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"Perilaku korosi logam Pb murni di dalam larutan H2SO4 dengan penambahan variasi PbNO3 dikarakterisasi pada penelitian ini. Metode linear sweep voltammetry (LSV) menunjukkan proses selama elektrolisis di dalam larutan 0,5 M H2SO4. Dengan adanya penambahan PbNO3 ternyata mampu meningkatkan ketahanan korosif dari logam timbal murni. Sehingga dapat menyiratkan bahwa terjadi penekanan pelarutan logam dan reduksi oksigen. Dari analisis X-ray difrractometer (XRD) mengungkapkan adanya perbedaan fasa setelah proses elektrolisis, dimana pembentukan PbSO4 yang relatif tinggi akan mempengaruhi ketahanan korosi dari logam timbal. Untuk mengevaluasi morfologi permukaan logam timbal dilakukan dengan teknik scanning electron microscope (SEM). Analisis permukaan menunjukkan bahwa sampel dengan kandungan PbSO4 berlebih akan mengalami tingkat kekasaran yang cukup parah.

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The pure Pb metal corrosion behavior in H2SO4 solution added with PbNO3 was characterized in this study. The linear sweep voltammetry (LSV) method demonstrated the electrolysis process in a 0,5 M H2SO4 solution. The PbNO3 addition improved the corrosive resistance of pure lead metal. Therefore, it indicates that metal solubility suppression and oxygen reduction occurred. The X-ray diffractometer (XRD) analysis revealed phase differences post-electrolysis, where relatively high PbSO4 production will affect the corrosion resistance of the lead metal. The scanning electron microscope (SEM) technique was employed to evaluate the lead metal surface morphology. The surface analysis showed that samples with excessive PbSO4 concentration experienced severe roughness levels."

"Benda uji paduan Alumunium seri 3104-H19 berbentuk lembaran sebagai bahan baku kemasan minuman kaleng, dilakukan uji korosi dengan metoda perendaman dalam larutan asam yaitu larutan korosif sesuai dengan ASTM G34, yaitu 4M NaCl + 0,5 M KNO3 + 0,1M HNO3. Bahan paduan Alumunium tersebut adalah 3104-H19 dengan kandungan unsur Titanium, Ti yang berbeda yaitu 0,013 % berat 0.010 % berat dan 0%.Dalam pengujian ini diamati bentuk korosi yang terjadi dan besarnya laju korosi pada waktu perendaman dengan variasi waktu 1, 2, 3, 4 dan 5 hari. Serta divariasikan konsentrasi larutan korosif bahan perendaman, yaitu 4M NaCl; 2M NaCl, 5M NaCl dan 6M NaCl.Dari pengujian ini dapat diketahui bahwa makin banyak kandungan Ti pada paduan alumunium akan meningkatkan ketahanan korosinya dimana kandungan Ti 0,013% lebih baik dibandingkan 0,01% dan 0%.

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Specimen Alumunium alloy foil 3104 H19 as a raw material for beverages can, would be got corrosion test by immersing in acid solution according to ASTM G34, it was 4M NaCl + 0,5 M KNO3 + 0,1M HNO3. The material alumunium alloy 3104 H19 was having Titanium, Ti element with 0.013% of weight; 0.010 % of weight and 0%. This experiment would be observed for corrosion shape and rate of corrosion with variation of duration immersing, 1, 2, 3, 4 and 5 days. Also for variation of concentration of corrosive solution, 4M NaCl; 2M NaCl, 5M NaCl dan 6M NaCl.

By experiment, it was known that the more quantity of titanium element on the alloy, will enhance the corrosion resistance, which Ti 0.013% is better than 0.010% and 0%."

"Pipa baja API 5L Grade B merupakan jenis pipa yang banyak dipakai pada struktur anjungan untuk minyak bumi dan gas, dan umumnya banyak digunakan sebagai pipa penyalur gas, air, dan minyak. Instalasi sistem perpipaan dengan menggunakan pipa baja API 5L Grade B terutama di zona air laut perlu mendapatkan perhatian khusus karena instalasi sistem perpipaan pada zona ini rawan terhadap masalah korosi terutama di lingkungan air laut. Kandungan terbesar pada logam paduan API 5L Grade B adalah unsur besi (Fe) sebanyak 98,06 % berat sehingga paduan ini tergolong dalam kelompok baja carbon rendah. Dan komposisi utama penyebab korosi pada paduan baja API 5L Grade B ini sangat didominasi unsur  carbon (C), oksigen (O), dan unsur chlor (Cl) yang ada di zona air laut dengan produk korosi adalah fasa FeCl₂ (lawrencite), FeO₂ (lepidocrosite), Fe₂O₃ (hematite), dan Fe₃O₄ (magnetite). Laju korosi tertinggi diperoleh pada sampel API 5L Grade B yang diletakkan di dalam lingkungan pantai yaitu sebesar 20.84 mpy pada saat pasang, sedangkan laju korosi tertinggi pada saat surut terjadi pada sampel API 5L Grade B yaitu sebesar 12.14 mpy yang diletakkan di lingkungan air payau. Bentuk korosi yang terjadi meliputi tiga tahapan korosi, yaitu pada awalnya terjadi korosi seragam yaitu suatu bentuk korosi elektrokimia yang terjadi dengan tingkat ekuivalen tinggi pada seluruh bagian permukaan yang diuji dan sering kali meninggalkan suatu kerak dibalik permukaan atau endapan. Kemudian dengan meningkatnya laju korosi dan factor lingkungan korosi menyerang daerah celah, sehingga terbentuk korosi celah (crevice corrosion) dibatasi hanya untuk serangan terhadap paduan-paduan yang oksidanya terpasifkan oleh ion-ion agresif seperti klorida dalam celah-celah atau daerah-daerah permukaan logam yang tersembunyi dan pada akhirnya membentuk korosi sumuran (pitting corrosion).

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Steel pipe of API 5L Grade B is a type of pipe that is widely used in bridge structures for oil and gas, and generally widely used as gas, water, and oil pipelines. Installation of piping systems using steel pipe API 5L Grade B, especially in sea water zone needs special attention because of the installation of the piping system in this zone is prone to corrosion problems, especially in the marine environment. The content of the metal alloy largest API 5L Grade B is the element iron (Fe) around 98.06 wt% so that the alloy is classified in the group of low carbon steel. And the composition of the main causes of corrosion in steel alloys API 5L Grade B is dominated elements carbon (C), oxygen (O), and chlorine (Cl) in the zone of sea water with corrosion products are phases of FeCl₂ (lawrencite), FeO₂ (lepidocrosite), Fe₂O₃ (hematite) and Fe₃O₄ (magnetite). The highest corrosion rate was obtained on a sample of API 5L Grade B is placed in the beach environment is equal to 20.84 mpy at high tide, while the highest corrosion rate at low tide occurs in samples of API 5L Grade B is equal to 12:14 mpy placed in brackish water environments. Form of corrosion that occurs includes three stages of corrosion, the first is uniform corrosion namely a form of electrochemical corrosion that occurs with high equivalent level in all parts of the surface are tested and often leave behind a surface crust or sediment. Then by increasing the rate of corrosion and the environment factor, the corrosion attacked gap area, thus forming a crevice corrosion (crevice corrosion) which limited only to attacks on the oxide alloys by aggressive ions such as chloride in the gaps or areas of the metal surface hidden and eventually form the pitting corrosion (pitting corrosion)."

"Penelitian ini dilakukan untuk mempelajari laju korosi pada mild steel ST41 didalam larutan 0,5 M HCl dengan pemberian ekstrak buah Melastoma malabathricum L sebagai green corrosion inhibitor dengan variasi konsentrasi 0, 1000, 2000, 5000, dan 8000 ppm. Metode weight loss, polarisasi dan EIS (Electrochemical Impedance Spectroscopy) digunakan untuk mengukur laju korosi dan efisiensi inhibisi ekstrak Melastoma malabathricum L ini. Dari pengujian dengan infra merah (FTIR) dan scanning electron microscopy (SEM) terhadap sampel baja yang direndam didalam ekstrak melastoma malabathricum, diketahui bahwa lapisan inhibisi terbentuk pada permukaan sampel baja.Dari hasil pengujian polarisasi diketahui bahwa ekstrak melastoma malabathricum bersifat mixed-type inhibitor. Berdasarkan hasil dari weight loss, polarisasi, dan EIS, kemampuan inhibisi ekstrak buah melastoma malabathricum pada baja karbon dalam lingkungan 0,5 M HCl mengalami peningkatan yang ditunjukkan dengan menurunnya laju korosi, namun penurunan laju korosi dan efisiensi semakin berkurang dengan bertambahnya konsentrasi tertentu inhibitor. Efisiensi inhibisi terbaik adalah 88,071% pada 8000 ppm.

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This work was carried out to study the corrosion rate of mild steel ST41 in 0.5 M HCl solution using Melastoma malabathricum L fruit extract as green corrosion inhibitor at various extract concentrations of 0, 1000, 2000, 5000, and 8000 ppm. Weight loss, polarization and electrochemical impedance spectroscopy (EIS) were used to measure the corrosion rate and inhibition efficiency of this Melastoma malabathricum extract. The results from Fourier transform infra red (FTIR) and scanning electron microscopy (SEM) of steel samples immersed in the extract of melastoma malabathricum showed that an inhibitory layer was formed on the surface of the steel sample. The results of the polarization test revealed that the extract of melastoma malabathricum is a mixed-type inhibitor. Based on the results of weight loss, polarization, and EIS, the inhibitory ability of melastoma malabathricum fruit extract on medium carbon steel in an environment of 0.5 M HCl has increased as indicated by a decrease in the corrosion rate, but the decrease in the corrosion rate and the efficiency is reduced with the increase in certain inhibitor concentrations.The best inhibition efficiency was 88.071% at 8000 ppm."

"Mekanisme inhibisi korosi pada ekstrak biji saga Abrus precatorius pada baja API 5L Grade B dalam larutan 1M HCl telah dipelajari menggunakan metode polarisasi potensiodinamik dan Electrochemical Impedance EIS pada variasi konsentrasi 2 ml, 4 ml, 6 ml, 8 ml, dan 10 ml. Kandungan flavonoid diidentifikasi terdapat pada ekstrak biji saga melalui pengujian FTIR. Hasil penelitian menunjukkan bahwa kenaikan laju korosi menurun seiring dengan penambahan ekstrak biji saga. Ekstrak biji saga dapat berperan sebagai inhibitor korosi dengan efisiensi maksimum 86 pada pengujian polarisasi potensiodinamik dan 66 pada pengujian EIS. Ekstrak biji saga tergolong ke dalam inhibitor campuran dengan dominan inhibitor katodik. Adsorpsi dari ekstrak biji saga pada permukaan logam sesuai isoterm adsorpsi Langmuir dengan mekanisme adsorpsi fisika.

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Mechanism of corrosion inhibition on saga Abrus precatorius seed extract on API 5L Grade B in 1M HCl solution has been studied using potentiodynamic polarization and electrochemical impedance spectroscopy EIS with variation concentration of 2 ml, 4 ml, 6 ml, 8 ml, and 10 ml. Flavonoid content in saga seed was identified by FTIR.

The results showed corrosion rate increased with a decrease inhibitor concentration of saga seed extract. Saga seed extract acts as a corrosion inhibitor with maximum efficiency 86 using potentiodynamic polarization and 66 using EIS. Saga seed extract acts as mixed type inhibitor with cathodic inhibitor dominant. Adsorption of saga seed extract on metal surface obeyed Langmuir adsorption isotherm by physical adsorption mechanism."

"Paduan Aluminium Lithium ditargetkan menjadi advanced materials untuk industri dirgantara, karena memiliki densitas yang rendah, tahan korosi dan bersifat ringan. Paduan Aluminium lithium 2091 yang digunakan memiliki komposisi 94.87 wt% Al, 1.9 wt% Li dan 1.85 wt% Cu. Paduan ini digunakan sebagai material uji dan diberi heat treatment dan quenching dengan variasi waktu delay. Penelitian ini bertujuan untuk mencari hubungan antara delay quenching dengan sifat korosi aluminium lithium 2091. Aluminium lithium 2091 di solutionized pada temperatur 525°C selama 6 jam, lalu dilakukan proses quenching dengan media air pada temperatur ruang dengan variasi waktu delay mulai dari 0 detik, 30 detik, 60 detik dan 90 detik. Karakterisasi menggunakan X-Ray Diffraction bertujuan untuk mempelajari fasa pada masing-masing sampel. Sedangkan pengujian korosi dilakukan dengan alat potensiostat dengan metode Linear Sweep Voltammetry (LSV) dan Cyclic Voltammetry (CV). Pengujian korosi menggunakan larutan bioethanol dengan variasi temperatur. Hasilnya sampel tanpa delay quenching memiliki laju korosi paling kecil, yaitu sebesar 0.0465 mm/year. Sedangkan hasil pengujian Cyclic Voltammetry ialah dapat diketahui reaksi yang terjadi adalah reaksi irreversible, dibuktikan dengan selisih potensial yang menunjukkan nilai ≠ 0.0183 V (T = 5℃), ≠ 0.0197 V (T = 25℃) dan ≠ 0.0209 V (T = 43℃).

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Aluminum Lithium is targeted to be advanced materials for the aerospace industry, because it has a low density, good corrosion resistance and lightweight. Aluminum lithium 2091 has a composition of 94.87 wt% Al, 1.9 wt% Li and 1.85 wt% Cu. This alloy has been subjected to heat treatment and quenching with variations delay time. This study aims to find the relationship between delay quenching with the corrosion properties of aluminum lithium 2091. Aluminum lithium 2091 had solutionized at 525 °C for 6 hours and then have been quenched in water at room temperature with variations of delay time starting from 0 seconds, 30 seconds, 60 seconds and 90 seconds. Characterization using X-Ray Diffraction aims to study the phase in each sample. Meanwhile, corrosion testing was carried out using a potentiostat using the Linear Sweep Voltammetry (LSV) and Cyclic Voltammetry (CV) methods. Corrosion testing using bioethanol solution with temperature variations. The result show aluminium lithium 2091 without delay quenching has the lowest corrosion rate, which is 0.0465 mm/year. While the results of the Cyclic Voltammetry test are that it can be seen that the reaction that occurs is an irreversible reaction, as evidenced by the potential difference which shows the values of ΔE ≠ 0.0183 V (T = 5 ℃), ΔE ≠ 0.0197 V (T = 25 ℃) and ΔE ≠ 0.0209 V (T = 43 ℃)."

"Steel dengan menggunakan proses pengelasan GTAW terhadap kemampuan tahan korosi pitting SDSS pada lingkungan dengan konsentrasi klorida yang tinggi. Pengelasan dilakukan terhadap empat spesimen dengan gas pelindung yang berbeda, yaitu Ar UHP, Ar 2 N 2, Ar 5 N 2 dan Ar 10 N 2. Hasil lasan pada ke-empat spesimen akan dilakukan pengamatan struktur makro dan mikro dengan mikroskop optik dan SEM-EDS Scanning Electron Microscopic-Energy Dispersive X-ray Spectroscopy , serta pengujian kekerasan, ferite content, pengujian korosi pitting berdasarkan ASTM G48-11 Method E dan potentiodynamic anodic polarization berdasarkan ASTM G5-13 untuk melihat pengaruh nitrogen terhadap struktur mikro dan kemampuan tahan korosi pitting SDSS.

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This thesis focuses on the effect of nitrogen on the shielding gases for the welding of super duplex stainless steel materials by using GTAW welding process against the pitting corrosion resistance of SDSS in environment with high chloride concentration. Welding was carried out on four specimens with different shielding gases, Ar UHP, Ar 2 N 2, Ar 5 N 2 and Ar 10 N 2. The weldments of the four specimens will be observed for macro and microstructures with optical microscope and SEM EDS Scanning Electron Microscopic Energy Dispersive X ray Spectroscopy , hardness testing, ferrite content, pitting corrosion testing based on ASTM G48 11 Method E and potentiodynamic anodic polarization based on ASTM G5 13 to see the effect of nitrogen on the microstructure and pitting resistance of SDSS."

"Paduan aluminium AA7075-T7351 merupakan paduan keras yang memiliki keunggulan sifat mekanis, ringan, dan dapat di recycle sehingga paduan ini banyak di aplikasikan sebagai material struktur. Untuk meningkatkan ketahanan korosi paduan tersebut diperlukan rekayasa permukaan sehingga umur pakai material ini menjadi lebih lama dengan cara anodisasi. Optimasi ketahanan korosi dan kekerasan mekanik diperoleh dengan variasi suhu elektrolit dan penambahan aditif etanol pada elektrolit asam sulfat. Morfologi dan ketebalan lapisan oksida yang dihasilkan diamati dari foto SEM, ketahanan korosi sampel diuji dengan metode elektrokimia, dan karakteristik sifat mekanis permukaan didapat dari uji kekerasan. Anodisasi pada suhu 0°C mampu meningkatkan ketebalan lapisan oksida hingga 46%, kekerasan mikro sampai dengan 83%, dan meningkatkan ketahanan korosi. Anodisasi pada suhu 0°C dengan penambahan etanol 10 vol% dalam elektrolit asam sulfat pada paduan aluminium AA7075-T7351 menghasilkan lapisan oksida paling tebal (75,75µm), kekerasan mikro paling besar (281.06 HV), serta ketahanan korosi paling tinggi (Icorr = 10-5 µA/cm2).

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AA7075-T7351 aluminum alloy is a hard alloy that has the advantage of mechanical properties, lightweight, and can be recycled so that this alloy is widely applied as a structural material. To improve the corrosion resistance of these alloys, surface engineering is needed so that the lifetime of this material becomes longer by anodizing. Optimization of corrosion resistance and mechanical hardness is obtained by variations in electrolyte temperature and the addition of ethanol into sulfuric acid electrolytes. The morphology and thickness of the resulting oxide layer were observed from SEM photographs, the corrosion resistance of the samples was tested by electrochemical methods, and the characteristics of surface mechanical properties were obtained from hardness tests. Anodization at 0 ° C can increase the thickness of the oxide layer by up to 46%, micro hardness up to 83%, and increase corrosion resistance. Anodization at 0 ° C with the addition of 10 vol% ethanol in sulfuric acid electrolyte in aluminum alloy AA7075-T7351 resulted in the thickest oxide layer (75.75µm), the greatest micro hardness (281.06 HV), and the highest corrosion resistance (Icorr = 10-5 µA/cm2)."

"Provides a methodology for integrating materials selection with the design process, including simultaneous technical and economic evaluation. Save hours of frustrating research time: Get fast answers about the best material for a particular application.In the past, researching the endless sources on corrosion and materials in their countless applications were next to impossible. That's why this book was written: to help simplify your materials selection problems. It's an exhaustive source on the different corrosion-resistant materials, types of corrosion, factors affecting corrosion, passivation, corrosion monitoring, corrosion control measures, methodology of materials selection, and more."