Hasil Pencarian  ::  Simpan CSV :: Kembali

"Laju korosi material baja API 5L X52 di dalam larutan 3,5 % NaCl teraerasi pada kondisi aliran turbulen berlangsung relatif tinggi yang dapat mencapai lebih dari 80 mpy (2 mm/tahun). Upaya menurunkan laju korosi tersebut umumnya dilakukan secara konvensional dengan penambahan zat inhibitor seperti oxygen scavenger atau senyawa organik jenis adsorpsi. Bilamana efektifitas kinerja inhibitor tersebut relatif rendah maka diperlukan jenis inhibitor altematif dengan kinerja yang lebih baik. Dalam penelitian ini dilakukan pengujian eksperimental terhadap suatu jenis inhibitor barn yaitu ekstrak campuran antara green tea (teh hijau) dengan kandungan utama epiga/lo cacethin gallate dan piper betle (daun sirih) dengan kandungan utama hydroxychavicol yang bersifat ramah lingkungan (green corrosion inhibitor).Penelitian bertujuan untuk menganalisis penurunan besaran laju korosi material baja (API 5L X52) di dalam lingkungan larutan 3,5 % NaCI teraerasi, pada kondisi aliran turbulen (0-5000 rpm) dengan penambahan inhibitor campuran ekstrak piper betle dengan green tea sehingga dapat dievaluasi effisiensinya. Selain itu dilakukan pula analisis serta sintesis terhadap mekanisme inhibisi elektrokimia ekstrak campuran inhibitor tersebut.Metoda pengukuran laju korosi dilakukan dengan menggunakan simulasi Rotating Cylinder Electrode (RCE) serta pengukuran elektrokimia kurva polarisasi. Mekanisme korosi diteliti dengan metoda Electrochemical Impedance Spectroscopy (EIS). Sedangkan karakterisasi ekstrak green inhibitor dilakukan dengan menggunakan metoda Fourier Transform Infra Red (FTIR).Hasil penelitian menunjukkan bahwa laju korosi material baja API 5L X52 di dalam larutan 3,5 % NaCl meningkat secara tajam hingga 195 mpy atau 5 mm/tahun pada 5000 rpm tanpa penambahan inhibitor. Sebagai pembanding, penggunaan inhibitor oxygen scavenger yang berupa senyawa sodium sulfit dapat menurunkan laju korosi dengan effisiensi inhibitor > 90 %. Pada konsentrasi campuran green inhibitor I 000 ppm piper betle + 4000 ppm green tea, effisiensi inhibitor dapat mencapai ±90 %. Inhibitor korosi tersebut berpengaruh terhadap kurva polarisasi anodik mapun katodik sehingga dapat berperan sebagai mixed inhibitor. Pengujian EIS menunjukkan pada kondisi turbulen dengan penambahan inhibitor, proses korosi dikontrol oleh mekanisme aktivasi yang ditunjukkan oleh adanya impedansi kapasitif. Pengujian FTIR menunjukkan adanya gugus-gugus fungsi ikatan kimia yaitu: hydroxyl phenolic, C=O dan alkena =CH2 yang berkombinasi sebagai pembentuk lapisan (film- forming).Pada kondisi 3,5% NaCI dengan tekanan gas C02 sebesar I atmosfir dan keadaan stagnan, dengan penambahan konsentrasi ekstrak campuran inhibitor I 000 ppm piper betle + 4000 ppm green tea, effisiensi inhibitor yang diperoleh adalah sebesar ± 74 %. Sintesis lapisan inhibisi campuran ekstrak green tea dengan piper betle ditunjukkan dengan usulan model lapisan yang bekerja secara sinergis antara karakteristik sifat-sifat: adsorpsi, antioxidant dan hydrophobic.

---

The corrosion rate of type API 5L X52 steel in 3.5% NaCl aerated solution under turbulent flow condition is relatively high (can reach more than 2 mrnlyear). Method to reduce the rate of corrosion is generally done conventionally by the addition of corrosion inhibitor substance such as oxygen scavenger or adsorption of organic compounds. In case of the effectiveness of inhibitor performance is low then types of alternative inhibitors with better performance are required. This study was carried out dealing with experimental testing of a new inhibitor type i.e. a mixture extracts of green tea with the main content epiga/lo cacethin gallate (EGCG) and piper betle with the main content hydroxychavicol which were classified as environmentally friendly inhibitor (green corrosion inhibitor).The purpose of this study was to analyze the decreasing of corrosion rate of type API 5L X52 steel in aerated 3.5% NaCl solution under turbulent flow conditions (0-5000 rpm). The effect of green inhibitor addition in the solution was observed and its inhibitor efficiency was evaluated. Moreover, analysis as well as synthesis of the electrochemical inhibition mechanism of the extract mixture of these inhibitors was performed.Corrosion rate measurement method was conducted by using a simulation of the Rotating Cylinder Electrode (RCE) and by electrochemical measurements of polarization curves. Corrosion mechanism was examined by Electrochemical Impedance Spectroscopy (EIS) while the characterization of green inhibitor material was carried out using the method of Fourier Transform Infra-Red (FTIR).The results showed that the corrosion rate of type API 5L X52 steel in 3.5% NaCl aerated solution increased sharply up to 195 mpy (5 mm/year) at 5000 rpm without the addition of corrosion inhibitor. As a comparison, the use of inhibitor of type oxygen scavenger using sodium sulfite compound decreased the corrosion rate with inhibitor efficiency > 90%. The addition of green inhibitor concentration of 1000 ppm piper betle + 4000 ppm green tea resulted in approximately 90% inhibitor efficiency. The green inhibitor affected the cathodic as well as the anodic polarization curves which were known as mixed corrosion inhibitor type. EIS testing showed that under turbulent conditions with the addition of corrosion inhibitor, the processes were controlled by an activation mechanism which indicated by the presence of capacitive impedance. The type of chemical bonds on the steel surface layer was analyzed by FTIR method which indicated the presence of function groups : phenolic hydroxyl, C=O and alkene C=CH2 which combined as film forming.In a solution containing 3,5 % NaCl with I atm C02 gas pressure and stagnant condition, the addition of 1000 ppm piper betle + 4000 ppm green tea extracts resulted in approximately 74% inhibitor efficiency. Synthesis of inhibition layer created by a mixture of extracts of green tea and piper betle was proposed which had several characteristics : adsorption, antioxidant and hydrophobic which were believed to have a synergistic effect."

"Pada proses pre-commisioning jaringan pipa bawah laut diperlukan pencegahan korosi dimana laju korosi material baja API 5L grade B di dalam larutan 3,5 % NaCl teraerasi pada kondisi steady masih relatif tinggi yang dapat mencapai lebih dari 20 mpy (0,5 mm/tahun). Upaya pencegahan korosi pada saat proses hydrotest dengan media air laut dilakukan dengan penambahan inhibitor anorganik yang mengandung zat corrosion inhibitor, oxygen scavenger dan biocide sehingga diperlukan bahan organik alternatif ramah lingkungan dengan kinerja yang lebih baik. Tujuan utama dari penelitian ini adalah untuk menginvestigasi efisiensi dari penggunaan campuran ekstrak sarang semut dan sirih merah sebagai alternatif inhibitor ramah lingkungan atau bahan campuran untuk mengurangi penggunaan inhibitor anorganik pada perlindungan korosi material baja API 5L Grade B dalam lingkungan 3,5% NaCl.Kemampuan inhibisi korosi dari hasil ekstrak bahan alami diinvestigasi dengan menggunakan pengujian Tafel polarisasi dan Electrochemical Impedance Spectroscopy (EIS) serta diverifikasi dengan pengujian kehilangan berat. Kandungan senyawa aktif dalam ekstrak sarang semut dan sirih merah beserta senyawa teradsorpsi pada permukaan logam dan mekaniseme inhibisi elektrokimia diinvestigasi dengan pengujian EIS, FTIR dan model adsorpsi isoterm. Pada konsentrasi campuran green inhibitor 2ml sarang semut + 1ml sirih merah, effisiensi inhibitor dapat mencapai 73,66%. Pada penggunaan sebagai inhibitor campuran dengan inhibitor kimia pada konsentrasi campuran 1ml kimia + 2ml green inhibitor, dapat menurunkan laju korosi secara signifikan dari 0,42 mm/year menjadi 0,03 mm/year dengan efisiensi mencapai 93,15%. Inhibitor korosi tersebut berpengaruh terhadap kurva polarisasi anodik maupun katodik sehingga dapat berperan sebagai mixed inhibitor.Pengujian FTIR menunjukan adanya gugus-gugus fungsi ikatan kimia yang berkombinasi sebagai pembentuk lapisan (film forming) seperti Gugus hidroksil, karbonil, aromatik, alkane dan amina. Adsorpsi senyawa-senyawa terkandung dalam inhibitor sarang semut dan sirih merah pada permukaan logam terjadi spontan mengikuti Langmuir adsorpsi isoterm. Hasil ini sesuai dengan hipotesis awal bahwa ekstrak sarang semut dan sirih merah yang mengandung senyawa antioksidan dapat mencegah proses oksidasi pada permukaan logam sehingga akan mengurangi laju korosi.

---

During pre-commissioning of subsea pipeline are require corrosion prevention since the corrosion rate of steel material of API 5L grade B in 3.5% NaCl aerated solution under steady state condition is still relatively high (can reach more than 0,5 mm/year). Method to prevent the corrosion during subsea pipeline hydrotest using seawater is generally by the addition of inorganic inhibitor containing corrosion inhibitor agent, oxygen scavenger and biocide, so that require to find out the alternative eco- friendly materials with better performance. The main objective of this study is to investigate the efficiency of the use of mixture of extract of myrmecodia pendans and piper crocatum as an alternative of eco-friendly inhibitor or a compound for reducing the use of inorganic inhibitors for corrosion protection of steel material API 5L Grade B in 3,5% NaCl Environmental.

The corrosion inhibition ability of natural ingredient extraction are investigated by using tafel polarization test and electrochemical impedance spectroscopy (EIS) and verified by weight loss test. The content of the active compounds in the extract of Myrmecodia Pendans and Piper Crocatum along with adsorption compound on metal surfaces and electrochemical inhibition mekaniseme are investigated by EIS, FTIR testing and model of the Langmuir adsorption isotherm. The addition of mixed green inhibitor concentration of 2ml myrmecodia pendans and 1ml piper crocatum is resulted in approximately 73.66% inhibitor efficiency while the addition of mixed green inhibitor into chemical inhibitor with concentration of 1ml for chemical and 2ml for green inhibitor are significantly reduce the corrosion rate from 0.42 mm/year to be 0.03 mm/year with approximately 93.15% inhibitor efficiency.

The green inhibitor affected the cathodic as well as the anodic polarization curves which were known as mixed corrosion inhibitor type. The type of chemical bonds on the steel surface layer was analyzed by FTIR method which indicated hydroxyl, carbonyl, aromatic, alkane and amine group. The adsorption of compounds contained in the myrmecodia pendans and piper crocatum inhibitor on a metal surface are occur spontaneously follows the Langmuir adsorption isotherm. These results are consistent with the initial hypothesis that the extract of myrmecodia pendans and piper crocatum contains antioxidant compound which can prevent the oxidation process in the metal surface thereby will reducing the corrosion rate."

"ABSTRAKKorosi merupakan suatu proses degradasi material akibat interaksi denganlingkungannya. Inhibitor korosi merupakan suatu zat yang dapat menghambatproses korosi. Bahan organik dipilih sebagai alternatif karena bersifat aman,mudah didapatkan, bersifat biodegradable, biaya murah, dan ramah lingkungan.Penelitian ini merupakan studi tentang inhibitor korosi menggunakan senyawaorganik yang dilakukan pada material baja API 5L di lingkungan larutan NaCl3,5%. Penelitian ini dilakukan untuk mempelajari efek penggunaan campuranekstrak daun sirsak dan ubi ungu sebagai inhibitor korosi dengan variasikonsentrasi. Ekstrak daun sirsak dan ubi ungu dipilih sebagai inhibitor korosikarena mengandung senyawa antioksidan yang dapat menghambat laju korosi.Pengukuran laju korosi dilakukan dengan menggunakan metode kehilangan beratdan polarisasi. Mekanisme terjadinya korosi diuji dengan menggunakanElectrochemical Impedance Spectroscopy (EIS) sementara karakterisasi darimaterial inhibitor organik dilakukan dengan menggunakan metode FourierTransform Infra-Red (FTIR). Tipe ikatan kimia yang terbentuk di lapisanpermukaan baja dianalisa dengan metode FTIR yang mengindikasikan adanyagugus fungsi karbonil (C=O) dan hidroksil (O-H) yang berkombinasi membentuksuatu lapisan. Di dalam larutan 100 mL NaCl 3,5%, penambahan ekstrak daunsirsak sebanyak 1 mL menghasilkan efisiensi inhibitor sekitar 73,38% (melaluipengujian polarisasi) dan di dalam larutan 520 mL NaCl 3,5%, penambahanekstrak daun sirsak sebanyak 1 mL menghasilkan efisiensi inhibitor sekitar 50%(melalui pengujian kehilangan berat). Kemudian, penambahan ekstrak ubi ungusebanyak 1-5 mL menyebabkan terjadinya penurunan efisiensi inhibitor. Ekstrakdaun sirsak dan ubi ungu bekerja dengan membentuk suatu lapisan tipis yangmengendap (adsorpsi) pada permukaan logam sebagai lapisan pelindung yangdapat menghambat reaksi logam tersebut dengan lingkungannya. Mekanisme inijuga didukung dengan meningkatnya nilai tahanan polarisasi dari permukaan bajasetelah ditambahkan inhibitor.

---

ABSTRACTCorrosion is a degradation of the material due to its interaction with theenvironment. Corrosion inhibitor is a substance that can inhibit the corrosionprocess. The use of organic corrosion inhibitor become a new alternative toachieve that goal, it happen because the organic corrosion inhibitor is safe, cheap,biodegradable, and environmentally friendly. This research is the study ofcorrosion inhibitor using organic compounds for API 5L steel in 3.5% NaClsolution. This research was conducted to study the use of mixture of annonamuricata leaves and purple sweet potato extracts as corrosion inhibitor withvariable concentration. Annona muricata leaves and purple sweet potato extractsare selected as corrosion inhibitor because they contain antioxidant compoundsthat can inhibit the corrosion rate. Corrosion rate measurement method wasconducted by using the weight loss and polarization methods. Corrosionmechanism was examined by Electrochemical Impedance Spectroscopy (EIS)while the characterization of organic inhibitor material was carried out using themethod of Fourier Transform Infra-Red (FTIR). The type of chemical bonds onthe steel surface layer was analyzed by FTIR method which indicated the presenceof functional groups carbonyl (C=O) and hydroxyl (O-H) which combined as filmforming. In a solution containing 100 mL 3.5% NaCl, the addition of 1 mLannona muricata leaves extract resulted in approximately 73.38% inhibitorefficiency (using the polarization method) and in a solution containing 520 mL3.5% NaCl, the addition of 1 mL annona muricata leaves extract resulted inapproximately 50% inhibitor efficiency (using the weight loss method). Then, theaddition of 1-5 mL purple sweet potato extract resulted the decreasing of inhibitorefficiency. Annona muricata leaves and purple sweet potato extracts work byforming a thin layer which settles (adsorption) to metal surfaces as a protectivelayer that can inhibit the reaction of the metal with its environment. Thismechanism is also supported by the increased value of the polarization resistanceof the steel surface after addition of inhibitor."

"Penelitian ini dilakukan untuk mempelajari mekanisme ekstrak kunyit putih Curcuma Zedoaria dan ekstrak ubi jalar ungu Ipomoea Batatas sebagai inhibitor korosi ramah lingkungan untuk API 5L pada lingkungan 3,5 NaCl. Karakterisasi kedua inhibitor dilakukan dengan pengujian FTIR dan menunjukkan bahwa senyawa yang terdapat pada kedua inhibitor tersebut adalah senyawa flavonoid. Pengujian polarisasi potensiodinamik dan EIS dengan variasi penambahan inhibitor serta campuran antara kedua inhibitor dilakukan untuk mempelajari sifat inhibisi, dari penelitian ini dapat diketahui bahwa masing ndash; masing kedua inhibitor dapat digunakan sebagai inhibitor ramah lingkungan untuk logam API 5L pada lingkungan 3,5 NaCl sedangkan campuran antara kedua inhibitor tersebut tidak dapat melindungi logam API 5L pada lingkungan 3,5 NaCl. Dari pengujian polarisasi potensiodinamik menunjukkan bahwa dengan penambahan konsentrasi inhibitor ekstrak kunyit putih maka laju korosi akan semakin menurun dan nilai efisiensi inhibisi semakin naik dengan nilai tertinggi adalah 70,5 , sedangkan dengan penambahan konsentrasi inhibitor ekstrak ubi jalar ungu laju korosi semakin turun dengan nilai efisiensi inhibisi maksimal sebesar 15,09. Namun hasil pengujian polarisasi potensiodinamik untuk inhibitor ekstrak kunyit putih 400 ppm yang ditambah dengan ekstrak ubi jalr ungu menunjukkan nilai laju korosi yang semakin meningkat. Hasil pengujian EIS menunjukkan bahwa kedua inhibitor ini dapat melindungi logam dengan membentuk sebuah lapisan film yang melapisi permukaan logam. Mekanisme adsorpsi inhibitor menunjukkan sebagai mekanisme adsorpsi secara fisik dan kimia serta sesuai dengan model dari Langmuir.

---

This study was conducted to study the mechanism of white turmeric extract Curcuma Zedoaria and purple sweet potato extract Ipomoea Batatas as a green corrosion inhibitor for API 5L in a 3.5 NaCl environment. The characterization of both inhibitors was done by FTIR testing and showed that the compounds present in both inhibitors were flavonoids. Potentiodynamic polarization and EIS polarization with variation of inhibitor addition and mixture of both inhibitors were performed to study the inhibitory properties, from this study it can be seen that each of the two inhibitors can be used as a green corrosion inhibitor for API 5L metal in a 3.5 NaCl environment whereas the mixture between the two inhibitors can not protect the 5L API in the 3.5 NaCl environment.

From potentiodynamic polarization testing showed that with the addition of white turmeric extract inhibitor concentration, the corrosion rate will decrease and the value of inhibition efficiency increases with the highest value is 70,5 , whereas with the addition of purple sweet potato extract inhibitor concentration decreasing with efficiency value maximum inhibition of 15.09.

However, potentiodinamic polarization test results for a 400 ppm white turmeric extract inhibitor added with purple java extract showed an increasing rate of corrosion rate. The results of the EIS test show that these two inhibitors can protect the metal by forming a film coating that coats the metal surface. The mechanism of adsorption inhibitor shows as a physical and chemical adsorption mechanism and is in accordance with the model of Langmuir. "

"Indonesia memiliki potensi cengkeh yang melimpah,daunnya dapat gugur setiap minggunya 0.96 kg/pohon. Inhibitor yang digunakan adalah ekstrak daun cengkeh dengan konsentrasi 1ml,2ml,3ml,4ml,5ml dan minyak cengkeh dengan konsentrasi 2ml,4ml,6ml,8ml,10ml. Pengujian dilakukan dengan metode linear polarisasi, Fourier Transform Infrared Spectroscopy ( FTIR ), Gas Chromatography Mass Spectroscopy ( GCMS ), dan Eletrochemical Impedance Spectroscopy ( EIS ). Konsentrasi optimum pada ekstrak daun cengkeh berada pada konsentrasi 4 ml dengan laju korosi 0.042 mm/year dan efisiensi 46.6 % sedangkan minyak cengkeh konsentrasi optimumnya berada pada konsentrasi 8 ml dengan laju korosi 0.001 mm/year dengan efisiensi 98.6 %. FTIR menunjukkan gugus - gugus fungsi yang berada di dalam inhibitor dan diperkuat dengan hasil GCMS untuk mengetahui senyawa aktif yang berada dalam inhibitor. Pengujian FTIR juga menunjukkan bahwa gugus - gugus fungsi pada inhibitor menempel pada permukaan sampel ketika sampel di rendam. Mekanisme adsorpsi dari kedua inhibitor adalah physical adsorption dengan nilai ΔGads pada inhibitor ekstrak daun cengkeh sebesar -7.575 kJ/mol, dan - 12.142 kJ/mol untuk inhibitor minyak cengkeh. EIS menunjukkan adanya peningkatan nilai tahanan charge transfer pada setiap kenaikan konsentrasi inhibitor dan nilai dari Cdl menurun yang menunjukkan bahwa terjadi pembentukan lapisan protektif. Nilai charge transfer dari inhibitor minyak cengkeh lebih besar yang berarti minyak cengkeh memiliki kemampuan inhibisi lebih baik dan ini diperkuat dari hasil polarisasi. Kedua jenis inhibitor ini termasuk dalam jenis inhibitor campuran (mix type inhibitor).

---

Indonesia has abundant potential clove, leaves can fall every week 0.96 kg/tree. Inhibitor which used on this research are clove leave extract with concentration 1ml,2ml,3ml,4ml,5ml and clove oil with concentration 2ml,4ml,6ml,8ml,10ml. Inhibitor are examined by linear polarization, Fourier Transform Infrared Spectroscopy ( FTIR ), Gas Chromatography Mass Spectroscopy ( GCMS ), and Electrochemical Impedance Spectroscopy ( EIS ). The result show that optimum concentration of clove leave extract is at 4 ml with corrosion rate 0.042 mm/year and efficiency 46.6% where as optimum concentration of clove oil is at 8 ml with corrosion rate 0.001 mm/year and efficiency 98.6 %. FTIR obtain functional group which contained in inhibitor and GCMS result also show active compound in inhibitor. FTIR show that functional group in inhibitor adsorp on the metal surface when sample is soaked in inhibitor. Adsorption mechanism of these inhibitor is physical adsorption with ΔGads of clove leave extract inhibitor is -7.575 kJ/mol, and - 12.142 kJ/mol for clove oil inhibitor. EIS show increasing charge transfer resistance with increasing inhibitor concentration and decreasing Cdl also show there are protective film forming. The charge transfer resistance of clove oil inhibitor higher, means clove oil has better inhibition than clove leaves extract. Both of these inhibitor are included in mix type inhibitor."

"Kemampuan inhibisi korosi senyawa fenolik minyak zaitun pada baja API 5L Grade B di lingkungan NaCl 3,5 % diinvestigasi dengan menggunakan pengujian Tafel polarisasi dan Electrochemical Impedance Spectroscopy (EIS). Senyawa fenolik minyak zaitun yang berperan dalam menginhibisi korosi diinvestigasi dengan pengujian FTIR. Senyawa oleuropein dalam minyak zaitun berperan dalam menginhibisi korosi pada sistem dengan tipe mixed inhibitor. Efisiensi inhibisi optimal terjadi pada konsentrasi 1 ml minyak zaitun/100 ml NaCl. Efisiensi inhibisi akan menurun seiring dengan kenaikan temperatur. Senyawa oleuropein menginhibisi korosi dengan cara adsorpsi fisika (interaksi elektrostatis) pada permukaan logam membentuk lapisan tunggal yang akan menghambat transfer muatan dan massa. Adsorpsi senyawa fenolik minyak zaitun pada permukaan logam terjadi spontan mengikuti Langmuir adsorpsi isoterm. Adsorpsi senyawa fenolik minyak zaitun akan meningkatkan energi aktivasi proses korosi. Hasil pengujian menunjukkan bahwa senyawa fenolik minyak zaitun dapat digunakan sebagai alternatif inhibitor ramah lingkungan pada baja API 5L Grade B di lingkungan NaCl 3,5 %.

---

Corrosion inhibition ability of olive oil phenolic compounds on API 5L Grade B steel in 3.5% NaCl environment was investigated using Tafel polarization and Electrochemical Impedance Spectroscopy (EIS) test. Olive oil phenolic compounds that acts for inhibit corrosion process was investigated by FTIR test. Oleuropein compounds in olive oil acts for inhibit corrosion process in the system with mixed type inhibitors. Optimal inhibition efficiency occurs at a concentration 1 ml olive oil/100 ml NaCl. Inhibition efficiency decreases with increasing temperature. Oleuropein compounds inhibit corrosion by physisorption (electrostatic interactions) on the metal surface to form a single layer that will inhibit the charge and mass transfer. Adsorption of olive oil phenolic compounds on the metal surface occurs spontaneously follow the Langmuir adsorption isotherm. Adsorption of olive oil phenolic compounds will increase the activation energy of the corrosion process. The results showed that olive oil phenolic compounds can be used as an alternative green corrosion inhibitor on API 5L Grade B steel in 3.5% NaCl environment."

"Ekstrak kubis merah telah dievaluasi sebagai inhibitor korosi ramah lingkungan untuk baja API 5L grade X60 dilingkungan larutan NaCl 3,5% menggunakan metode Tafel polarisasi dan Electrochemical Impedance Spectroscopy. Pengujian Tafel Polarisasi menunjukkan ekstrak kubis merah bertindak sebagai inhibitor campuran sedangkan pengujian Electrochemical Impedance Spectroscopy menunjukkan terbentuknya lapisan film dari molekul inhibitor pada permukaan baja API 5L grade X60, dari kedua pengujian ini effisiensi inhibisi meningkat dengan meningkatnya jumlah konsentrasi inhibitor yang ditambahkan. Hasil evaluasi menunjukkan bahwa molekul inhibitor teradsorpsi secara fisika dengan mengikuti model adsorpsi Langmuir Isoterm, senyawa Cyanidin diketahui sebagai senyawa utama yang teradsorpsi pada permukaan baja API 5L grade X60.

---

Red cabbage extract has been evaluated as green inhibitor corrosion for API 5L grade X60 steel on 3.5% NaCl environment using Tafel polarization and Electrochemical Impedance Spectroscopy. Tafel polarization methode shows red cabbage extract acts as an mixed inhibitor and Electrochemical Impedance Spectroscopy methode showed the formation of a layer of film of the inhibitors molecule on the surface of the API 5L grade X60 steel, from both this methode inhibition efficiency increases with increasing concentration of inhibitor. Results of the evaluation showed that the inhibitor molecules is physically adsorbed by following the Langmuir isotherms model, cyanidin compounds are known as major compounds are adsorbed on the surface of API 5L grade X60 steel."

"Tesis ini mempelajari mengenai pengaruh injeksi ekstrak Andaliman dan Alpha-Tocopherol sebagai green corrosion inhibitor pada baja API 5L dalam larutan HCl 1M. Dengan pengujian weight loss diperlihatkan bahwa inhibitor campuran antara ekstrak Andaliman dan Alpha-Tocopherol mampu menurunkan laju korosi dengan efisiensi 92.07 pada konsentrasi inhibitor 2 ml Andaliman 0.5 ml Alpha-Tocopherol. Dari pengujian polarisasi ditunjukkan bahwa inhibitor campuran antara ekstrak Andaliman dan Alpha-Tocopherol menggeser kurva polarisasi kearah atodik dan katodik mixed type inhibitor , yang menunjukkan ciri utama sebagai inhibitor dari bahan organik. Pengujian dengan FTIR dan GCMS memperkuat dugaan bahwa inhibitor ekstrak Andaliman dan Alpha-Tocopherol sebagai inhibitor adsorpsi/film forming.

---

This thesis is intended to study the influences of Andaliman extract and Alpha- Tocopherol injection as green corrosion inhibitor for API 5L steel in HCl 1M solution. By weight loss analysis, it show that mixed inhibitor from andaliman extract and Alpha-Tocopherol can reduce corrosion rate with efficiency up to 92.07 % under inhibitor injection about 2 ml Andaliman + 0.5 ml Alpha- Tocopherol. By polarization, it is shown that inhibitor shift polarisation curves for both of anodic and cathodic polarisation (mixed type inhibitor), shows that inhibitor have characteristic as inhibitor from organic material. By FTIR and GCMS analysis can be concluded that inhibitor from Andaliman and A- Tocopherol act inhibition by adsorption/film forming corrosion inhibitor."

"

Penelitian ini dilakukan untuk mempelajari mekanisme ekstrak daun kelor (Moringa Oleifera) dan ekstrak ubi ungu (Ipomoea Batatas) sebagai inhibitor korosi ramah lingkungan untuk API 5L pada lingkungan 0,2 M HCl. Karakterisasi kedua inhibitor dilakukan dengan pengujian FTIR dan menunjukkan bahwa senyawa yang terdapat pada kedua inhibitor tersebut adalah senyawa flavonoid. Pengujian polarisasi potensiodinamik dan EIS dengan variasi penambahan inhibitor serta campuran antara kedua inhibitor dilakukan untuk mempelajari sifat inhibisi, dari penelitian ini dapat diketahui bahwa masing- masing kedua inhibitor dapat digunakan sebagai inhibitor ramah lingkungan sedangkan campuran antara kedua inhibitor tersebut tidak dapat melindungi logam API 5L pada lingkungan 0,2 M HCl. Dari pengujian polarisasi potensiodinamik menunjukkan bahwa dengan penambahan konsentrasi inhibitor ekstrak daun kelor maka laju korosi akan semakin menurun dan nilai efisiensi inhibisi semakin naik dengan nilai tertinggi adalah 73,08%, sedangkan dengan penambahan konsentrasi inhibitor ekstrak ubi ungu laju korosi semakin turun dengan nilai efisiensi inhibisi maksimal sebesar 65,31%. Namun hasil pengujian polarisasi potensiodinamik untuk kombinasi kedua inhibitor menunjukkan nilai laju korosi yang semakin meningkat. Hasil pengujian EIS menunjukkan bahwa kedua inhibitor ini dapat melindungi logam dengan membentuk sebuah lapisan film yang melapisi permukaan logam. Mekanisme adsorpsi inhibitor menunjukkan sebagai mekanisme adsorpsi secara fisik serta sesuai dengan model dari Langmuir untuk inhibitor ekstrak daun kelor dan Temkin untuk ekstrak ubi ungu.

---

This research was conducted to study the mechanism of Moringa Oleifera leaf extract and purple sweet potato extract (Ipomoea Batatas) as green corrosion inhibitors for API 5L in the environment of 0.2 M HCl. The characterization of the two inhibitors was carried out by FTIR testing and showed that the compounds contained in the two inhibitors were flavonoids. Testing of potentiodynamic polarization and EIS with variations in inhibitor addition and mixtures between the two inhibitors was carried out to study the inhibitory properties, from this study it can be seen that each of the two inhibitors can be used as green corrosion inhibitors while the mixture between the two inhibitors cannot protect the API 5L environment of 0.2 M HCl. From the potentiodynamic polarization test showed that by increasing the concentration of Moringa leaf extract inhibitors, the corrosion rate will decrease and the inhibition efficiency value increases with the highest value is 73.08%, whereas with the addition of the purple yam extract inhibitor concentration the corrosion rate decreases with the inhibition efficiency value maximum of 65.31%. However, the results of the potentiodynamic polarization test for the combination of the two inhibitors showed an increasing corrosion rate. The EIS test results show that these two inhibitors can protect the metal by forming a layer of film that lines the metal surface. The adsorption inhibitor mechanism shows as a mechanism of physical adsorption and in accordance with the model from Langmuir for Moringa leaf extract inhibitors and Temkin for purple sweet potato extract.

"

"Teknik Metalurgi dan MaterialJudul : Studi Ketahanan Korosi Pipa Baja API 5L X42 dengan Green Inhibitor Ekstrak Bawang Dayak Eleutherine americanna Merr. dalam Lingkungan 1M HCl. Ketahanan korosi pipa baja API 5L X42 dengan inhibitor ramah lingkungan ekstrak bawang dayak Eleutherine americanna Merr. dalam lingkungan 1M HCl diinvestigasi dengan pengujian polarisasi tafel, weight loss, dan Electrochemical Impedance Spectroscopy EIS . Senyawa flavonoid yang bersifat antioksidan yang berperan untuk menginhibisi korosi diinvestigasi melalui pengujian FTIR. Variabel yang digunakan adalah konsentrasi inhibitor, yaitu 0 ppm, 100 ppm, 250 ppm, 500 ppm, dan 1000 ppm. Ekstrak bawang dayak yang mempunyai gugus flavonoid merupakan inhibitor jenis campuran, dan dominan katodik. Efisiensi inhibisi paling tinggi didapatkan dengan konsentrasi 1000 ppm. Inhibitor ekstrak bawang dayak dapat digunakan sebagai alternatif inhibitor ramah lingkungan untuk baja API 5L X42 pada lingkungan 1M HCl.

---

Metallurgy and Materials EngineeringTitle Study of Corrosion Resistance of Pipeline API 5L X42 Using Green Inhibitor Bawang Dayak Eleutherine americanna Merr. in 1M HCl. This study aimed to investigate the ability of Eleutherine americanna Merr. extract as an environment friendly inhibitor for API 5L X42 in 1M HCl. Corrosion inhibition ability of this extract was tested using tafel polarization, weight loss and electrochemical impedance spectroscopy methods. FTIR test was used to investigate flavonoid and antioxidant compound that plays an important role to inhibit corrosion. In this study the concentration of Eleutherine americanna Merr. extract used was 0 ppm, 100 ppm, 250 ppm, 500 ppm, and 1000 ppm. It can be concluded that Eleutherine americanna Mer. extract can be used as an alternative and environmental friendly inhibitor for API 5L X42 in 1M HCl. "