Karakterisasi Ball Mill Import pada Industri Semen di Indonesia

Ratna Kartikasari, R. Soekrisno, M. Noer Ilman




Abstract


The purpose of this research is to investigate the characteristics of import Ball Mill which is used at cement mills in Indonesia. There were two kind of import Ball Mill from PT. Semen Gresik, Tbk that used in this research which are A type (Ø 30 mm) and B type (Ø 40 mm). Visual investigation, chemistry composition, distribution of hardness, and microstructure photograph was conducted characterize these ball mill. Visually, the import Ball Mill has rough surface, white coloring when cut off, and small cracks at all specimens. Type A ball mill contains of 2,934% C, 11,231% Cr, and 0,177% Mo, where type B Ball Mill contains of 2,693% C, 12,31% Cr, and 1,103% Mo. Both are martensitic white cast iron ASTM A532 Class II type A. The surface are harder then the its core. The highest hardness on the surface are 720,82 kg/mm2 (type A) and 746,5 kg/mm2 (type B), where as lowest hardness on the core are 631,1 kg/mm2 (type A) and 544,0 kg/mm2 (type B). Microstructure investigation shows Perlit, Cementit, and Martensit.


Abstract in Bahasa Indonesia :

Penelitian ini bertujuan untuk mengetahui karakteristik Ball Mill import yang digunakan oleh pabrik semen di Indonesia. Bahan yang digunakan adalah ball mill import di PT. Semen Gresik, Tbk dari 2 merk berbeda, yaitu merk A (f 30 mm) dan merk B (f 40 mm). Karakterisasi Ball Mill import dilakukan dengan pengamatan visual, uji komposisi kimia, uji distribusi kekerasan dan foto struktur mikro. Secara visual terlihat bahwa Ball Mill import memiliki permukaan kasar, hasil potongan berwarna keputihan dan terdapat retakan-retakan kecil pada semua specimen. Hasil uji komposisi kimia menunjukkan bahwa Ball Mill import f 30 mm mengandung 2,934% C, 11,231% Cr, dan 0,117% Mo sedangkan f 40 mm mengandung 2,693% C, 12,313% Cr dan 1,103 Mo, termasuk dalam kelompok Martensitic white cast iron ASTM A532 Class II Type A. Hasil uji distribusi kekerasan menunjukkan bagian permukaan lebih keras dibandingkan bagian pusat dengan nilai kekerasan tertinggi 720,82 kg/mm2 (f 30 mm) dan 746,5 kg/mm2 (f 40 mm) sedangkan nilai kekerasan terendah 631,1 kg/mm2 (f 30 mm) dan 544,0 kg/mm2 (f 40 mm). Hasil pengamatan foto struktur mikro menunjukkan bahwa struktur terdiri dari Perlit, Cementit dan Martensit.

Kata kunci: ASTM A532, bola penggiling, besi tuang putih martensitik.


Keywords


ASTM A532, ball mill, martensitic white cast iron.

Full Text: PDF

The Journal is published by The Institute of Research & Community Outreach - Petra Christian University. It available online supported by Directorate General of Higher Education - Ministry of National Education - Republic of Indonesia.

©All right reserved 2016.Jurnal Teknik Mesin, ISSN: 1410-9867

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