Nitridasi Baja Karbon Medium dengan teknik Plasma Fokus

Abstract

Telah dilakukan nitridksi terhadap baja karbon medium, dengan tujuan untuk meningkatkan kekerasan permukaamiya Sampel yang digunakan mempunyai dimensi : panjang 2,8 cm, lebar. 1 cm, dan tebal 11,5 mm. Nitridasi dilakukan dengan menggunakan teknik plasma fokus, dalam berbagai variasi jumlah penembakan dan jarak antara sampel dengan elektroda. Sampel yang telah dinitridasi, kekerasannya diuji dengan menggunakan Micro Hardness Tester MXT 70, dan perubahan struktur mikronya diamati dengan menggunakan Scanning Electron Microscope, Dari hasil nifridasi, pada penembakan sebanyak 25 kali diperoleh angka kekerasan optimum sebesar (302,83 + 1,32) gf/gm2 yaitu pada jarak 10 cm terhadap elektroda, kekerasan baja naik + 21 % dibandingkan sebelum dinitridasi (251,2 gfljim2). Path penembakan sebanyak 50 kali diperoleh angka kekerasan optimum sebesar (357,85 + 7,91) grijam2 yaitu pada jarak 8 cm terhadap elektroda, dengan kenaikan kekerasan + 42%. Dan analisa struktur mikro swivel yang telah dinitridasi, terlihat perubahan struktur mikro yang ditunjukkan oleh naiknya nilai kekerasan. The nitridation has been done to the medium iron-carbon, with the purpose of increasing the hardness of its surface. The sample which is used has a dimension : 2,8 cm length, 1 cm width, and 1,5 mm thickness. The nitridation has been done by using plasma focus technics, with many varieties of the shooting frequency and the distance between the sample and electrode. The sample that has been nitridated, was tested on its hardness by Micro Hardness Tester MXT 70, and the change of the micro structure was observed by using Scanning Electron Microscope. The result of this nitridation, from 25 times shooting obtains a number of optimum hardness (302,83 + 1,32) gf/pm2 that's at 10 cm distance to electrode, the iron-carbon hardness up to + 21 % than before it was nitridated (251,2 Ann2). In 50 times shooting obtains a number of optimum hardness (357,85 + 7,91) gflim2 that's at 8 cm distance to electrode, the increase of hardness is + 42 %. From the micro structure analysis of the sample which is nitridated, it shows the change of micro structure which is shown by increasing of the hardness value.