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"Studi mengenai perubahan mikrostruktur pada butir ferit dan pengaruhnya terhadap ketahanan korosi pada baja karbon rendah telah dilakukan. Thermomechanical processing (TMP) merupakan sebuah subjek baru dalam ilmu rekayasa material yang mengkombinasikan perlakuan dan temperatur proses terhadap material dengan tujuan mendapatkan material berkualitas tinggi. Dengan memberikan perlakuan canai pada temperatur hangat, akan terbentuk struktur butir ferit yang halus, yang membuat sifat mekanik meningkat, laju korosi menurun, dan kemampuan mengabsorbsi hidrogen juga ikut menurun. Uji polarisasi dan uji HIC dilakukan untuk mengukur laju korosi dan ketahanan penggetasan oleh hidrogen pada bagian spesimen yang searah dan tegak lurus dengan arah canai, dimana spesimen yang dilakukan pengujian adalah baja karbon rendah SS 400 tanpa deformasi dan dengan deformasi canai hangat. Besar deformasi reversible yang diberikan adalah 20%, 20% +20%, 20% +20% +20% and 20% +20% +20% +20% dengan ketebalan awal adalah ho 6 mm. Sebuah mekanisme baru dalam metode canai multi pass reversible juga dilakukan yang disebut metode canai double-side multi pass reversible. Dengan menggunakan metode canai double-side multi pass reversible, diharapkan butir ferit halus yang terbentuk akan terdistribusi seragam diseluruh bagian permukaan.

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Microstuctural changes of ferrite grains and its relationship with corrosion resistance in low carbon steel were investigated. Thermomechanical processing (TMP) is a new subject in material engineering which is combining treatment and temperature process to material in order to obtain high quality materials. By applying rolling deformation process in warm working temperature, low carbon steel will have fine ferrite grain structures made its mechanical properties increased, its corrosion rate decreased and also its ability to absorb hydrogen decreased.

Polarization test and HIC test were conducted to measure the corrosion rate and hydrogen embrittlement resistance on both parallel and perpendicular specimen to rolling direction (RD) orientation of as-received and plastic-strained warm rolling material as raw material of SS400 low carbon steel. The applied mechanisms of pass deformation are reversible which are 20%, 20% +20%, 20% +20% +20% and 20% +20% +20% +20% with initial thickness ho 6 mm. A new mechanism of multi pass rolling methods was also proposed which is double-side multi pass reversible. By applying double-side multi pass reversible, it is expected that fine ferrite grains will be distributed uniformly in all surface points."

"Industri pelat kuningan di Indonesia saat ini hanya menghasilkan pelat-pelat yang nilai tambahnya rendah, karena belum dikuasainya teknologi termomekanikal sebagai dasar rekayasa proses untuk pengembangan produk pelat, yang pada prinsipnya adalah rekayasa butir di dalam struktur mikro. Dalam penelitian disini akan dipelajari hubungan pengaruh kadar aluminium dibawah dan diatas 0,03% terhadap parameter proses anil cepat yaitu temperatur dan waktu tahan, terhadap Difraksi Sinar X, besar butir, struktur mikro, kekerasan, kekasaran dan mampu bentuknya, kemudian analisa dari hubungan tersebut, digunakan untuk mendapatkan kombinasi temperatur dan waktu tahan proses anil cepat, yang menghasilkan kemampuan bentuk optimal. Variabel dalam proses penelitian ini yaitu komposisi kadar aluminium memenuhi syarat (Al ≤ 0,03%) dan melebihi syarat (Al > 0,03%), pengaruh temperatur anil cepat yaitu 500°, 600° dan 700°C waktu tetap 3 menit, dan pengaruh waktu anil cepat yaitu 2,3 dan 4 menit temperatur tetap 600°C. Dari penelitian didapatkan kadar aluminium 0,16112% > 0,03% masih tergolong dalam kuningan 70/30 karena fasanya masih alfa, kemudian dengan semakin tingginya temperatur dan lamanya waktu anil cepat setelah pelat mengalami pengerolan dingin dengan reduksi 38%, terjadi penurunan besar butir rata-ratanya mengecil yaitu 11,742%, sedangkan penurunan kekerasan rata-ratanya membesar yaitu 51,05% berarti terjadi pertumbuhan butir, sehingga didapatkan temperatur dan waktu anil cepat optimal yaitu 600°C waktu 3 menit, kemudian diaplikasikan di pelat untuk menguji kemampuan bentuk melalui sampel uji tarik, ternyata elongasi, kekuatan tarik maksimal, koefisien pengerasan regang (n) dan anisotropi normal (r) mendekati referensi standar dan industri pengguna, untuk anisotropi planar (Δr) atau pengupingan sedikit diatas nilai nol. Kekasaran permukaan menurun dari pengerolan dingin ke proses anil cepat, akan tetapi distribusi kekasarannya masih tidak homogen. Dari pengerolan dingin melalui difraksi Sinar X didapat bidang (220) dan (111), setelah dianil terjadi penambahan satu bidang lagi yaitu (200).

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Currently brass sheet industry in Indonesia only produce low value added sheet product, because not yet understand the thermomechanical technology as the basic of process engineering for sheet product development. The basic process that is grain engineering in the sheet microstructure. In this research we will be studied the relation of aluminium content under and up specification 0,03%, to rapid annealing process parameter that is temperature and holding time, correlation to X Ray Diffraction, grain size, microstructure, hardness, and surface roughness, and then from this analysis relationship, applied to get combination of optimal temperature and rapid annealing process holding time, for getting the optimal sheet formability. Process parameter using in this research that is aluminium content below or over 0,03%, effect of anneal temperature such as 500°,600° and 700°C with fixed 3 minute holding time, and effect of anneal holding time such as 2,3 and 4 minute with fixed temperature of 600°C. Resulting from this research is got aluminium content that is 0,16112% > 0,03% still classify as brass 70/30 because only one phase in the microstructure that is alpha, then with increasing anneal temperature and holding time after the sheet experiences cold rolling with reduction 38%, exist mean grain size decreasing 11,742%, whereas mean hardness decreasing extend to 51,05%, these means happen enlarge of grain size, until got temperature and rapid anneal optimal that is 600°C with time 3 minute, then after apply to brass 70/30 sheet for testing sheet formability by tensile testing method. The results such as elongation, ultimate tensile strength, strain hardening coefficient (n), normal anisotropy (r) close to standard reference and user industry specification, for planar anisotropy (Δr) or earing tendency is little about zero. Although surface roughness declines from cold rolling to rapid annealing process, however distribution of its roughness still not homogen. From cold rolling resulting two plane such as (220) and (111), after that from rapid annealing process add one more plane that is (200) because crystal plane move to stabil condition after got cold rolling and rapis annealing."

"This book summarizes the results of experimental work on the development of technologies for the manufacture of sour service line pipe steels. It presents the latest theories on the mechanisms of cracking and factors affecting fracture resistance in H2S-containing media of low-alloy pipe steels. The authors propose methods for improving the quality of continuously cast slabs and show the effect of the chemical composition on the microstructure and properties of rolled plates for pipes. Considerable attention is paid to the metallurgical aspects of microstructure formation and its mechanical properties, as well as the enhancement and cracking resistance of sour service sheets under thermomechanical rolling with accelerated cooling. In brief, the book presents a cutting-edge overview of sour service sheet and pipe production."