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All Journal Manufaktur: Publikasi Sub Rumpun Ilmu Keteknikan Industri Scientific Contributions Oil and Gas
Lestari, Venty
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Aerospace Engineering Automotive Engineering Chemical Engineering, Chemistry & Bioengineering Civil Engineering, Building, Construction & Architecture Control & Systems Engineering Energy

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Karakterisasi Struktur Mikro dan Sifat Mekanik Paduan Al-Mg-Si Hasil Squeeze Casting Setelah Perlakuan Homogenisasi Lestari, Venty
Manufaktur: Publikasi Sub Rumpun Ilmu Keteknikan Industri Vol. 3 No. 3 (2025): Manufaktur : Publikasi Sub Rumpun Ilmu Keteknikan Industri
Publisher : Asosiasi Riset Ilmu Teknik Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.61132/manufaktur.v3i3.1192

Abstract

Al–Mg–Si aluminum alloys are widely utilized in engineering applications due to their low density, excellent corrosion resistance, and mechanical properties that can be modified through heat treatment. This study investigates the effect of homogenization on the microstructure and hardness of Al–Mg–Si alloys produced by the squeeze casting process. The experimental procedure involved alloy melting, squeeze casting at 76 MPa using preheated metal molds, followed by homogenization at 400 °C for 4 hours. Microstructural characterization was performed using optical microscopy to examine the dendritic morphology and measure the secondary dendrite arm spacing (SDAS). Mechanical properties were evaluated through Vickers microhardness and Rockwell macrohardness testing. The results show that homogenization increases the SDAS from 32.59 μm to 36.88 μm and decreases the volume fraction of interdendritic phases from 15.51% to 13.57%. Furthermore, microhardness decreased from 50.22 VHN to 38.58 VHN, while macrohardness decreased from 54.60 HRE to 46.64 HRE. These reductions are attributed to the partial dissolution of Mg₂Si precipitates into the aluminum matrix during homogenization. Overall, this research provides valuable insight into the optimization of initial heat treatment parameters for Al–Mg–Si alloys produced by squeeze casting. The findings highlight the role of homogenization in improving microstructural uniformity and preparing the alloy for subsequent deformation processes such as cold rolling and extrusion, particularly for structural components used in mining and heavy transportation industries.
Impact Assessment of Wax Gelation Fluid Pressure and Temperature: Designing Long-Term Preventive Solutions Hasan, Meutia Fitri; Lestari, Venty; Budiman, Hendra; Setiawan, Aldo; Pamungkas, Mohd Wirawan Putra
Scientific Contributions Oil and Gas Vol 48 No 4 (2025)
Publisher : Testing Center for Oil and Gas LEMIGAS

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29017/scog.v48i4.1932

Abstract

Paraffinic precipitation presents a pervasive flow challenge, specifically impacting this light crude oil (API 34.85 °) system, particularly within a pipeline (length 1153 m) operating in cold environments. This study first rigorously assessed the critical impact of flow parameters, confirming the fluid’s thermal profile drops below the pour point (31.67 oC) at a crucial distance of 439.24 m from the wellhead, initiating severe wax gelation. Flow analysis further confirms a detrimental laminar flow regime (NRe = 1262), which, coupled with a significant total pressure drop of 0.155 psia/100 ft along the pipeline, exacerbates the tendency for solidified paraffins to accumulate due to insufficient shear stress. To address this, the research successfully validated a cost-effective, long-term preventative solution: a locally fabricated sand heater with an energy capacity of 175,000 kcal/h. Empirical field testing confirmed the intervention provides a substantial net thermal elevation of 8.5 oC. Subsequent thermal modeling for long-term operational reliability identified the optimal sand-heater placement distance to be within 300 m of the wellhead. This strategic placement ensures the fluid temperature consistently remains safely above the pour point, effectively mitigating the risk of premature wax gelation and guaranteeing uninterrupted system integrity and sustained hydrocarbon production.
Co-Authors Hasan, Meutia Fitri Hendra Budiman Pamungkas, Mohd Wirawan Putra Setiawan, Aldo