66 research outputs found
Investigasi Pengaruh Inhibitor Korosi Molibdat Terhadap Laju Korosi Pipa Injeksi Sistem Waterflood (Baja Karbon Api 5l GR B) Dengan Media Air Formasi Sumur Minyak Bumi Jenis Sumatra Light
Get PDFPenyebab terbesar kebocoran sistem perpipaan di industri minyak dan gas bumi adalah karena korosi, hal ini juga tidak terkecuali pada sistem perpipaan injeksi waterflood. Salah satu langkah untuk mencegah korosi adalah dengan cara menambahkan inhibitor korosi ke dalam pipa. Penelitian ini menginvestigasi pengaruh inhibitor molibdat dengan variasi konsentrasi 0 dan 1% terhadap laju korosi pipa API 5L Grade B di lingkungan air formasi. Hasil penelitian menunjukkan laju korosi material di lingkungan air formasi sumur produksi tanpa adanya inhibitor sama sekali adalah 107,7769 mpy atau 2,7375 mm/year. Dari hasil penelitian didapat bahwa laju korosi material pada lingkungan air formasi dengan konsentrasi molibdat 1% adalah sebesar 64,1718 mpy atau 1,6300 mm/year. Penambahan inhibitor molibdat berhasil menurunkan laju korosi pipa dengan efektifitas penghambatan korosi sekitar 40%. Dari data tersebut maka dapat disimpulkan bahwa penambahan inhibitor membuat baja karbon rendah lebih tahan terhadap korosi
PENGARUH INTENSITAS SHOT PEENING DENGAN BALL SIZE 0,28” TERHADAP TINGKAT KEKERASAN PERMUKAAN MATERIAL PESAWAT TERBANG AA 7050-T7651
No full textPenelitian ini dilakukan bertujuan untuk mempelajari dan membuktikan pengaruh intensitas shot peening terhadap peningkatan kekerasan permukaan pada material pesawat terbang AA 7050-T7651.Spesimen dikelompokkan dalam dua kategori BMSP8 (Base Metal Shot Peened dengan intensitas 0,008Almen), BSMP10 (Base Metal Shot Peened dengan intensitas 0,010Almen). Proses perlakuan Shot Peening menggunakan bahan steel dengan Ball Size 0,028 inch dengan intensitas 0,008 Almen dan 0,010 Almen.Hasil pengujian tingkat kekerasan spesimen BMSP8 menunjukkan hasil HVN 160 kg/mm2 sedangkan spesimen BMSP10 menunjukkan tingkat kekerasan HVN 171 kg/mm2 Dengan demikian terlihat bahwa peningkatan intensitas shot peening dari 0,008 Almen menjadi 0,010 Almen terbukti meningkatkan kekerasan pada permukaan material.Kata kunci: Shot peening, AL 7050, kekerasan, vicker
PENGARUH SHOT PEENING PADA MATERIAL PESAWAT TERBANG AL 7050-T7651TERHADAP LAJU PERAMBATAN RETAK FATIK
Get PDFKonstruksi pesawat terbang umumnya akan mengalami beban dinamis berupa tegangan tarik, tekan, bending, atau kombinasinya yang mengakibatkan kegagalan fatik. Selain itu, pesawat terbang juga beroperasi pada wilayah udara dengan berbagai kondisi lingkungan seperti keasaman, kebasaan, garam, kelembaban dan temperatur yang bervariasi, yang akan mempercepat laju korosi. Perlakuan permukaan shot peening dan anodisasi paling banyak diaplikasikan untuk meningkatkan ketahanan fatik dan korosi pada konstruksi pesawat terbang. Penelitian ini bertujuan untuk mempelajari dan membuktikan pengaruh shot peening terhadap laju perambatan retak fatik pada material Al 7050-T7651.Spesimen dibentuk sesuai dengan standar ASTM E647, dikelompokkan dalam dua kategori as received material-tanpa perlakuan (AR) dan base metal shot peened (BMSP). Proses perlakuan shot peening (dengan intensitas Almen 0,006 A, diameter shot 0,017 inch) dilakukan di area surface treatment PT. Dirgantara Indonesia. Selanjutnya pengujian perambatan retak fatik dilakukan dengan mesin Servopulser di Lab. Bahan Teknik Jurusan Teknik Mesin UGM, dengan beban sekitar 11% dari tegangan tarik maksimum (spesimen standar ASTM E8M) yang dihubungkan dengan analisis beban kombinasi, dengan stress ratio R=0,1. Data hasil uji tersebut diolah menggunakan metode incremental polynomial untuk mendapatkan hubungan da/dN - ΔK. Hasil uji perambatan retak fatik pada spesimen AR menghasilkan angka konstanta Paris A=1,288×10-9dan n=2,02 dan BMSP dengan A=1,286×10-9 dan n=2,01. Dengan demikian perlakuan shot peening terbukti menurunkan lajuperambatan retak fatik meskipun tidak terlalu signifikan
Effects of rotational speed on the mechanical properties and performance of AA6061-T6 aluminium alloy in similar rotary friction welding
No full textSimilar rotary friction welding with AA6061-T6 rod material was carried out at four variations of rotational speed in order to study the effect of rotational speed on the joint properties. The increase in rotational speed produces higher hardness value in DRZ area, i.e. the lowest microhardness value in the DRZ area was 129 VHN at 380 rpm and increased to 192 VHN at 1700 rpm due to a grain refinement process that increased the hardness as the Hall�Petch equation. Otherwise, in the HAZ and TMAZ area, the microhardness profile has a decreasing trend due to the welding rotation increases. All welded joints have a lower strength than the base metal, about 68% for tensile and 83% for fatigue. The observations on the fracture surface of tensile and fatigue test showed that the fracture's area occurs in the same region where the lowest microhardness and roughness grain sizes occur
Peningkatan Ketahanan Korosi Pada Material Biomedik Plat Penyambung Tulang SS 304 Dengan Gabungan Metode Shot peening dan Electroplating Ni-Cr
Get PDFStainless steel (SS) 304 is widely used as biomedical materials because of its lower cost and its availability. However its corrosion resistance is lower than that of the SS 316L. The purpose of this study is to determine the influence of the combination surface treatment i.e. shot peening treatment and electroplating Ni-Cr on the corrosion resistance in simulated body fluid (SBF) of SS 304 material. The shot peening treatments were carried out using a variable period of 5, 15 and 30 minutes. Diameter steel balls of 0.6 mm with a hardness of 40-50 HRc, was applied. Pressure compressor was maintained in the range of 6 -7 kg / cm2 with nozzle diameter and the distance between nozzle and the specimen of 5 mm and 10 cm respectively. After shot peening process, the specimens were nickel-electroplated using a voltage of 2 V at current of 0.03 A with the distance between the electrode of 4 cm for 15 minutes. After nickel-electroplated process the specimens were chrome-electroplated using a voltage of 4.5 V at current 0.3 A with the distance between the electrode of 15 cm for 5 minutes. The specimen was then tested its corrosion rate in the test medium SBF using Galvanostat M 273 in the range of -20 mV s / d 20 mV. The corrosion test results show that SS 316L and SS 304 without treatment have corrosion rate respectively 1.212 X 10-3 mm / year and 4,003 x 10-3 mm / year. Which means that corrosion rate of SS 304 is 333% higher than SS 316L. The corrosion rate after treatment shot peening 5, 15 and 30 minutes followed by Ni-Cr electroplating is respectively 2.121 x 10-3 mm / year, 0.554 x 10-3 mm / year and 0 mm / year (not detected by the measurement instrument)
The effects of welding current and purging gas on mechanical properties and microstructure of tungsten inert gas welded aluminum alloy 5083 H116
No full textAluminum alloy 5083 H116 has an exceptional performance in extreme environments, moderately high strength, outstanding corrosion resistance in salt water and high impact strength at cryogenic temperature. In the present study, Aluminum alloy AA 5083 H116 plates were joined by tungsten inert gas (TIG) process by single and double sided welding. Welding current used was 53 A and 80 A with the addition of purging gas during welding process. The effects on micro structure and mechanical properties like surface hardness and tensile strength of the welded region were studied. The results have shown that optimum current out of the two weld current used is 53 A. Better microstructures, tensile and hardness were found in the welded joint for the weld current 53 A where the tensile obtained in the softened zone was approximately 87% than that of the base metal (BM). With increasing of TIG current, the width of PMZ increased. In addition, the doubled sided welding sequence also produced broader PMZ area
PENGARUH HEAT TREATMENT T6 DENGAN VARIASI SUHU AGING TERHADAP KARAKTERISTIK SIFAT FISIS DAN MEKANIS VELG PADUAN ALUMUNIUM A356 PRODUK OEM TERNAMA
No full textVelg is vehicle components that will undergo static load and dynamic
loads during use. The load can cause the velg decreased mechanical properties,
even can cause failure. This research aims to determine whether the effect of heat
treatment T6 and artificial aging on the aluminum A356 towards physical
properties and the mechanical of velg.
The material used in this research is the A356 aluminum alloy motorcycle
velg. Test specimens were made based on JIS Z 2201 standard for tensile test and
JIS Z 2202 for impact toughness test. This research uses five types of specimens
that 1 type of specimen without undergoing heat treatment T6,1 type of specimen
being subjected to T6 heat alone, and 3 types of specimens T6 heat treatment and
artificial aging. Variations T6 heat treatment is conducted at a temperature of 5400
C heating specimen with hold time for 4 hours and then continued with aging at
temperatures 1000 C, 1500 C, and 2000 C with a hold time of 3 hours.
The test results showed that the alloy composition is made of aluminum
alloy A356 with main composition of Al, Si, and Mg. After testing, the highest
impact toughness possessed by the specimen with T6 heat treatment with the
artificial aging temperature of 1000 C in the amount of 0.068 joule/mm2, while the
tensile strength is owned by the largest non Heat Treatment specimens with
tensile strength of 248.8 MPa. Porosity in the whole specimen is considered equal
to porosity testing is only done on one specimen only
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