol.3, pp. 262–268.
[13] N. O. Eddy, S. A. Odoemelam and A. J. Mbaba (2008), “Inhibition of the corrosion of mild
steel in HCl by sparfloxacin”, African J. Pure and Applied Chemistry, Vol.2, Issue 12,
pp. 132–138.
[14] S. M. Milic and M. M. Antonijevic (2009), Some aspect of copper corrosion in presence of
benzotriazole and chloride ions, Corrosion Science, Vol.51, Issue 1, pp. 28–34.
[15] D. Zhang, Q. Cai, X. He, L. Gao and G. Kim (2009), “The corrosion inhibition of copper in
hydrochloric acid solutions by a tripeptide compound”, Corrosion Science, Vol.51, Issue 10,
pp. 2349–2354.
[16] Q. Qu, Z. Hao, L. Li, W. Bai, Y. Liu and Z. Ding (2009), “Synthethesis and evaluation of
trishydroxymethyl – (2 – hydroxybenzylidenamino) – (methan as a corrosion inhibitor for
colled rolled steel in hydrochloric acid”, Corrosion Science, Vol.51, pp. 569–574.
[17] K. M. Mohana and A. M. Badiea (2008), “Effect of sodium nitrite – borax blend on the
corrosion rate of low carbon steel in industrial water medium”, Corrosion Science, Vol.50,
Issue 12, pp. 2939–2947.
[18] L. Larabi, O. Benali and Y. Harek (2006), “Corrosion inhibition of copper in 1 M HNO3
solution by n – phenyl oxalic dihydrazide and oxalic n- phenylhydrazide n̕ -
phenylthiosemicarbazide”, Portugaliae Electrochimica Acta, Vol.24, pp. 337–346.
[19] J. T. Nwabanne and V. N. Okafor (2011), “Inhibition of Corrosion of Mild Steel in Acidic
Medium by Vernonia Amygdaline: Adsorption and Thermodynamics Study”, Journal of
Emerging Trends in Engineering and Applied Sciences, Vol.2, Issue 4, pp. 619-625.
[20] P. C. Okafor, I. E. Uwah, O. O. Ekerenam and U. F. Ekpe (2009), “Combretum bracteosum
extracts as eco-friendly corrosion inhibitor for mild steel in acidic medium”, Pigment &
Resin Technology, Vol.38, No.4, pp. 236-241.
[21] Abdulrasoul Salih Mahdi, “Urea Fertilizer as Corrosion Inhibitor for Reinforced Steel in
Simulated Chloride Contaminated Concrete Pore Solution”, International Journal of
Advanced Research in Engineering & Technology (IJARET), Volume 5, Issue 5, 2014,
pp. 30 - 39, ISSN Print: 0976-6480, ISSN Online: 0976-6499.
[22] Hameed Hussein Alwan, “Adsorption Mechanism for Corrosion Inhibition of Carbon Steel
on HCL Solution by Ampicillin Sodium Salt”, International Journal of Advanced Research in
Engineering & Technology (IJARET), Volume 4, Issue 7, 2014, pp. 236 - 246, ISSN Print:
0976-6480, ISSN Online: 0976-6499.

20120140507002

Recommended

Recommended

More Related Content

What's hot

What's hot (19)

Viewers also liked

Viewers also liked (9)

Similar to 20120140507002

Similar to 20120140507002 (20)

More from IAEME Publication

More from IAEME Publication (20)

Recently uploaded

Recently uploaded (20)

20120140507002