SUKENDAR, SUKENDAR (2026) PENGARUH MEDIA QUENCHING SILICON OIL, CASHEW NUT SHELL LIQUID, CRUDE PALM OIL, DAN KOMBINASINYA DENGAN Al2O3 TERHADAP STRUKTUR MIKRO DAN SIFAT BAJA. S2 thesis, Universitas Mercu Buana Jakarta.
|
Text (HAL COVER)
Cover.pdf Download (3MB) | Preview |
|
![[img]](https://repository.mercubuana.ac.id/style/images/fileicons/text.png) |
Text (BAB I)
BAB 1.pdf Restricted to Registered users only Download (588kB) |
|
|
Text (BAB II)
BAB 2.pdf Restricted to Registered users only Download (1MB) |
|
|
Text (BAB III)
BAB 3.pdf Restricted to Registered users only Download (915kB) |
|
|
Text (BAB IV)
BAB 4.pdf Restricted to Registered users only Download (1MB) |
|
|
Text (BAB V)
BAB 5.pdf Restricted to Registered users only Download (809kB) |
|
|
Text (DAFTAR PUSTAKA)
Daftar Pustaka.pdf Restricted to Registered users only Download (348kB) |
|
|
Text (LAMPIRAN)
Lampiran.pdf Restricted to Registered users only Download (789kB) |
Abstract
Steel is widely used in engineering applications due to its low cost and highly customizable mechanical properties. S45C steel is one of the most commonly used grades because it provides a good balance between strength and ductility. However, in applications subjected to high dynamic loads, such as shafts, enhanced mechanical performance becomes essential. One of the most effective methods to improve mechanical properties is the quenching heat-treatment process. Conventional quenching media such as water often cause thermal cracking and distortion, while mineral oils present risks of flammability and are less environmentally friendly. This study explores Silicon Oil, Crude Palm Oil (CPO), and Cashew Nut Shell Liquid (CNSL), along with their modifications through the addition of 0.015 wt% Al2O3 nanoparticles, as alternative quenching media. The specimens were austenitized at 850°C for 120 minutes, quenched, and subsequently tempered at 500°C for 100 minutes. The results show that specimens quenched in CPO with 0.015 wt% Al2O3 exhibited the best performance, with hardness increasing from 31.8 HRC to 49.55 HRC after tempering. The ultimate tensile strength increased from ~674 MPa to ~783 MPa, while the yield strength increased from ~408 MPa to ~517 MPa, with an elongation of 18.7%, demonstrating an excellent balance between strength and ductility. Microstructural analysis confirmed the formation of fine tempered martensite with homogeneous carbide precipitation. Additionally, there was an increase in carbon content from 0.43 to 0.463 wt%, as well as an increase in micro-lattice strain (0.45 × 10⁻³) with a crystallite size of approximately 68 nm. The three nanoparticle-modified quenching media exhibit strong potential as sustainable alternative quenching media. Keywords: S45C Steel, Quenching Heat Treatment, Alternative Quenching Media, Mechanical Properties, Steel Microstructure. Baja menjadi material yang banyak digunakan dalam aplikasi teknik karena biayanya rendah dan sifat mekaniknya dapat direkayasa. Baja S45C sering digunakan untuk berbagai aplikasi teknik, karena memiliki keseimbangan kekuatan dan keuletan yang baik. Namun, pada aplikasi dengan beban dinamis tinggi seperti poros dan lain-lain peningkatan performa mekanik menjadi suatu kebutuhan. Salah satu metode untuk meningkatkan sifat mekanik adalah perlakuan panas quenching. Penggunaan media quenching konvensional seperti air sering menyebabkan retak thermal dan distorsi, sementara penggunaan minyak mineral beresiko mudah terbakar dan kurang ramah lingkungan. Penelitian ini mengeksplorasi Silicon Oil, Crude Palm Oil (CPO), dan Cashew Nut Shell Liquid (CNSL), serta modifikasinya dengan penambahan 0,015 wt% nanopartikel Al2O3, sebagai media quenching alternative. Specimen di austenitisasi pada suhu 850°C selama 120 menit, kemudian di quenching, lalu di tempering pada suhu 500°C selama 100 menit. Hasil menunjukkan bahwa sampel yang di quenching menggunakan CPO ditambah 0,015 wt% Al2O3 memberikan performa terbaik, dengan peningkatan kekerasan dari 31,8 HRC menjadi 49,35 HRC setelah tempering. Ultimate tensile strength meningkat dari ~674 MPa menjadi ~783 MPa, sedangkan yield strength meningkat dari ~408 MPa menjadi ~517 MPa, dengan elongasi 18,7%, mencerminkan keseimbangan kekuatan dan keuletan. Analisis mikrostruktur mengonfirmasi terbentuknya martensit temper halus dengan presipitasi karbida homogen. Selain itu juga ada peningkatan kadar karbon dari 0,43 menjadi 0,463 wt%, dan peningkatan regangan kisi mikro (0,45 × 10⁻³) dengan ukuran kristalit (~68 nm). Secara keseluruhan, tiga media quenching yang dimodifikasi nanopartikel Al2O3 berpotensi menjadi media quenching alternative berkelanjutan. Kata Kunci: Baja S45C, Perlakuan panas quenching, Media quenching alternative, Sifat mekanik baja, Microstruktur Baja.
Actions (login required)
 |
View Item |
