Riyanta, Bambang (2017) Prinsip Keseimbangan Energi pada Prediksi Ketangguhan Retak Kritis (KIC) dan Fracture Resistance Kritis (JIC) Baja AISI 304 di Daerah Sambungan Las. Doctor thesis, Universitas Brawijaya.
Abstract
Pemanfaatan Stainless Steel untuk berbagai keperluan saat ini semakin meningkat. Pengelasan Stainless Steel berpotensi menghadapi masalah retak yang dianggap sebagai masalah paling serius dibanding berbagai cacat fisik lainnya. Retakan pada komponen struktur, bisa mengakibatkan kegagalan pada tingkat tegangan yang lebih rendah dibanding tegangan maksimal yang mampu diterima material. Banyak kegagalan terjadi akibat retak, meski tegangan luluh belum tercapai. Energi pengelasan mempengaruhi struktur mikro dan ketangguhan retak material. Penelitian ini dilakukan untuk memprediksi ketangguhan retak kritis (KIC) dan fracture resistance kritis (JIC) Baja AISI 304 pada zona pengelasan dengan pendekatan keseimbangan energi. Rumus keseimbangan energi di setiap zona diperoleh dengan memperkirakan suplai energi pengelasan dan konsumsi energi dalam beberapa proses yang terjadi di setiap zona pengelasan seperti: remelting/solidification, pertumbuhan butir, rekristalisasi, sensitisasi dan pembangkitan tegangan sisa. Neraca energi digunakan untuk mengevaluasi profil fracture resistance pada setiap zona pengelasan : Fusion Zone, High Temperature Heat Affected Zone, Low Temperature Heat Affected Zone dan Unaffected Base Metal. Berdasarkan pendekatan keseimbangan energi, penelitian ini mengembangkan model baru untuk memperkirakan ketangguhan retak kritis (KIC) dan fracture resistance kritis (JIC) Baja AISI 304 pada masing-masing zona pengelasan. Pengujian laboratorium fracture resistance merujuk pada standar pengujian ASTM E 1820 pada pengelasan AISI 304 dilakukan pada penelitian ini. Percobaan dilakukan menggunakan mesin hydraulic servo pulsher pada compact tension specimen tunggal . Dilakukan pencatatan Load (P) vs Displacement (v) untuk perumusan kurva J-R. Mekanisme retak dan komposisi presipitat dianalisis dengan menggunakan mikroskop optik (OM), scanning electrone microscope (SEM) dan Energy Dispersive X-Ray Spectroscopy (EDS). Hasil penelitian menunjukkan harga fracture resistance kritis (JIC) yang dihitung dengan model keseimbangan energi memiliki kesesuaian yang baik dengan nilai fracture resistance kritis (JIC) yang diperoleh pada tampilan grafik kurva J-R hasil pengujian laboratorium. Hasil penelitian ini akan menjadi rujukan penting dalam pemanfaatan AISI 304 yang melibatkan proses pengelasan AISI 304.
English Abstract
Stainless Steel Utilization for various purposes nowadays is increasing. Stainless Steel welding potentially faces cracks problems which are considered to be the most serious problem than other variety of physical defects. When there are some cracks in structural component, it could fail at a lower stress level than the ultimate strength of the material. Many failures have occurred as a result of fracture, even though the yield stress is not reached. Welding energy affecting microstructures and fracture toughness of the material. This study was conducted to predict critical fracture toughness (KIC) and critical fracture resistance (JIC) of AISI 304 Steel on the welding zones by energy balance approach. The energy balance formula in each zone is obtained by estimating welding energy supplay and energy consumption in several processes in each zone such as : remelting / solidification, grain growth, recrystallization, sensitization and residual stress generation. The energy balance was used to evaluate the fracture resistance profile at each welding zone : Fusion zone, High Temperature Heat Affected Zone, Low Temperatur Heat Affected Zone and Unaffected Base Metal zone. Base on energy balance approach, this present research develops a new model to estimate post welding AISI 304 critical fracture toughness (KIC) and critical fracture resistance (JIC) in each welding zone. Laboratory experimental testing of AISI 304 welding fracture resistance were carried out in this study. Single Compact Tension Specimen experiments base on ASTM E 1820 were held to record Load (P) vs Displacement (v) in order to construct J-R curve as a fracture resistance profile graphical display. Fracture mechanism and precipitates composition were analyzed using optical microscope (OM), scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). The study result showed that the calculated JIC by the model has a good agreement with JIC values which are obtained on the J-R curve graphical display. This investigation will provide an important reference to engineering practice and evaluation. of AISI 304 welding.
Other obstract
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| Item Type: | Thesis (Doctor) |
|---|---|
| Identification Number: | DIS/691.7/RIY/p/2017/061802417 |
| Uncontrolled Keywords: | STAINLESS STEEL, STAINLESS STEEL—WELDING, FRACTURES |
| Subjects: | 600 Technology (Applied sciences) > 691 Building materials > 691.7 Iron and steel (ferrous metals) |
| Divisions: | S2/S3 > Doktor Teknik Mesin, Fakultas Teknik |
| Depositing User: | Budi Wahyono Wahyono |
| Date Deposited: | 13 Aug 2019 07:04 |
| Last Modified: | 22 Oct 2021 06:14 |
| URI: | http://repository.ub.ac.id/id/eprint/171322 |
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