Hasil Pencarian  ::  Simpan CSV :: Kembali

"Penelitian ini bertujuan untuk mengetahui pengaruh kandungan nikel dalam elektroda terhadap sifat mekanis dan mikrostruktur pengelasan baja pelat SM570TMC dan AH36. Pengelasan material tersebut menggunakan metode Flux Cored Arc Welding (FCAW) dengan kawat las yang memiliki kandungan nikel 0%, 1%, dan 1,5%. Hasil dari pengelasan diteliti dengan pengujian tak rusak (MPT, UT) dan rusak (Hardness Vickers, impact charpy, pengamatan mikrografi (makro, mikro, SEM, EDS, OES)). Pengujian dilakukan pada area base metal (BM), Heat Affected Zone (HAZ) dan Weld Metal (WM). Pengujian impact charpy dilakukan pada temperatur 25⁰C, 0⁰C, dan -20⁰C. Pengujian NDT tidak mempengaruhi kualitas lasan. Hasil pengujian kekerasan pada penambahan 1% nikel material AH36 maksimum sebesar 190 HV dan minimum 163 HV sedangkan untuk material SM570TMC maksimum sebesar 172 HV dan minimum 154 HV. Material AH36 mempunyai nilai ketangguhan impak pada temperatur 0⁰C sebesar 280 J dan pada temperatur-20⁰C sebesar 200 J diarea HAZ. Material SM570TMC nilai ketangguhan impak sebesar 385 J pada temperatur 0⁰C dan 276 J pada temperatur -20⁰C diarea HAZ. Dengan penambahan 1% nikel menunjukkan dalam pengamatan mikro menghasilkan butiran yang lebih halus bila dibandingkan penambahan nikel 0 dan 1,5% sehingga mampu meningkatkan nilai ketangguhannya pada material AH36 dan SM570TMC terutama pada temperatur 0⁰Cdan -20⁰C.

---

This study aims to determine the effect of nickel content in electrodes on the mechanical and microstructure properties of welding steel plates SM570TMC and AH36. Welding of the material uses the method of Flux Cored Arc Welding (FCAW) with welding wire which has a nickel content of 0%, 1%, and 1.5%. The results of welding were examined by non-destructive testing (MPT, UT) and damaged (Vickers Hardness, charpy impact, micrographic observations (macro, micro, SEM, EDS, OES)). Tests were carried out on the base metal area (BM), Heat Affected Zone (HAZ) and Weld Metal (WM). Charpy impact testing is carried out at temperatures of 250C, 00C, and -200C. NDT testing does not affect weld quality. The hardness test results on the addition of 1% nickel AH36 material to a maximum of 190 HV and a minimum of 163 HV while the SM570TMC material is a maximum of 172 HV and a minimum of 154 HV. AH36 material has an impact toughness value at a temperature of 0⁰C of 280 J and at a temperature of -20⁰C of 200 J at HAZ area. Material of SM570TMC impact resistance value was 385 J at temperatures of 0⁰C and 276 J at -20⁰C at HAZ. With the addition of 1% nickel, the micro-observation produced finer grains when compared to the addition of 0 and 1.5% nickel so as to increase the toughness value of AH36 and SM570TMC materials, especially at temperatures of 0⁰C and -20⁰C."

"The effect of rice husk ash produced at different grinding times on the engineering properties of concrete was studied. Eight rice husk ashes representing different grinding times were used in this investigation. Rice husk ash (RHA) was used to partially replace Port land cement Type I at 15% by weight of cementitious material. The compressive strength of concrete was designed to achieve grade 40 N/mm2 at 28 days. A superplasticizer was added to all mixes to provideworkability in the range of 110-120 mm. However, the water to cement ratio (w/c) of the concrete was maintained at 0.49. Based on the results, the morphology of the rice husk ashes was changed by grinding. Optimum grinding time appeared to be approximately 90 minutes, during which time the compressive strength increased significantly. Generally, incorporation of RHA at various grinding times can dramatically decrease or increase the engineering properties of concrete. "

"Engineering design calculations for tank bottom sections, including direct current requirements and voltage calculations, followed by additional structures, such as electrical grounding systems, have already been successfully implemented and controlled in field conditions. Furthermore, the effect of soil resistivity in layers, oxygen content and the pH value of the soil against the disproportionate IR-Drop voltage, including its effect on potential distribution, have been already successfully observed. Other influences, such as the depth and location of the anode groundbed determination along with the establishment of impressed current cathodic protection related to the main tools and equipment, such as external corrosion control methods, have been defined as the most effective ways in order to control potential distribution against the additional structures. Persuant to the verification results from the site located at Marangkayu, East Borneo, it has been determined that high soil resistivity could cause error readings in accordance with the accumulation results of the true readings and the IR-Drop voltage, since under real conditions, the tank structure would have received less current flow from an anode compared to a lower result. Naturally, a low pH value from the soil would decrease soil resistivity and enhance potential distribution from the anodes to the tank structures. The results show that the cathodic protection required 10 additional anodes, (each one is of a tubular mixed metal oxide) with a DC supply at minimum amperage of 154 Amps and a minimum voltage supply of 32 Volts. During the research, it was identified that high soil resistivity above 3000 ohm-cm would cause error readings. Naturally, acidic soil is in the region of pH 5-7 value, which would decrease soil resistivity and enhance the potential distribution from the anode to the tank structure."