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"Hidrogen merupakan suatu sumber energi alternatif ramah lingkungan yang memiliki potensi sangat besar untuk dikembangkan. Gas hidrogen dapat dihasilkan secara sederhana dengan metode elektrolisis. Pada penelitian ini menggunakan metode elektrolisis NaCl. Proses elektrolisis berlangsung selama 10 menit untuk setiap variasi tegangan listrik. Adapun variabel NaCl nya yaitu NaCl 0,5; 1; 1,5; 2; 2,5; dan 3 M, tegangan listrik 5, 8, 11, 14, 17, dan 20 V, dan variasi elektroda yang meliputi variasi 1 berbentuk potongan - potongan Stainless Steel 316, variasi 2 berbentuk batang Stainless Steel 316 bercabang tiga, dan variasi 3 berbentuk potongan - potongan Stainless Steel 316 – karbon aktif granular. Berdasarkan penelitian yang telah dilakukan membuktikan bahwa semakin tinggi konsentrasi NaCl dan tegangan listrik, maka semakin besar nilai kuat arus listrik, daya listrik, laju produksi gas hidrogen, nilai hambatan listriknya semakin kecil, dan nilai pH larutan elektrolitnya semakin besar yang menunjukkan adanya NaOH sebagai produk samping. Peningkatan daya listrik menyebabkan efisiensi energi sel elektrolisis menurun. Variasi elektroda terbaik yaitu variasi elektroda 2 yang berbentuk batang Stainless Steel 316 bercabang tiga dengan nilai hambatan listrik paling kecil sebesar 5,4216 Ω dan total laju produksi gas hidrogen yang dihasilkan paling besar sebesar 1,328 mL/s dengan yield sebesar 50% pada konsentrasi NaCl 2,5 M, serta menghasilkan nilai efisiensi energi sebesar 39%; 24%; 18%; 14%; 11% dan 10% pada masing – masing variasi tegangan listrik 5, 8, 11, 14, 17, dan 20 V, dengan tingkat kemurnian gas hidrogennya sebesar 97,54%.

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Hydrogen is an environmentally friendly alternative energy source that has enormous potential to be developed. Hydrogen gas can be produced simply by electrolysis method. In this research using the NaCl electrolysis method. The electrolysis process lasts for 10 minutes for each variation of the electric voltage. The NaCl variable are 0,5; 1; 1,5; 2; 2,5; and 3 M, the electric voltage variables are 5, 8, 11, 14, 17, and 20 V, and variations of the electrodes which include variation 1 in the form of 316 Stainless Steel pieces, variation 2 in the form of three-pronged 316 Stainless Steel rods, and variation 3 in the form of Stainless Steel 316 pieces – granular activated carbon. Based on the research that has been done, it proves that the higher the concentration of NaCl and the electric voltage, the greater the value of the electric current strength, electric power, the rate of production of hydrogen gas, the smaller the value of the electrical resistance, and the greater the pH value of the electrolyte solution which indicates the presence of NaOH as a side product. The increase in electric power causes the energy efficiency of the electrolytic cell to decrease. The best electrode variation is the variation of electrode 2 which is in the form of a three-pronged Stainless Steel 316 rod with the smallest electrical resistance value of 5,4216 Ω and the highest total production rate of hydrogen gas produced is 1,328 mL/s with a yield of 50% at 2,5 M NaCl concentration, and produces an energy efficiency value of 39%; 24%; 18%; 14%; 11% and 10% for each variation of electric voltage 5, 8, 11, 14, 17, and 20 V, with a purity level of hydrogen gas of 97,54%."

"Gas hidrogen merupakan bahan bakar hijau yang ramah lingkungan karena proses pembakarannya yang tidak menghasilkan gas karbon dioksida (CO2). Di sisi lain, kebutuhan oksigen untuk menangani pasien khusus harus tersedia secara instan. Ketersediaan gas hidrogen harus diproduksi dengan teknologi yang cukup rumit seperti steam reforming, sedangkan produksi oksigen harus menggunakan teknologi yang sangat kompleks yakni teknologi kriogenik. Penelitian ini berupaya memberikan solusi yang sederhana dan mudah dioperasikan untuk memproduksi gas H2 maupun O2 melalui reaksi elektrolisis larutan KOH menggunakan metode elektroda unggun tetap yang tersusun atas stainless steel ball. Rancangan unggun tetap dengan berat unggun 300 gram didapatkan luas permukaan sebesar 362 cm2, tinggi unggun 3,05 cm, yang tersusun atas 286 stainless steel ball ukuran diameter 0,635 cm/ball. Terdapat tiga buah variasi yang dilakukan pada penelitian ini yaitu tegangan listrik (3, 3,5, 4, 4,5, dan 5 V), laju alir sirkulasi elektrolit (100, 200, 300, 400, 500 mL/menit), dan kadar KOH (1%, 2%, 3%, 4%, dan 5% W/W). Hasil percobaan menunjukkan kondisi optimum diperoleh pada tegangan 3 V, laju alir sirkulasi elektrolit 500 mL/menit, dan kadar KOH 3% didapatkan produktivitas gas hidrogen sebesar 0,813 mL/s dan oksigen sebesar 0,409 mL/s serta efisiensi energi sebesar 49,75%

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Hydrogen gas is a green fuel that is environmentally friendly because the combustion process does not produce carbon dioxide (CO2) gas. On the other hand, oxygen requirements for treating special patients must be available instantly. The availability of hydrogen gas must be produced with a complicated technology such as steam reforming, while the production of oxygen must use a very complex technology, namely cryogenic technology. This study seeks to provide a simple and easy-to-operate solution to produce H2 and O2 gas through the electrolysis reaction of KOH solution using a fixed bed electrode method composed of stainless steel ball. The fixed bed design with a bed weight of 300 grams obtained a surface area of 362 cm2, a bed height of 3,05 cm, which was composed of 286 stainless steel balls with a diameter of 0,635 cm/ball. There are three variations carried out in this study, namely the electric voltage (3, 3,5, 4, 4,5, and 5 V), the circulation rate of the electrolyte solution (100, 200, 300, 400, 500 mL/minute), and KOH content (1%, 2%, 3%, 4%, and 5% W/W). The experimental results showed that the optimum conditions were obtained at a voltage of 3 V, a circulation rate of 500 mL/minute of electrolyte solution, and a 3% KOH level. The productivity of hydrogen gas was 0,813 mL/s and oxygen was 0,409 mL/s and energy efficiency was 49,75%."

"Hidrogen merupakan salah satu bahan bakar yang diusulkan sebagai energi karena memiliki sifat ramah lingkungan serta memiliki kapasitas penyimpanan energi tinggi (143 MJ/kg). Hidrogen dapat diproduksi melalui proses elektrolisis sehingga lebih ramah lingkungan dibandingkan proses steam methane reforming (SMR). Pada dasarnya, elektrolisis larutan NaCl memiliki prinsip mengubah energi listrik menjadi energi kimia. Beberapa faktor yang mempengaruhi efisiensi energi dalam konversi ini adalah bahan dan geometri elektroda, konsentrasi larutan, pola alir larutan, serta elektron transfer pada permukaan. Untuk memastikan transfer elektron maksimal, tipe aliran yang digunakan adalah elektrolisis kontinyu. Dalam hal ini, larutan yang digunakan adalah larutan NaCl pada konsentrasi 1M dan 2M. Selain itu, terdapat variasi ukuran mesh, yakni 30; 40; 60; 80; dan 100, dengan variasi arus listrik pada 3A dan 5A. Bahan elektroda yang digunakan adalah lembaran Stainless Steel (SS316) yang digulung sehingga membentuk elektroda sirkular. Didapatkan hasil laju produksi gas hidrogen tertinggi pada 2 gulung mesh untuk konsentrasi 2M hingga 40mL/s dibandingkan dengan 1 gulung mesh yang hanya 35mL/s. Efisiensi energi tertinggi didapat pada mesh 60 (35,7%), disusul dengan mesh 80 (29,8%). Pada mesh 100 terdapat penurunan efisiensi (27,9%). Hal ini diakibatkan karena pembentukkan senyawa Fe yang mengendap pada permukaan aktif elektroda.

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Hydrogen is proposed as a fuel source due to its high energy storage capacity (143 MJ/kg).Although commonly produced through steam methane reforming, production through electrolysis is more evironmentally friendly. The electrolysis of NaCl solution has a principle of turning electrical into chemical energy in the form of hydrogen gas. Several factors that influence the efficiency energy of this conversion is the raw material, electrode geometry, solution concentration, solution flow pattern, and electron transfer on the surface. To ensure maximum surface reaction, the type of flow used is continuous electrolysis. Several variations made in this research include concentration of 1M and 2M, mesh sizes of 30; 40; 60; 80; and 100, and electric current variations at 3A and 5A. The electrodes utilized are made of Stainless Steel (SS316) wrapped to form a circular electrode. The results indicates that the flow rate of hydrogen is highest at 2 layers of mesh reaching up to 40mL/s compared to 1 layer of mesh at only 35mL/s. The highest energy efficiency is obtained at 60 mesh (35,7%), followed by mesh 80 (29,8%). At 100 mesh, there is a decline of energy efficiency (27,9%). This is due to the formation of Fe which deposits at the active surface of the electrode."

"Fabrikasi Carbon Nanotube CNT secara komersial terhalang oleh biaya produks meliputi: sumber karbon, katalis, dan energi. Stainless steel merupakan substrat potensial untuk fabrikasi CNT, kandungan Fe dan Ni menjadikan stainless steel berfungsi ganda sebagai substrat sekaligus katalis. Pada penelitian ini stainless steel di preparasi dengan HCl 37,8 dan oxidative heat treatment 850 oC selama 30 menit. Penelitian ini bertujuan mengidentifikasi pengaruh oxidative heat treatment pada stainless steel dalam pembentukan CNT. Identifikasi dilakukan menggunakan sumber karbon asetilena dan kamper. Substrat stainless steel 304 divariasikan atas foil, pelat, dan wiremesh. Hasil penelitian dengan asetilena selama 20 menit pada ketiga variasi menghasilkan carbon loss diatas 90. Hal ini disebabkan peningkatan persentase Cr menghambat pembentukan nano partikel katalis. Dengan bantuan ferrocene substrat foil, pelat, dan wiremesh menghasilkan CNT dengan massa 0,0573 gram; 0,0701 gram; dan 0,1246 gram disertai penurunan carbon loss mencapai 30. Penggunaan substrat stainless steel 316 dengan kandungan Cr lebih rendah dan tambahan waktu sintesis menjadi 60 menit menghasilkan massa 0,6325 gram dan carbon loss 2,76. Identifikasi dengan menggunakan kamper selama 60 menit menghasilkan peningkatan massa CNT pada stainless steel 304 foil 0,831 gram; pelat 1,856 gram; wiremesh 2,6305 gram dan 316 pelat 2,1075 gram .

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Commercial CNT fabrication is hindered by its production costs including carbon sources, catalysts, and energy. Stainless steel is potential for CNT fabrication as Fe and Ni contents function as substrate and catalyst. Stainless steel is prepared with HCl 37,8 and 850 oC oxidative heat treatment for 30 minutes. This study aims at identifying oxidative heat treatment effect on stainless steel in CNT formation performed using the carbon sources of acetylene and camphor. 304 stainless steel substrates are varied including foil, plate, and wiremesh. By using acetylene for 20 minutes results in carbon loss above 90 increasing the Cr inhibiting the formation of nano particles catalyst. The addition of ferrocene decrease the carbon loss up to 30 and CNT of 0,0573 gram 0,0701 gram and 0,1246 gram are formed in foil, plate, and wiremesh. The use of 316 stainless steel substrate with lower Cr content and additional time of synthesis to 60 minutes yield a mass of 0,6325 gram and carbon loss 2,76 . The 60 minutes identification using camphor results in CNT mass increase in the 304 stainless steel foil 0,831 gram plate 1,856 wiremesh 2,6305 gram and 316 plate 2,1075 gram."

"?Chemical engineers designing, operating and maintaining their ever-expanding industry during the second half of the 20th century relied heavily on stainless steels. Few, however, were familiar with or understood its history. This treatise satisfies that shortcoming in an interesting, readable manner. The ?Timeline? alone is a remarkable presentation.? Richard Leonard, retired, Hercules, Inc."

"Studi ini mempelajari tentang ketahanan korosi dari baja tahan karat duplex 2205 dan baja tahan karat feritik 410S terhadap konsentrasi larutan sodium klorida. Mekanisme korosi yang terjadi disebabkan oleh potensial breakdown Eb dan potensial proteksi Ep yang nilainya didapat selama pengujian polarisasi siklik. Variabel dari penelitian ini adalah konsentrasi dari larutan sodium klorida yang dipersiapkan pada konsentrasi 1 , 2 , 3,5 ,4 ,5 berat masa. Pengujian polarisasi siklik menghasilkan kurva untuk masing - masing material baja tahan karat pada setiap konsentrasi larutan NaCl dimana masing - masing kurva tersebut menunjukan nilai Eb dan Ep secara berurutan.Ketahanan korosi terbaik didapat pada konsentrasi 1 sodium klorida dan ketahanan korosi terburuk didapat pada larutan dengan konsentrasi 3,5 untuk kedua material baja tahan karat 2205 dan baja tahan karat 410S. Korosi sumuran terjadi pada baja tahan karat 410S namun tidak pada baja tahan karat 2205.

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Corrosion resistance of duplex stainless steels 2205 type and ferritic stainless steel 410S type were investigated due to the influence of the concentration of sodium chloride solution. The corrosion mechanism was caused by the breakdown potential Eb and protection potential Ep during the cyclic polarization testing. Aqueous sodium chloride solution with concentration of 1 , 2 , 3.5 , 4 , 5 w.t were prepared as the variable of the investigation. The cyclic polarization testing results the curves for both stainless steels in every concentration of NaCl solution which showed potential that indicate the onset of Eb and Ep respectively.The highest corrosion resistance was achieved in 1 sodium chloride solution and the lowest was in 3.5 sodium chloride solution for both 2205 ss and 410S ss. Pitting corrosion occurred in 410S SS but not in 2205 SS."

"Elektrolisis plasma menjadi metode sintesis green hydrogen dan hidrogen peroksida yang memisahkan air menjadi gas H2 dan O2 dengan plasma katodik pada tegangan di atas elektrolisis konvensional akibat rekombinasi radikal H• dan •OH. Laju erosi elektroda akibat suhu plasma yang tinggi menjadi keterbatasan pada proses ini sehingga Stainless Steel SS – 201 yang memiliki laju erosi lebih kecil dibandingkan tungsten (Lukkes, et al. 2006) diteliti efektivitasnya dari jumlah mmol produk, energi spesifik (Wr), dan laju erosi. Penelitian dilakukan dengan melakukan uji rancang bangun reaktor elektrolisis plasma dan karakterisasi arus tegangan untuk menentukan kondisi operasi menggunakan elektrolit NaOH 0,02 M dan Na2SO4 pada konduktivitas serupa, serta konsentrasi aditif metanol sebagai scavenger radikal •OH. Hasil penelitian menunjukkan bahwa SS – 201 memiliki erosi yang lebih kecil sebesar 0,07 gram dibandingkan tungsten sebesar 1,05 gram setelah 60 menit proses. Pembentukan lapisan oksida pasif SS – 201 menambah luas kontak elektroda dan menghasilkan gas H2 sebanyak 104,55 mmol dibandingkan tungsten sebanyak 94,95 mmol. Penelitian ini juga membandingkan pengaruh penggunaan NaOH dan Na2SO4 dengan konduktivitas serupa yang menunjukkan NaOH menghasilkan lebih banyak H2 dibandingkan Na2SO4 sebanyak 97,55 mol karena cenderung mengarah pada produksi hidrogen peroksida karena komposisi elektrolit yang mendorong pembentukan radikal •OH. Selain itu, pengaruh variasi metanol diuji yang menunjukkan bahwa penambahan aditif metanol tidak hanya berperan sebagai scavenger radikal •OH namun terdekomposisi akibat plasma menghasilkan gas hidrogen dan radikal H•.

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Plasma electrolysis is a green hydrogen and hydrogen peroxide synthesis method that separates water into H2 and O2 gases with cathodic plasma at a voltage above conventional electrolysis due to the recombination of H• and •OH radicals. The electrode erosion rate due to high plasma temperature is a limitation in this process so that Stainless Steel SS – 201 which has a lower erosion rate than tungsten (Lukkes, et al. 2006) was examined for its effectiveness from the number of mmol of product, specific energy (Wr), and rate of erosion. The research was carried out by conducting design tests for plasma electrolysis reactors and characterizing current voltages to determine operating conditions using electrolytes of 0.02 M NaOH and Na2SO4 with similar conductivity, as well as the concentration of methanol additive as an •OH radical scavenger.

The results showed that SS-201 had less erosion of 0.07 gram compared to 1.05 gram of tungsten after 60 minutes of process. The formation of the SS-201 passive oxide layer increased the contact area of the electrodes and produced 104.55 mmol of H2 gas compared to 94.95 mmol of tungsten. This study also compared the effect of using NaOH and Na2SO4 with similar conductivity which showed that NaOH produced more H2 than Na2SO4 of 97.55 mmol because it tends to produce of hydrogen peroxide due to the electrolyte composition which encourages the formation of •OH radicals. In addition, the effect of methanol variations was tested which showed that the addition of additive methanol did not only act as an •OH radical scavenger but decomposed due to plasma to produce hydrogen gas and H• radicals."

"ABSTRAKMetal Injection Moulding MIM merupakan suatu metode aplikasi dari Metalurgi Serbuk PM dan Plastic Injection Moulding yang sedang banyak dikembangkan untuk pembuatan komponen-komponen kecil yang presisi. Teknologi ini dikenal dengan kelebihan-kelebihannya seperti produktivitas tinggi, near-net-shape, permukaan akhir benda yang baik, dan kemampuan produk untuk diberikan perlakuan panas guna mencapai sifat yang diinginkan. Logam yang paling banyak diaplikasikan pada PM adalah stainless steel hasil fabrikasi dengan metode atomisasi gas yang menghasilkan serbuk dengan ukuran dan distribusi ukuran kecil, bentuk spherical, dan tingkat kemurnian serbuk yang tinggi dengan kandungan oksigen rendah

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ABSTRACTMetal Injection Molding MIM is an application of Powder Metallurgy PM and Plastic Injection Moulding which is currently being developed to produce small yet precise components. This technology is known for its advantages such as high productivity, near net shape, good surface finish, and great heat treatability to achieve desirable properties. Most applied metal using PM is stainless steel fabricated by gas atomization that produces powder with small size and size distribution, spherical shape, and high purity powder with low oxygen content "

"Limbah fenol dan logam Cr(VI) merupakan dua jenis limbah industri yang sering ditemukan sebagai kontaminan limbah cair yang berbahaya serta sulit untuk didegradasi. Melalui penelitian ini, fenol dan Cr(VI) didegradasi secara bersamaan menggunakan reaktor elektrolisis plasma yang dilengkapi dengan titanium sebagai plasma anoda oleh spesies reaktif seperti radikal •OH, radikal •H dan molekul H2O2. Untuk efisiensi energi, injeksi udara diterapkan ke zona elektrolisis plasma, yang berkontribusi pada pembentukan spesies radikal. Penelitian ini bertujuan untuk mengetahui pengaruh variasi laju aliran injeksi udara, daya dan tegangan yang berkorelasi dengan persentase degradasi fenol-Cr(VI) serta konsumsi energi spesifiknya. Hasil penelitian menunjukkan kondisi operasi maksimum elektrolisis plasma dicapai pada laju injeksi udara 0,2 LPM; daya 330 W; tegangan 600 V; konsentrasi elektrolit 0,02 M Na2SO4. Dalam waktu 30 menit, fenol terdegradasi sebanyak 54% dan Cr(VI) tereduksi seluruhnya dengan konsumsi energi spesifik sebesar 100.888 kJ/mmol. Efek penambahan injeksi udara kedalam zona plasma akan berdampak terhadap penambahan jenis spesi reaktif dan mengurangi konsumsi energi, sedangkan peningkatan tegangan operasi akan mempengaruhi rasio spesi reaktif yang dihasilkan, sementara efek terhadap peningkatan daya operasi akan menambah jumlah dari radikal •OH, radikal •H dan molekul H2O2. Temuan dalam penelitian ini akan sangat membantu untuk menghilangkan polutan organik dan anorganik secara bersamaan dalam air limbah yang kompleks.

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Phenols and Cr(VI) are hazardous organic and heavy metal wastes produced from various industrial processes such as textile, paint, and electroplating. Through this research, phenol and Cr(VI) were degraded simultaneously using the plasma electrolysis reactor equipped with titanium as anode plasma by reactive species such as •OH radicals, •H radicals and H2O2 molecules. For energy efficiency, air injection is applied into the plasma electrolysis zone, which contributes to the formation of radical species. This research aims to obtain the effect of variations in the flow rate of air injection volatge and electrical power correlated with the percentage of phenol-Cr(VI) degradation and their specific energy consumption. The results showed maximum operating conditions of plasma electrolysis is achieved on the air injection rate of 0.2 LPM; 600 V; 330 W; and the electrolyte solution 0.02 M Na2SO4. Phenol degraded to 54% and Cr(VI) was degraded to 100% with a specific energy of 100.888 kJ/mmol within 30 minutes. The effect of adding air injection into the plasma zone will have an impact on the addition of reactive species and reduce energy consumption, while the increase in operating voltage will affect the ratio of reactive species produced, and the effect on increasing operating power will increase the number of radicals •OH, •H and H2O2. The findings in this research would be helpful for removing organic and inorganic pollutants simultaneously in complex wastewater."

"[ABSTRAKPenggunaan baja tahan karat dua fasa austenitik-ferritik (Duplex) UNS32205 telah digunakan secara luas pada berbagai sektor perusahaan, khususnya industri Minyak dan Gas serta industri Petrokimia karena memiliki sifat mekanik dan ketahanan korosi yang sangat baik. Pada penelitian ini,yang diamati adalah pengaruh konsentrasi NaCl pada lingkungan kerja baja tahan karat ini, yang bertujuan mencari konsentrasi yang bersifat paling korosif, dan juga dilakukan pengamatan terhadap pengaruh perubahan Ferrite Content atau nilai rasio dari kedua fasa penyusun baja tahan karat UNS32205 yaitu Austenit dan Ferrit.Pada sampel awal yang diamati tanpa diberikan perlakuan panas apapun memiliki nilai rasio fasa 40% Austenit ? 60 Ferrit. Perubahan Ferrite Content atau perubahan rasio tersebut dilakukan dengan melakukan dua metode pemanasan sampel. Yaitu pemanasan menggunakan maffle furnace pada temperatur 11000C dan ditahan selama 20 menit, dengan hasil rasio 42% Austenit ? 58% Ferrit dan nilai ketahanan korosi paling rendah. Dan juga dilakukan pemanasan dengan cara mengambil sampel pada daerah HAZ dengan temperatur antara 4000C-12000C dan langsung quench, dengan hasil pengamatannya adalah memiliki ketahanan korosi paling tinggi karena memiliki rasio 50,3% Austenit ? 49,7% Ferrit.ABSTRACTThe use of Duplex Stainless Steel UNS32205 has been widely used in various sectors of the company, particularly the oil and Gas industry and the petrochemical industry because it has excellent mechanical properties and corrosion resistance. In this study, the effect of NaCl concentration was observed on the stainless steel working environment, which aims to find the most corrosive nature of concentrations, and also carried out observations on the influence of Ferrite Content or change the value of the ratio of the phase constituent of stainless steel UNS32205 i.e. Austenite and Ferrite. On the initial samples were observed without any heat treatment has given the value of the phase ratio 40% Austenite ? 60 Ferrite. Ferrite Content changes or changes the ratio by doing two sample heating method. I.e. the heating furnace temperature on maffle using 11000C and detained for 20 minutes, with a ratio of 42% Austenit ? 58% Ferrit and lowest corrosion resistance value. And also done warming up by taking samples at the HAZ with temperature between 4000C-12000C and direct quench, with the results of its observations is to have the highest corrosion resistance because it has a ratio of 50.3% Austenite ? 49.7% Ferrite., The use of Duplex Stainless Steel UNS32205 has been widely used in various sectors of the company, particularly the oil and Gas industry and the petrochemical industry because it has excellent mechanical properties and corrosion resistance. In this study, the effect of NaCl concentration was observed on the stainless steel working environment, which aims to find the most corrosive nature of concentrations, and also carried out observations on the influence of Ferrite Content or change the value of the ratio of the phase constituent of stainless steel UNS32205 i.e. Austenite and Ferrite.On the initial samples were observed without any heat treatment has given the value of the phase ratio 40% Austenite – 60 Ferrite. Ferrite Content changes or changes the ratio by doing two sample heating method. I.e. the heating furnace temperature on maffle using 11000C and detained for 20 minutes, with a ratio of 42% Austenit – 58% Ferrit and lowest corrosion resistance value. And also done warming up by taking samples at the HAZ with temperature between 4000C-12000C and direct quench, with the results of its observations is to have the highest corrosion resistance because it has a ratio of 50.3% Austenite – 49.7% Ferrite.]"