Nugroho, RiyantoHeri (2012) Karakteristik Mekanik Baja Karbon Rendah (St 42) yang Diberi Perlakuan Pack Carburizing dan Pengerasan Fasa Ganda. Magister thesis, Universitas Brawijaya.
Abstract
Titik berat penelitian untuk melihat sejauh mana perubahan sifat mekanik, dalam hal ini peningkatan kekuatan tarik dan kekerasan baja karbon rendah yang mendapat perlakuan panas Pack carburizing dan pengerasan Fasa Ganda /. Proses Pack carburizing menggunakan campuran arang kayu 80% dan Barium Carbonate sebagai aktifator 20%. Variasi Temperatur Pack carburizing 800 ○ C, 850 ○ C, 900 ○ C, dengan waktu penahanan 3 jam. Pemanasan kembali dengan maksud untuk pengerasan sekaligus pembentukan fasa ganda pada semua material yang mendapat perlakuan Pack carburizing, masing-masing 730 ○ C dan 760 ○ C dengan waktu penahanan /2 0 menit, kemudian didinginkan kejut dengan air temperatur kamar. Kekuatan tarik diuji dengan Universal testing machine, Kekerasan diuji dengan Micro vickers.Speciement uji tarik sesuai standart JIS Z2201 no 14A, speciement uji kekerasan dengan ukuran panjang 20mm dan Ø 16mm, speciement uji kekerasan dipotong 3-4 mm untuk diamati kekerasan dan struktur mikro permukaan potongan melitang bagian tepi dan tengah. Variasi temperatur Pack carburizing tanpa dilanjutkan pengerasan fasa ganda menunjukkan sedikit perubahan kekerasan dan kekuatan, dari hasil Foto struktur menunjukkan terjadinya difusi karbon yang semakin dalam dan semakin banyak seiring dengan kenaikan temperatur Pack carburizing. Sedangkan proses Pack carburizing yang dilanjutkan pengerasan fasa ganda menunjukkan terjadinya peningkatan kekuatan tarik, material jang mendapat pelakuan awal, kekuatan tarik 401,02 [N/mm2], m meningkat menjadi 599[N/mm2] pada perlakuan Pack carburizing 900 ○ C, dilanjutkan pengerasan fasa ganda 760 ○ C. Kekerasan maksimum sejauh 100 μm dari tepi sebesar 740,5 HV nilai ini dihasilkan dari perlakuan Pack carburizing 900 ○ C yang dilanjutkan pengerasan fasa ganda 760 ○ C. Jangkauan difusi karbon proses Pack carburizing yang mempengaruhi peningkatan kekerasan untuk temperatur 800 ○ C sejauh 700 μm, temperatur 850 ○ C sejauh 1200 μm, dan temperatur 900 ○ C sejauh 2400μm.
English Abstract
This reserch has been focused to explore modifiction of mechanical properties of modified microstructure of low carbon steel. Particular attention was addressed to observe increasing of tensile strength and hardness of low carbon steels which were heat treated via pack carburizing. Moreover, observation on increasing hardness caused by existing of dual phases also has been scrutinized. Pack carburizing processes were carried out in medium that consist of a mixture of wooden charcoal and Barium Carbonate (BaCo 3 ) with composition of 80%wt and 20%wt respectively. BaCo 3 has used as an activator. Pack carburizing processes performed at 800 ○ C, 850 ○ C, 900 ○ C for 3 hours holding time. A /2 0 minutes reheating processes at 730 ○ C and 760 ○ C followed by water cooling to all sample were purposed for hardening and formation of multiple phases. tensile strength was tested with a universal testing machine, where as hardness was tested using micro-Vickers testing machine. Tensile specimens were prepared in according to JIS Z2201 No. 14A, while for hardness testing were prepare by cutting Ø20mm and Ø 16mm specimens into 3mm to 4mm thick. Hardness testing was performed across surface of samples. Pack carburized sample showed a minor variation in hardness and strength. As shown in microstructure, increasing of carburization temperature demonstrated a fur r deeper diffusion. increasing of tensile strength from 401.02[N/mm2] to 599 [N/mm2] and maximum hardness of 740.5 HV at position of 100μm from edge of sample has been demonstrated by sample that was carburized at 900 ○ C and followed development of dual phases structure at 760 ○ C. In addition, maximum hardness position t 700μm, 1200μm and 2400μm from edges were been believed to have a direct relation with diffusion progress at 800 ○ C, 850 ○ C and 900 ○ C respectively.
| Item Type: | Thesis (Magister) |
|---|---|
| Identification Number: | TES/620.17/NUG/k/041200698 |
| Subjects: | 600 Technology (Applied sciences) > 620 Engineering and allied operations > 620.1 Engineering mechanics and materials |
| Divisions: | Program Pascasarjana > Magister Studi Ketahanan Nasional, Program Pascasarjana |
| Depositing User: | Endro Setyobudi |
| Date Deposited: | 14 Aug 2012 14:34 |
| Last Modified: | 14 Aug 2012 14:34 |
| URI: | http://repository.ub.ac.id/id/eprint/158600 |
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