scholarly journals Potensi Ekstrak Daun Pepaya sebagai Inhibitor Korosi dalam Media Asam Klorida pada Baja ST37

Author(s):  
Dwi Kemala Putri ◽  
Addin Akbar

Corrosion is a decrease in the quality of a metal material caused by a reaction with the environment. Reducing the corrosion rate on steel can be done by adding an inhibitor. Papaya leaf extract (Carica papaya.L) can be used as a corrosion inhibitor by immersion method. The effect of inhibitor on corrosion rate had been studied using weight loss method, potentiodynamic polarization method, and observation of steel surface using photooptic. It was found that corrosion rate decrease with increase concentration of papaya leaves extract. The highest inhibiton efficiency is 87.8% in 0.2 M hydrochloric acid with 2% concentration of papaya leaves extract. Potentiodynamic polarization method showed that papaya leaves extract decrease corrotion current. Inhibiton efficiency reached 81.58% in 2% extract concentration in which corrosion current decrease from 0.0266 mA/cm2 to 0.0049 mA/cm2. Analysis of photooptic showed that there is difference on steel surface corroded in hydrochloric acid with inhibitor and without it.

2012 ◽  
Vol 58 (2) ◽  
Author(s):  
W. B. Wan Nik ◽  
S. Syahrullail ◽  
R. Rosliza ◽  
M. M. Rahman ◽  
M. F. R. Zulkifli

The aim of this study is to determine the corrosion effect of palm oil methyl ester (POME) on aluminium alloy 5083 (AA5083). The static immersion test was carried out at 60°C for 68 days according to ASTM G–31–72. The corrosion analysis was done by using weight loss method and electrochemical test. The result from weight loss method shows the decreasing in weight loss of AA5083 which signifies the ability of POME to reduce corrosion rate. The electrochemical test shows the decreasing in polarization resistance,Rp, while the corrosion current densities, Icorr, increase. The corrosion rate reduces from 2.250mpy to 0.1946mpy. The low concentration of fatty acid C18:2 and high anti oxidant element contributes to the reduction of corrosion rate of AA5083 in POME.


2012 ◽  
Vol 12 (1) ◽  
pp. 87
Author(s):  
Maria Erna ◽  
Emriadi Emriadi ◽  
Admin Alif ◽  
Syukri Arief ◽  
Mohd Jain Noordin

Carboxymethyl chitosan (CMC) was synthesized with different methods by reacting chitosan with monochloroaceticacid in the presence of sodium hydroxide under variation conditions. The above samples were characterized byFourier transform infrared spectroscopy (FTIR) and soluble in water in range of pH. The CMc were soluble in watera wide range of pH and applied as corrosion inhibitor for steel in water. The inhibiting influence of CMC was studiedby potentiodynamic polarization method. It was found thad corrosion rate was dependent on water pH and CMCconcentration. The results show that optimum the inhibition efficiency at pH 5 and 1 ppm concentration CMC, i.e.,77%. The adsorption of used compound on the steel surface obeys modified Langmuir isotherm. Polarizationmeasurement show that the CMC acts essentially as a anodic-type inhibitor.


2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Yuli Yetri ◽  
Desi Mita Sari ◽  
Sri Handani

<p class="51JUDULABSTRAK">Telah dilakukan penelitian untuk mengendalikan laju korosi baja St-37 dalam medium asam klorida dan natrium klorida menggunakan inhibitor ekstrak daun teh <em>(Camelia sinensis)</em>. Metode weight loss dan metode potensiodinamik untuk menentukan laju korosi, dalam medium HCl 3 % dan NaCl 3 %, dengan konsentrasi inhibitor yang ditambahkan bervariasi mulai dari 1 % hingga 10 % dengan perendaman selama empat hari. Hasil penelitian menunjukan bahwa laju korosi berkurang dengan meningkatnya konsentrasi inhibitor yang ditambahkan, Peningkatan konsentrasi inhibitor diikuti juga dengan meningkatnya nilai effisiensin inhibisinya. Nilai efisiensi terbesar 86,3 % dengan penambahan konsentrasi inhibitor 10 % untuk medium korosif HCl dan dengan konsentrasi yang sama untuk NaCl mencapai 92,0%.  Analisis morfologi permukaan dengan foto optik memperlihatkan permukaan baja dengan penambahan ekstrak daun teh mengalami korosi  lebih sedikit dibandingkan dengan tanpa inibitor. Hal ini menunjukan bahwa inhibitor ekstrak daun teh sangat efisien untuk mengendalikan laju korosi dalam medium korosif HCl dan NaCl.</p><p class="52ISIABSTRAKCxSpMiddle"> </p><p class="52ISIABSTRAKCxSpMiddle">A research  to control corrosion rate of St-37 steel in acid chloride and sodium chloride medium using tea leaf (Camellia sinensis) extract inhibitor has been done. The method used is potentiodynamic to see the value of the corrosion current and weight loss method for corrosion rate.. Corrosive medium used were HCl 3% and NaCl 3%. The concentration of the extract used range from 1%-10% and the immersion time is four days. The results showed that the corrosion rate was greatest in the corrosive medium without addition of inhibitors, whereas the corrosion rate decreases with the addition of inhibitors, it is also evident from the results of the Tafel plot shows I<sub>cor </sub>impairment. The greater the concentration of inhibitor that is used the lower the corrosion rate. Greatest efficiency values both for medium corrosive obtained at inhibitor concentrations of 10%, 86,3% in HCl and 92% in NaCl. This shows that tea leaves extract inhibitor is very efficient in controlling the rate of corrosion in HCl and NaCl medium. From the optical photograph  analysed on the surface morphology of St-37 steel showed that the addition of tea leaf extract suffered less corrosion.</p>


2019 ◽  
Vol 9 (21) ◽  
pp. 4684 ◽  
Author(s):  
Sihem Lahrour ◽  
Abderrahim Benmoussat ◽  
Brahim Bouras ◽  
Asma Mansri ◽  
Lahcene Tannouga ◽  
...  

C-Mn steels, commonly employed in structural applications, are often exposed to near-neutral aerated environments and hence subjected to general corrosion. In broader contexts, for example during pickling, acidizing treatments, or acid-releasing processes, where steel comes in contact with more aggressive solutions, the use of corrosion inhibitors is a supplementary strategy to cathodic protection and/or coating. This work focuses on the C-Mn steel corrosion protection in the presence of HCl, either as process fluid or by product. In order to avoid the toxicological issues related to conventional synthetic products, a bio-copolymer containing glycerin-grafted starch, synthesized by modification of maize starch, was studied as a “green” corrosion inhibitor by the weight loss method and electrochemical techniques (open circuit potential, potentiodynamic polarization and electrochemical impedance spectroscopy). Corrosion-related parameters, such as inhibitor concentration and temperature, were varied and optimized to characterize the corrosion process. Results showed that inhibition efficiency increases with increasing bio-copolymer concentration, reaching a maximum of 94%at the concentration of 300 mg L−1. The kinetic and thermodynamic parameters were determined and discussed. The obtained values of corrosion potential and corrosion current density, Ecorr and icorr, obtained by potentiodynamic polarization, are in agreement with the weight loss method. The corrosion current densities decrease when the concentration of the inhibitor increases.


2013 ◽  
Vol 318 ◽  
pp. 312-315
Author(s):  
Xiong Yang ◽  
Jian Tong ◽  
Xiao Ming Li

The effects of concentration and temperature of hydrochloric acid and etching time on the corrosion rates of 434 stainless steel fibres are investigated by using weight loss method,The results show that with the concentration of hydrochloric acid increase,the temperature of hydrochloric acid rise, etching time prolonging, the corrosion rate of 434 stainless steel fibres is increased, and the corrosion rate of smalldimension of 434 stainless steel fibres faster.Though Cl- of hydrochloric acid doesn’t take direct part in the reaction,the corrosion rate is significantly accelerated.


2015 ◽  
Vol 1120-1121 ◽  
pp. 1059-1063
Author(s):  
Cai Xiang Gu ◽  
Guang Wei Liu ◽  
Yu Dong Xu

The influence of different flame of gas welding on corrosion behavior of the carbon steel’s heat affected zone in seawater were studied by the weight-loss method, electroanalytical chemistry method and surface and microstructure observation. The result indicate that when gas welding the carbon steel, the corrosion rate of the heat affected zone under the influence of mild carbonizing flame is 0.1252[g/(m2•h)], in contrast, the corrosion rate of that under the influence of neutral flame is 0.1025[g/(m2•h)]; the order of corrosion current shows as follows: Imild carbonizing flame>Ineutral flame>Ibase metal; the order of measured corrosion potential as follows: Ebase metal>Eneutral flame>Emild carbonizing flame. Compared with the base metal, the heat effected zone are more likely to corrosion, corrosion resistance of the sample under mild carbon flame are the worse.


Author(s):  
Meryanalinda Meryanalinda ◽  
Dedy Rachman Ardian ◽  
Mochammad Shocib ◽  
Ahmad Yasin

Corrosion is a process of degradation metal quality which is very detrimental in the industry. Especially in an industries related to utilization of acidic liquids such assulfuric acid, hydrochloric acid, etc. If corrosion rate of carbon steel can be estimated, the prediction of remaining life of carbon steel, and the preventive methods of corrosionwould be more appropriate. This will reduce technical, economic and aesthetic losses. The aims of this study was to determine corrosion rate of carbon steel in sulfuric acid. This study used ASTM A 387 Grade 12 and ASTM A 283 Grade A carbon steel type fortank material, where one material is represented by 5 specimen. The corrosion rate of Specimens were measured by the weight loss method for 31 days. The 5 specimens were divided into 3 regions where specimens no.1 and 2 were immersed in  sulfuric acid , specimens no.3 were in the middle area or zone level (partially immersed), and specimens no.4 and 5 were not immersed in sulfuric acid. The highst corrosion rate occured on specimen No.3 with maximum corrosion rate was 0,097 mm/y for ASTM A 387 Gr 12 and 0,096 mm/y untuk material ASTM A 283 Gr A. The results of corrosion rate on ASTM A 387 Grade 12 material are lower than corrosion rate of ASTM A 283 Grade A material. This is caused by presence of Mo and Cr alloy elements in ASTM A 387 Grade 12.


2009 ◽  
Vol 16 (06) ◽  
pp. 845-853 ◽  
Author(s):  
MUTHU NADAR LAVANYA ◽  
DEVARAYAN KESAVAN ◽  
NAGARAJAN PRABHAVATHI ◽  
NAGARAJAN SULOCHANA

The corrosion inhibition effect of 3-hydroxyflavone was studied on mild steel in 1 M hydrochloric acid ( HCl ). The anticorrosive effect was evaluated by weight loss and electrochemical methods which include Tafel polarization and AC impedance studies at 300 K. In weight loss method, the inhibition efficiency increased with increase in inhibitor concentration, and decreased with increase in temperature and immersion time, and acid concentration. The inhibitor showed maximum efficiency of 91% at 4 × 10-4 M concentration in 1 M hydrochloric acid. The Tafel polarization study showed that the inhibitor behaves likely as cathodic type. The corrosion inhibition effect measured by weight loss method and electrochemical studies was in good agreement with each other. The surface analysis was done by using scanning electron microscope (SEM). Several adsorption isotherms are assessed to study the adsorption behavior of the inhibitor on the mild steel surface. The negative value of ΔG ads indicates the spontaneous adsorption of the inhibitor on mild steel surface.


2002 ◽  
Vol 67 (11) ◽  
pp. 777-782 ◽  
Author(s):  
Dragutin Drazic ◽  
Jovan Popic

By combining electrochemical corrosion rate measurements and spectrophotometric analysis of the electrolyte it was shown that at room temperature chromium dissolves in deaerated 0.1M Na2SO4 + H2SO4 (pH1) solution as Cr(II) and Cr(III) ions in he ratio Cr(II):Cr(III)?7:1. This process was stable over 4h without any detectable change. The total corrosion rate of chromium calculated from the analytical data is about 12 times higher, than that determined electrochemically by cathodic Tafel line extrapolation to the corrosion potential. This finding was confirmed by applying the weight-loss method for the determination of the corrosion rate. This enormous difference between these experimentally determined corrosion rates can be explained by the rather fast, "anomalous" dissolution process proposed by Kolotyrkin and coworkers (chemical reaction of Cr with H2O molecules) occurring simultaneously with the electrochemical corrosion process.


2016 ◽  
Vol 12 (1) ◽  
pp. 27
Author(s):  
Maria Erna ◽  
Emriadi Emriadi ◽  
Admin Alif ◽  
Syukri Arief

The thermodynamic properties and characterizations of corrosion inhibition of chitosan nano-particles on the surface of mild steel in peat water media had been studied using weight loss method at temperatures of 30 - 50 <sup>o</sup>C. Steel surfaces were characterized by FT-IR spectra and SEM-EDS morphology photos. The research found that the value of DG<sup>o </sup>approaching -40 kJmol<sup>-</sup><sup>1</sup>. The negative value of Gibbs free energy shows that the adsorption of inhibitor molecules on the surface of mild steel was achemisorption and it occurred spontaneously. Meanwhile, the values of DH<sup>o </sup>is also negative confirming that the adsoprtion of inhibitor molecules is an exothermic process. The value of DS<sup>o </sup>obtained is positive, it indicates hat the inhibitor molecules were adsorbed spontaneously on the mild steel surface. The analysis on mild steel surfaces hows that the nano-particle chitosan was adsorbed on the steel surface to form the complex compounds.


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