Evaluasi Kerusakan Dan Remaining Life Assessment Tube Katalis Primary Reformer Di Pabrik Amonia

Maula, Fina Rachmatul (2026) Evaluasi Kerusakan Dan Remaining Life Assessment Tube Katalis Primary Reformer Di Pabrik Amonia. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Tube katalis merupakan komponen yang digunakan untuk menghasilkan hidrogen pada proses sintesis amonia. Komponen ini beroperasi pada temperatur dan tekanan tinggi sehingga rentan mengalami degradasi material selama masa operasi. Penelitian ini bertujuan mengidentifikasi karakteristik material dan mekanisme kerusakan tube katalis berbahan 25Cr-35Ni–Nb–Ti yang telah beroperasi selama sekitar 140.000 jam. Evaluasi dilakukan melalui pengujian komposisi kimia, X-Ray Diffraction (XRD), metalografi, Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS) dan kekerasan. Hasil pengujian komposisi kimia menunjukkan bahwa material masih memenuhi spesifikasi ASTM A297 dan data material Kubota untuk paduan KHR35CT. Pengukuran ketebalan menunjukkan penurunan ketebalan tube dari 15,2 mm menjadi 11,37 mm, lebih rendah dari batas aman sebesar 13,87 mm. Hasil XRD mengidentifikasi fasa austenit (γ) dan karbida Cr₂₃C₆. Hasil pengamatan metalografi menunjukkan transformasi karbida Cr₇C₃ menjadi Cr₂₃C₆ yang disertai penebalan karbida dan pembesaran butir austenit. Hasil SEM-EDS menunjukkan terbentuknya creep void berupa isolated cavities di sekitar partikel karbida pada batas butir sebagai indikasi kerusakan creep tahap awal. Hasil pengujian kekerasan menunjukkan tidak terdapat perbedaan yang signifikan dari standar. Mekanisme kerusakan tube katalis diawali oleh paparan temperatur tinggi dalam jangka panjang yang menyebabkan evolusi mikrostruktur. Kombinasi temperatur tinggi dan tegangan yang bekerja secara terus-menerus kemudian memicu deformasi creep yang ditandai dengan grain boundary sliding dan pembentukan creep void pada batas butir. Akumulasi kerusakan yang terjadi selama operasi menunjukkan bahwa mekanisme creep merupakan penyebab utama degradasi material pada tube katalis. Hasil remaining life assessment menunjukkan bahwa material memiliki estimasi umur sisa sebesar 6,31 tahun, dengan nilai yang bersifat relatif mengikuti kondisi operasional.
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Catalyst tubes are components used to produce hydrogen in the ammonia synthesis process. These components operate at high temperatures and pressures, making them susceptible to
material degradation during operation. This study aims to identify the material characteristics and failure mechanisms of catalyst tubes made of 25Cr–35Ni–Nb–Ti that have been in
operation for approximately 140,000 hours. The evaluation was carried out through chemical composition analysis, X-ray diffraction (XRD), metallography, scanning electron microscopy energy dispersive spectroscopy (SEM–EDS) and hardness testing. The results of the chemical composition analysis showed that the material still met the ASTM A297 specifications and Kubota’s material data for the KHR35CT alloy. Thickness measurements indicated a reduction in tube thickness from 15.2 mm to 11.37 mm, which is below the safety limit of 13.87 mm. The XRD results identified the austenite (γ) phase and Cr₂₃C₆ carbides. Metallographic observations revealed the transformation of Cr₇C₃ carbides into Cr₂₃C₆, accompanied by carbide thickening and austenite grain coarsening. SEM-EDS results showed the formation of creep voids in the form of isolated cavities around carbide particles at grain boundaries, indicating early-stage
creep damage. Hardness test results showed no significant deviation from the standard. The failure mechanism of the catalyst tube was initiated by prolonged exposure to high temperatures, leading to microstructural evolution. The combination of high temperature and continuous
stress subsequently triggers creep deformation, characterised by grain boundary sliding and the formation of creep voids at the grain boundaries. The accumulation of damage occurring during operation indicates that the creep mechanism is the primary cause of material degradation in the catalyst tubes. The results of the remaining life assessment indicate that the material has an estimated remaining life of 6.31 years, with this value being relative to the operational conditions.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	Creep, KHR35CT, Remaining Life Assessment, Tube Katalis, Creep, KHR35CT, Remaining Life Assessment, Catalyst Tube
Subjects:	T Technology > TA Engineering (General). Civil engineering (General) > TA169 Reliability (Engineering) T Technology > TA Engineering (General). Civil engineering (General) > TA169.5 Failure analysis T Technology > TS Manufactures > TS320 Steel--Metallurgy.
Divisions:	Faculty of Industrial Technology and Systems Engineering (INDSYS) > Material & Metallurgical Engineering > 28201-(S1) Undergraduate Thesis
Depositing User:	Fina Rachmatul Maula
Date Deposited:	21 Jul 2026 07:16
Last Modified:	21 Jul 2026 07:16
URI:	http://repository.its.ac.id/id/eprint/136094

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