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Journal articles on the topic 'Austenit'
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1
Abrianto Akuan. "Analisis Struktur Mikro dan Sifat Mekanik Baja Mangan Austenitik Hasil Proses Perlakuan Panas." Jurnal Teknik: Media Pengembangan Ilmu dan Aplikasi Teknik 7, no. 2 (2020): 90–99. http://dx.doi.org/10.26874/jt.vol7no2.284.
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Nilai kekerasan tertinggi yaitu 334.2HV untuk material baja mangan austenitik dihasilkan dari hasil proses perlakuan panas annealing. Semakin lambat laju pendinginan proses perlakuan panas (quenching, normalizing, annealing) material baja mangan austenitik akan meningkatkan nilai kekerasan material tersebut, yaitu (217.4 HV, 245.0 HV, 334.2 HV). Struktur mikro material baja mangan austenitik hasil perlakuan panas guenching adalah karbida dalam matrik austenit (γ), sedangkan hasil perlakuan panas normalizing dan annealing adalah karbida dalam matrik ferrit (ɑ).
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Farhan, Farhan, Bukhari Bukhari, Hamdani Hamdani, Ilyas Yusuf, and Zuhaimi Zuhaimi. "PENGARUH TEMPERATUR PEMANASAN (AUSTENISASI) PERLAKUAN PANAS QUENCHING TERHADAP KEKERASAN DAN STRUKTUR MIKRO BAJA ST 60." Jurnal Mesin Sains Terapan 5, no. 1 (2021): 1. http://dx.doi.org/10.30811/jmst.v5i1.2135.
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Sehubungan dengan semakin meningkatnya perkembangan dunia industri dan disertai dengan kemajuan teknologi yang sangat pesat. Pada masa sekarang kebutuhan manusia tidak lepas dari suatu unsur, yaitu baja. Baja ST 60 adalah salah satu jenis baja yang memiliki standard buatan negara German, yaitu Deutsches Institut fur Normung (DIN). Baja ST 60 ini dapat diberikan perlakuan panas untuk meningkatkan sifat mekaniknya. Penelitian ini bertujuan untuk mengetahui pengaruh temperatur austenit terhadap kekerasan dan struktur mikro dari baja ST 60 ini. Temperatur austenit yang diambil adalah 850˚C, 900˚C, dan 950˚C dengan waktu penahanan 90 menit dan menggunakan air sebagai media pendingin (Quenching). Setelah melakukan proses perlakuan panas pada baja ST 60, dilakukan pengujian kekerasan metode Rockwell dan pengamatan struktur mikro. Hasil pengujian kekerasan pada kondisi normal sebesar 55.70 HRC dan belum menghasilkan fasa martensit. Pada temperatur austenit 850˚C nilai kekerasannya 71.20 HRC dan fasa martensit telah muncul. Namun pada temperatur 900˚C nilai kekerasannya 75.20 HRC dengan banyaknya fasa martensit yang sudah terbentuk. Dari penelitian ini didapat temperatur austenit yang optimum pada temperaturs 850˚C sampai 900˚C. Kata Kunci : Baja ST 60, Heat Treatment, Quenching, Kekerasan, Struktur Mikro
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Ihlas, Apriardi. "PENGGETASAN LOGAM CAIR PADA CAPILLARY TUBE BAJA TAHAN KARAT 316." Jurnal Teknologi Bahan dan Barang Teknik 5, no. 1 (2015): 29. http://dx.doi.org/10.37209/jtbbt.v5i1.56.
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Capillary tube adalah komponen yang berfungsi mengalirkan larutan kimia (scale inhibitor) ke dalam sumur minyak yang berpotensi membentuk kerak. Telah terjadi penyumbatan (clogging) dan retak-retak pada komponen capillary tube yang berbahan baja tahan karat austenit 316. Pemasangan komponen tersebut berada dalam satu kesatuan unit dengan komponen lain yang bernama centriline cel flat. Untuk mengetahui lebih lanjut penyebab terjadinya kerusakan, dilakukan serangkaian pemeriksaan dan pengujian. Pemeriksaan tersebut meliputi: data awal dan kronologi, visual, metalografi (makro dan mikro), dan Scanning Electron Microscopy/ Energy Dispersive X-ray Spectroscopy (SEM-EDS). Hasil pemeriksaan menunjukkan adanya penetrasi seng pada permukaan tube. Penetrasi seng yang mencair mencapai batas butir akan membentuk senyawa intermetallic seng-nikel yang akan mengakibatkan terjadinya perubahan fasa austenit menjadi ferit. Perubahan internal stress akibat perubahan volum fasa inilah yang menyebabkan terjadinya retakan di batas butir.Kata kunci: penggetasan logam cair, baja tahan karat austenit, baja galvanis, retakan batas butir
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Alhamidi, Ali. "Proses Quenching and Partitioning Terhadap Sifat Mekanik Baja Karbon Medium." Jurnal Rekayasa Mesin 15, no. 2 (2020): 118. http://dx.doi.org/10.32497/jrm.v15i2.1869.
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<p>Baja WRM 1045 adalah baja karbon sedang yang menawarkan sifat mekanik yang baik dan diterapkan untuk industri otomotif seperti poros engkol. Menurut JIS G4051 bahwa sifat mekanik untuk poros engkol diharapkan memiliki kekuatan luluh ~ 490 MPa, kekuatan tarik minimum, dan perpanjangan 686 MPa dan 17%. Dalam penelitian ini, baja WRM 1045 diproses melalui proses Quenching and Partitioning (Q&P). Itu dilakukan dengan variasi waktu penahanan 30 dan 60 menit selama austenitisasi dan suhu partisi 225, 250, 275, dan 300 ℃. Pengujian tarik, uji kekerasan dan metalografi dilakukan untuk menentukan sifat mekanik dan struktur mikro baja WRM KS1045. Hasil penelitian menunjukkan bahwa sifat mekanik menurun dengan meningkatnya suhu partisi dan waktu penahanan austenit. Semakin tinggi sifat mekanik dicapai setelah waktu tahan austenit 60 menit dan suhu partisi 275 ℃ dengan kekuatan luluh 520,70 MPa, kekuatan tarik 784,63 MPa, perpanjangan 15%, dan kekerasan 93,33 HRB. Analisis struktur mikro optik terdiri dari martensit dan retensi austenit setelah proses Q&P.</p>
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Poech, Max-Hermann, and Hellmut Fischmeister. "Mechanische Eigenschaften von Martensit-Austenit-Modellegierungen." International Journal of Materials Research 83, no. 3 (1992): 176–82. http://dx.doi.org/10.1515/ijmr-1992-830307.
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Ridlo, Faried Miftahur, Permana Andi Paristiawan, and Mukhlis Agung Prasetyo. "Pengaruh Variasi Holding Time dan Media Pendingin pada Proses Solution Treatment terhadap Kekerasan dan Ketangguhan Paduan Baja Fe12Mn1,5Mo." Metal Indonesia 42, no. 2 (2020): 77. http://dx.doi.org/10.32423/jmi.2020.v42.77-85.
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Baja mangan austenitik merupakan baja yang digunakan secara luas pada industri tambang dan mineral karena memiliki ketahanan aus dan ketangguhan yang tinggi. Secara umum, baja mangan austenitik yang dibuat melalui proses pengecoran memiliki kecenderungan getas dengan ketangguhan yang rendah karena terbentuknya formasi karbida. Proses solution treatment diikuti dengan pendinginan cepat menjadi hal penting untuk melarutkan karbida sehingga menjamin terbentuknya struktur full austenit pada temperatur kamar. Penelitian ini bertujuan untuk mengetahui pengaruh variasi holding time dan media pendingin pada proses solution treatment terhadap kekerasan dan ketangguhan paduan baja Fe12Mn1.5Mo. Pada penelitian ini, karakteristik baja Fe12Mn1.5Mo hasil cor diinvestigasi lebih lanjut setelah dilakukan proses solution treatment dalam dua tahap, yaitu memanaskan dari temperatur ruang sampai 700oC dengan holding time 3 jam, kemudian dinaikkan sampai temperatur 1000 oC dengan variasi holding time selama 1 jam, 2 jam dan 3 jam diikuti dengan quenching menggunakan 3 media pendingin berbeda (air, larutan garam 1.5% dan 3%). Pada pendinginan menggunakan larutan garam 1.5% dan 3% menunjukkan bahwa semakin lama holding time, maka nilai kekerasan dan nilai impak juga semakin meningkat. Sementara itu, spesimen yang didinginkan menggunakan air menghasilkan nilai yang berfluktuasi untuk kedua sifat mekanik. Nilai kekerasan tertinggi sebesar 344 BHN pada variasi holding time 2 jam diikuti dengan pendinginan air, sementara nilai impak tertinggi sebesar 73.7 J/cm2 dihasilkan pada variasi holding time 1 jam dengan pendinginan air. Nilai impak terendah sebesar 48.8 J/cm2 dihasilkan pada variasi holding time 1 jam dengan pendinginan larutan garam 3%. Hasil metalografi menunjukkan bahwa struktur mikro matriks austenit yang mengakibatkan nilai kekerasan yang rendah sedangkan karbida tak terlarut yang terdispersi di batas butir dan di dalam butir yang mengakibatkan nilai kekerasan yang tinggi. Di sisi lain, Proses solution treatment yang berlangsung kurang sempurna berakibat pada menurunnya ketangguhan karena terbentuknya presipitasi karbida.
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Grajcar, A., P. Skrzypczyk, and D. Wozniak. "Thermomechanically Rolled Medium-Mn Steels Containing Retained Austenite/ Walcowane Termomechanicznie Stale Średniomanganowe Zawierające Austenit Szczątkowy." Archives of Metallurgy and Materials 59, no. 4 (2014): 1691–97. http://dx.doi.org/10.2478/amm-2014-0286.
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Abstract Chemical composition of four medium-Mn steels containing a various Mn content (3 and 5%) have been proposed in the present work. The two steels are base steels whereas the other two contain Nb microaddition. Thermomechanical rolling tests of 3.3 mm sheets have been carried out using a semi-industrial hot strip rolling line. Detailed investigations of the identification of structural constituents using light microscopy and scanning electron microscopy techniques have been performed. X-ray method has been applied to determine an amount of retained austenite and its C content. Significant microstructural parameters were revealed using an EBSD technique. It was found that the Mn addition affects strongly a microstructure type, stability of retained austenite and mechanical properties determined with a static tensile test. The steels containing 3% Mn are characterized by a good combination of strength and ductility whereas the tensile strength up to 1300 MPa is possible to obtain for the higher Mn content steels.
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Bublíková, Dagmar, Hana Jirková, Štěpán Jeníček, and Josef Káňa. "Q&P process in press-hardening of 42SiCr steel." Acta Metallurgica Slovaca 24, no. 1 (2018): 52. http://dx.doi.org/10.12776/ams.v24i1.967.
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<p><span style="vertical-align: inherit;"><span style="vertical-align: inherit;">Jednou z dnešních pokročilých cest tepelné úpravy ocelí s vysokou pevností je proces Q & P, který poskytuje vysokou pevnost v kombinaci s dobrou tažností. </span><span style="vertical-align: inherit;">Výsledná mikrostruktura je kombinací martenzitu a malých frakcí bainitu a zadrženého austenitu. </span><span style="vertical-align: inherit;">Zadržený austenit má podobu tenkých jehel, které přiléhají k martenzitovým lištám. </span><span style="vertical-align: inherit;">Použití tohoto způsobu v průmyslové praxi je komplikované potřebou udržení při rozdělovací teplotě, když se zadaný austenit stabilizuje migrací uhlíku z super-nasyceného martenzitu. </span><span style="vertical-align: inherit;">Inženýři proto hledají procesní cesty, při nichž přerušení chladicího procesu při určité teplotě a udržení při této teplotě nepředstavují technologické problémy. </span></span></p><span style="vertical-align: inherit;"><span style="vertical-align: inherit;">Jednou z dostupných možností je vytvrzování lisováním, které se často zabývá ošetřením částí těla vozidla. </span><span style="vertical-align: inherit;">Ocel 42SiCr, která je legována manganem, křemíkem a chrómem, byla Q & P zpracována za použití experimentálních sekvencí s různými teplotami kalení a dělení. </span><span style="vertical-align: inherit;">Doba namáčení a teplota a rychlost chlazení byly shodné s parametry používanými v reálných procesech. </span><span style="vertical-align: inherit;">Správně zvolené parametry vedly k martensiticko-bainitickým mikrostrukturám s částí zadrženého austenitu, maximální pevností přibližně 2000 MPa a </span><span style="vertical-align: inherit;">protažením </span><span style="vertical-align: inherit;">A </span></span><sub><span style="vertical-align: inherit;"><span style="vertical-align: inherit;">20</span></span></sub><span style="vertical-align: inherit;"><span style="vertical-align: inherit;"> více než 10%.</span></span>
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Inagaki, Hirosuke. "Annealing Twins in Deformed Austenite of a Low-Carbon Steel / Glühzwillinge im verformten Austenit eines kohlenstoffarmen Stahls." International Journal of Materials Research 81, no. 3 (1990): 174–80. http://dx.doi.org/10.1515/ijmr-1990-810303.
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Rohmah, Miftakhur. "PENGARUH PENEMPAAN DAN PERLAKUAN PANAS TERHADAP SIFAT MEKANIK DAN KETAHANAN KOROSI PADA MODIFIKASI BAJA LATERIT A-588." Metalurgi 36, no. 1 (2021): 33. http://dx.doi.org/10.14203/metalurgi.v36i1.579.
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High strength low alloy (HSLA) yang diaplikasikan menjadi baja tahan cuaca merupakan terobosan terbaru untuk menghasilkan sifat mekanik dan ketahanan korosi yang tinggi. Modifikasi Baja Laterit dengan penambahan kadar nikel yang diterapkan proses termomekanikal (TMCP) berupa kombinasi proses penempaan panas dan perlakuan panas menjadi fokusan penelitian ini. Sampel yang digunakan merupakan Baja Laterit A-588 hasil investment casting yang telah ditambahkan kadar nikel sebesar 1, 2, dan 3% kemudian diproses penempaan panas dengan pembebanan 100 ton pada temperatur 1050 ℃. Nikel berfungsi sebagai penstabil austenit. Variabel perlakuan panas yang digunakan yakni (1) langsung pendinginan udara, (2) dilanjutkan proses pemanasan pada temperatur 750 ℃ yang diikuti pendinginan cepat. Karakterisasi material menggunakan uji metalografi, uji keras, uji tarik, dan uji polarisasi. Pada sampel tempa panas+pendinginan udara, pertambahan kadar nikel hingga 3% mempengaruhi nilai fraksi fasa ferrit-perlit yang terbentuk, pertambahan ukuran butir hingga ±0,1 mm, penurunan kekerasan hingga 185,22 BHN, penurunan kekuatan hingga 554 MPa, dan pertambahkan elongasi sebesar 29.1%. Sedangkan pada sampel tempa panas+perlakuan panas dengan pendinginan air, pertambahan nikel hingga 3% menyebabkan terbentuknya fasa dislokasi lath martensit+ferrit+retained austenite, penurunan kekerasan hingga 236,18 BHN, penurunan kekuatan hingga 852 MPa, penurunan elongasi hingga 24,7%. Fasa retained austenite memiliki efek merusak pada sifat mekanis.
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Fuchs, Axel. "Vorgänge im Austenit bei der Walzung von mikrolegierten Baustählen." Steel Research 57, no. 5 (1986): 226–28. http://dx.doi.org/10.1002/srin.198600757.
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Paju, M., H. Viefhaus, and H. J. Grabke. "Korngrenzensegregation des Phosphors im Austenit und Einfluß von Kohlenstoff." Fresenius' Zeitschrift für analytische Chemie 329, no. 2-3 (1987): 327–30. http://dx.doi.org/10.1007/bf00469164.
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Ismy, Adi Saputra. "Karburisasi baja ST 37 dengan media arang batok kelapa." Jurnal POLIMESIN 7, no. 1 (2009): 563. http://dx.doi.org/10.30811/jp.v7i1.1340.
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Salah satu cara untuk memperkeras permukaan logam agar tahan dari keausan dengan bagian inti tetap ulet dilakukan dengan proses karburisasi, yaitu suatu proses penambahan unsur karbon pada baja karbon rendah dengan jalan membuat lingkungan yang tepat pada temperatur dimana fase austenit terjadi. Penelitian ini bertujuan untuk mengetahui pengaruh penggunaan media karbon arang batok kelapa terhadap hasil kekerasan material uji (baja karbon rendah). Proses perlakuan yang digunakan pada penelitian ini adalah dengan memanaskan material didalam pack atau kotak yang berisi media arang batok kelapa dengan variasi ukuran butir media (CX200), (200xC 300), (C2300), hingga mencapai temperatur austenisasi (950 C) dan ditahan pada temperatur tersebut (holding time) dengan variasi selama 1 jam, 2 jam, 3 jam, 4 jam dan 5 jam. Kemudian material uji didinginkan diudara. Penelitian menggunakan 15 spesimen dan arang batok kelapa sebagai media karbon. Hasil yang diperoleh dari penelitian ini menunjukkan bahwa penggunaan arang batok kelapa sebagai media karbon dapat meningkatkan kekerasa. Dibandingkan dengan kekerasan awal, hasil yang dicapai dari penelitian ini terjadi peningkatan kekerasan.Kata kunci : Karburisasi, Temperatur Austenite, keausan, kekerasan
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Sungkono, Sungkono, and Sri Ismarwanti. "PENGARUH PERLAKUAN PANAS TERHADAP PERILAKU TARIK DAN STRUKTUR MIKRO BAJA TAHAN KARAT AISI 304 PADA DAERAH SENSITISASI 600 – 700 °C." Urania : Jurnal Ilmiah Daur Bahan Bakar Nuklir 27, no. 3 (2021): 123. http://dx.doi.org/10.17146/urania.2021.27.3.6570.
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PERILAKU TARIK DAN STRUKTUR MIKRO BAJA TAHAN KARAT AISI 304 PASCA PERLAKUAN PANAS PADA DAERAH SENSITISASI 600 – 700 °C. Baja tahan karat AISI 304 digunakan sebagai komponen struktur reaktor daya tipe LWR. Dalam pembuatan komponen struktur, kualitas sambungan lasan SS 304 ditentukan oleh proses pendinginan dari temperatur austenit ke sensitisasi. Tujuan penelitian adalah mengetahui karakter kekuatan tarik, kekerasan dan struktur mikro SS 304 pada daerah sensitisasi 600-700 °C. Metoda penelitian yang digunakan adalah pengujian komposisi kimia, tarik, kekerasan, dan struktur mikro yang mengacu pada ASTM. Hasil penelitian menunjukkan bahwa kekuatan tarik SS 304 pasca perlakuan sensitisasi pada (600 °C, 30- 60 menit) dan (700 °C, 30-90 menit) relatif sama dan lebih rendah dibandingkan tanpa perlakuan panas, sedangkan pada (600 °C, 90 menit) relatif sama dengan sampel tanpa perlakuan panas. Struktur mikro SS 304 terdiri atas fasa ferit-d dan austenit serta presipitat khrom karbida. Kuantitas presipitat di batas butir menurun dengan bertambahnya temperatur dan waktu penahanan. Kekerasan pasca perlakuan sensitisasi pada 600 - 700°C relatif sama di base metal, dekat patahan dan daerah patahan. Ketangguhan retak terbaik diperoleh pada sampel SS 304 dengan perlakuan (700 °C, 90 menit).Kata kunci: baja tahan karat, sensitisasi, kekuatan tarik, kekerasan, struktur mikro, presipitat.
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Hübner, W. "Untersuchungen zur Austenit-Martensit-Umwandlung bei tribologischer Beanspruchung in tiefkalten Medien." Materialwissenschaft und Werkstofftechnik 31, no. 8 (2000): 784–86. http://dx.doi.org/10.1002/1521-4052(200008)31:8<784::aid-mawe784>3.0.co;2-t.
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Poech, Max-Hermann. "Mechanische Eigenschaften von Martensit-Austenit-Modellegierungen Teil I: Gefügeanordnung und Bruchzähigkeit." International Journal of Materials Research 83, no. 6 (1992): 379–85. http://dx.doi.org/10.1515/ijmr-1992-830603.
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Lu, Lilin, Jiaqi Ni, Zhixian Peng, Haijun Zhang, and Jing Liu. "Hydrogen Embrittlement and Improved Resistance of Al Addition in Twinning-Induced Plasticity Steel: First-Principles Study." Materials 12, no. 8 (2019): 1341. http://dx.doi.org/10.3390/ma12081341.
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Understanding the mechanism of hydrogen embrittlement (HE) of austenitic steels and developing an effective strategy to improve resistance to HE are of great concern but challenging. In this work, first-principles studies were performed to investigate the HE mechanism and the improved resistance of Al-containing austenite to HE. Our results demonstrate that interstitial hydrogen atoms have different site preferences in Al-free and Al-containing austenites. The calculated binding energies and diffusion barriers of interstitial hydrogen atoms in Al-containing austenite are remarkably higher than those in Al-free austenite, indicating that the presence of Al is more favorable for reducing hydrogen mobility. In Al-free austenite, interstitial hydrogen atoms caused a remarkable increase in lattice compressive stress and a distinct decrease in bulk, shear, and Young’s moduli. Whereas in Al-containing austenite, the lattice compressive stress and the mechanical deterioration induced by interstitial hydrogen atoms were effectively suppressed.
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Azmal, Azmal, Dwi Handoko, Masril Masril, and Eligius Ilhamdi. "PENGARUH VARIASI TEMPERATUR AUSTENIT PENGUJIAN JOMINY TEST PADA SIFAT HARDENABILITY BAJA ST 90." Jurnal Vokasi 16, no. 2 (2021): 74–79. http://dx.doi.org/10.31573/vokasi.v16i2.403.
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The purpose of this research is to obtain information about the hardness value (hardening) and changes in microstructure as well as changes in the properties of the material at a temperature variation of 600℃ to 900℃. The method used in this study is an experimental method, where the material used is ST.90 steel, and Jominy testing. 5 samples were made at each temperature 22℃, 600℃, 700℃, 800℃, and 900℃ with the type of heat treatment in the hardening process. The test results for Vickers hardness decreased by an average of 33.99 HV or 31% and the carbon content decreased by an average of 0.19. or 48% of the normalizing process is not done. Based on the data above, it shows that the results of the Vickers hardness test and chemical composition with the hardening process of ST.90 steel, which are heated at 600℃, 700℃, 800℃, and 900℃ respectively, each temperature is reached and stopped with 60 minutes. In order for phase transformation to occur in all parts of the material, then the cooling process is carried out using the Jominy test, showing the mechanical strength, namely the Vickers hardness test decreases by 23% and the carbon content decreases at 37%.
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Sussman, Matthew. "Austen, Gaskell, and the Politics of Domestic Fiction." Modern Language Quarterly 83, no. 1 (2022): 1–26. http://dx.doi.org/10.1215/00267929-9475004.
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Abstract This essay offers a significant reconceptualization of Jane Austen’s influence on political novelists of the mid-nineteenth century by examining Elizabeth Gaskell’s extensive use of Pride and Prejudice (1813) in her novel North and South (1855). At a moment when the political dimensions of Austen’s fictions were fading to obscurity, Gaskell drew on Austen’s portrayal of domestic relationships to underscore their relevance to “public” problems. On this view, the Austenian courtship plot does not contain political anxieties so much as animate them, with the logic of complementary coupling providing a formal and thematic model for the dialectical engagements necessary for navigating social conflict. At the same time, Gaskell uses Austenian motifs to dramatize the “marriageability” of different generic frameworks during a time of regional fragmentation while also envisioning Austen as a parental figure whose legacy called for continuing negotiation.
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Yanuar, Padang, Iman Mujiarto, and Yoeli Janto. "PENINGKATAN NILAI KEKERASAN BAJA C-Mn DENGAN METODE QUENCHING DAN TEMPERING." Simetris: Jurnal Teknik Mesin, Elektro dan Ilmu Komputer 9, no. 1 (2018): 61–66. http://dx.doi.org/10.24176/simet.v9i1.1706.
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Perlakuan panas quenching dan tempering telah lama diterapkan pada baja untuk menghasilkan kombinasi antara kekuatan dan ketangguhan yang baik dengan struktur mikro martensite. Sifat baja seperti kekerasan yang tinggi dengan kombinasi ketangguhan yang baik membuat baja menjadi pilihan utama untuk material armor (tahan peluru). Tujuan penelitian ini melakukan kajian perubahan sifat mekanis baja komersial (baja C-Mn) akibat proses quenching dan tempering untuk dapat diaplikasikan sebagai baja armor. Pemanasan pada temperatur austenit 900 °C dengan penahanan selama 45 menit kemudian dilakukan quenching pada media air dilanjutkan tempering 175 °C selama 30 menit didapatkan nilai kekerasan tertinggi sebesar 546 BHN dengan dominasi struktur mikro martensite yang terbentuk.
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Jaeger, Fabian, Alessandro Franceschi, Holger Hoche, Peter Groche, and Matthias Oechsner. "Optimierung des Eigenspannungszustands kaltfließgepresster austenitischer Stähle durch einen kontrollierten Ausstoßvorgang." Forschung im Ingenieurwesen 85, no. 2 (2021): 691–702. http://dx.doi.org/10.1007/s10010-021-00483-w.
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ZusammenfassungAusgehend von vorherigen Ergebnissen zur Prozessoptimierung fließgepresster Proben aus dem austenitischen Werkstoff 1.4404 mittels einer aktiven Prozessführung zur Verbesserung des Eigenspannungszustands, wurde das gleiche Verfahren auf den metastabilen austenitischen Werkstoff 1.4307 angewandt. Es wurden neue Erkenntnisse erwartet, da dieses Material bereits bei geringen Umformgraden zur Bildung von verformungsinduziertem Martensit neigt. Zum Vergleich der erwarteten Optimierung des Eigenspannungszustands wurden konventionell fließgepresste Proben hegestellt und spannungsarmgeglüht.Es wurde gezeigt, dass die Reduktion der Zugeigenspannungen durch die aktive Prozessführung beim 1.4307 insbesondere in der martensitischen Phase auftritt, während diese beim 1.4404 im Austenit erfolgt. Durch einen zusätzlichen Prozessschritt der Wärmebehandlung konventionell fließgepresster Proben werden ebenfalls Zugeigenspannungen abgebaut. Allerdings zeigt die Kaltumformung mit aktiver Prozessführung ein höheres Potenzial zur Verbesserung des Eigenspannungszustands.
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Inagaki, Hirosuke. "Formation and Annihilation of Annealing Twins in the Austenite of a Low Carbon Steel / Bildung und Auflösung von Glühzwillingen im Austenit eines kohlenstoffarmen Stahls." International Journal of Materials Research 81, no. 2 (1990): 119–29. http://dx.doi.org/10.1515/ijmr-1990-810209.
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Soemowidagdo, Arianto Leman, and Tiwan Tiwan. "Methods in Making Steel-Copper Sandwich Laminates Materials." Jurnal Dinamika Vokasional Teknik Mesin 4, no. 2 (2019): 144–49. http://dx.doi.org/10.21831/dinamika.v4i2.27400.
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This research is aimed at developing a method to make steel-copper sandwich laminate materials. The research focused on the method of developing the sandwich material. In a method I, the steel plate arrangement is heated up to austenite temperature and subsequently, a molten copper is poured into it. In method II, the steel plate arrangement is immersed into a molten copper in a temperature of 1200 °C. The result shows that in the method I, the diffusion on the interface layer of steel-copper sandwich laminate is unemployed because of an occurrence of oxidation on the steel surface. On the contrary, in method II the diffusion on the interface of steel-copper sandwich laminate is indicated by higher shear stress, which is 231.88 N/mm2. However, the immersing method needs to be improved to give better products, since cavities caused by trapped air still exist and are reducing the quality of the laminates.Penelitian ini ditujukan untuk mengembangkan metode pembuatan laminat baja-tembaga. Penelitian difokuskan pada metode pembuatan laminat. Pada metode I, susunan pelat baja dipanaskan hingga suhu austenit dan kemudian tembaga cair dituangkan. Metode II adalah merendam susunan pelat baja ke dalam tembaga cair bersuhu 1200 0C. Hasil penelitian menunjukkan bahwa pada metode I tidak terjadi difusi pada lapisan antarmuka laminat baja-tembaga karena permukaan baja mengalami oksidasi saat dipanaskan. Sebaliknya, metode II menunjukkan terjadi difusi pada antarmuka laminat baja-tembaga dengan tegangan geser tertinggi 231,88 N/mm2. Namun, metode II harus diperbaiki untuk memberikan produk yang lebih baik karena masih terdapat rongga akibat udara yang terjebak dan mengurangi kualitas laminat.
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Feng, Yun Li, Shao Qiang Yuan, and Meng Song. "Microstructure Evolution of Undercooled Austenite during Deformation for Medium-Carbon Si-Mn Steel." Materials Science Forum 704-705 (December 2011): 903–6. http://dx.doi.org/10.4028/www.scientific.net/msf.704-705.903.
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The microstructure evolution of a medium-carbon Si-Mn steel during deformation of undercooled austenite at different degree of deformation, temperatures and strain rates has been investigated by means of a hot compression simulation test, metallographic microscope, scanning electron microscope and transmission electron microscopy. Also, the mechanism of carbide spheroidized during deformed process has been discussed. The experiment results demonstrate that the process of evolution experienced three stages: that is, strain-induced transformation, austenite eutectoid decomposed to carbides and ferrite matrix, and spheroidization of pearlite at the range of A3-Ar3. The austenitic grains would be refined for the extra-product of ferrite above the Ar3. The eutectoid reaction was induced on the grain boundaries of ferrite and non-transformed austenite and deformation bands with the increasing volume of deformation. An optimum combination of deformation temperature and strain rate is important to obtian the dulplex microstructure consisting of ultrafine ferrites and dispersed carbide particles. The fine spheroidized microstructures are obtained while the deformed temperature reaches 650°C with ≥1.0, meanwhile, The carbides precipate in globular and shot-rod shapes. Keywords: Medium-carbon Si-Mn steel, Undercooled austentite, Microstructure evolution, Deformation induced transformation, Carbide spheroidization
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Ismy, Adi Saputra. "Hardening pada baja aisi C 1045." Jurnal POLIMESIN 3, no. 2 (2019): 217. http://dx.doi.org/10.30811/jpl.v3i2.1450.
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Sifat mekanik suatu logam tidak hanya tergantung dari komposisi kimia; tetapi juga pada struktur mikro dan proses perlakuan akhir. Pengerasan (hardening) adalah salah satu bentuk perlakuan panas dimana pengerasan dilakukan dengan memanaskan baja di daerah austenit, kemudian didinginkan cepat. Untuk itu telah disiapkan 15 buah. material uji baja AISI CI045 dengan pengaruh perbedaan temperature austeniusasi 800,850, 900, 950, 1000° C dan media pendingin air, oli SAE 20/40 dan emulsi Satu bual: material yang tidak dikeraskan digunakan sebagai pembanding peningkaian kekerasan. Komposisi karbon pada baja AISI CI045 adalah 0,43 - 0,50%. Hasil penelitian memperlihatkan bahwa kecenderungan peningkatan kekerasan terjadi tidak hanya dipengaruhi oleh naiknya temperature pemanasan tetapi juga laju pendinginan, dimana kekerasan optimum diperoleh pada temperature 850°C, holding time 15 menit dan pendinginan air, yaitu HV = 572,2. Kekerasan maksimum dengan media pendingin emulsi diperoleh nilai kekerasan HV = 427,8 juga pada temperature 950° C.
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Berecz, Tibor, and Peter J. Szabo. "Crystallographic relations during decomposition of the ferritic phase by isothermal ageing of duplex stainless steel." Journal of Applied Crystallography 46, no. 1 (2012): 135–41. http://dx.doi.org/10.1107/s0021889812044536.
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In highly alloyed and duplex stainless steels the range of alloying elements leads to many different phases precipitating at higher temperatures. Duplex stainless steels consist of almost equal ratios of austenite and ferrite, and between 923 and 1273 K the ferrite begins decomposing into secondary austenite (γ2) and the σ phase. Several orientation relations between the austenitic, ferritic and σ phases have been determined by other researchers. The calculation and testing of mathematical expressions for these orientations are important for a close understanding of changes in duplex steel hardness, ductility, and other qualitative measures imposed by annealing or heat ageing. The method described in this article also offers an approach for determining parent phase orientations from inherited orientations in other metallic microstructures. When the orientation relations of adjacent grains calculated from mathematical equations and those measured by electron backscatter diffraction were compared, naturally it was found that the average orientation differs less between grains that inherit matrix structure from common parents. However, it was also found that the degree of difference depended on the variants involved in the orientations. This phenomenon can be explained by features of the microstructure and decomposition of the ferritic phase: initially the microstructure contains only primary austenite (γ1) and ferrite, then after a while it contains [beside primary (γ1) austenite] increasing amounts of secondary (γ2) austenite and the σ phase, and decreasing amounts of ferrite. The presence of two variants of austenite makes it difficult to verify parent relations for secondary (γ2) austenites.
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Inagaki, Hirosuke. "Nucleation and Growth of Proeutectoid Ferrite in the Deformed Austenite of a Low Carbon Steel / Keimbildung und Wachstum von proeutektoidem Ferrit in verformtem Austenit eines kohlenstoffarmen Stahls." International Journal of Materials Research 80, no. 7 (1989): 476–83. http://dx.doi.org/10.1515/ijmr-1989-800703.
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Kartika, Ika. "PENGARUH PENAMBAHAN MANGAN TERHADAP SIFAT MAMPU TEMPA PADUAN Co-35Cr-5Mo UNTUK APLIKASI IMPLAN [The Effect of Mn Addition on Forging Ability Of Co-35Cr-5Mo Alloy for Implant Applications]." Metalurgi 27, no. 2 (2016): 95. http://dx.doi.org/10.14203/metalurgi.v27i2.144.
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IntisariPENGARUH PENAMBAHAN MANGAN TERHADAP SIFAT MAMPU TEMPA PADUAN Co-35Cr-5Mo UNTUK APLIKASI IMPLAN. Paduan Co-Cr-Mo dalam aplikasinya lebih banyak digunakan sebagaimaterial implan seperti pengganti tempurung atau sambungan tulang pinggul. Penambahan Ni dalam paduantersebut akan meningkatkan sifat mampu bentuknya, akan tetapi unsur nikel bersifat alergi terhadap tubuhmanusia. Oleh karenanya mangan akan dicoba untuk dapat menggantikan fungsi unsur nikel dalam paduan Co-Cr-Mo sebagai paduan implan. Pada penelitian ini akan dipelajari sifat mampu tempa dari paduan Co-35Cr-5Motanpa dan dengan penambahan Mn secara bervariasi sebesar 0,2-0,4-0,6-0,8-1(% berat). Diagram fasa daripaduan Co-35Cr-5Mo-xMn (x=0-20 % berat) dikalkulasi dengan menggunakan data base dalam Thermo-Calc.Ingot paduan Co-35Cr-5Mo-xMn (x=0-1 % berat) diperoleh melalui proses peleburan dan pemaduanmenggunakan tungku busur listrik dalam kondisi vakum pada temperatur di atas 1400 ºC. Proses homogenisasikemudian dilakukan menggunakan tungku vakum yang dialiri gas argon dengan kemurnian tinggi padatemperatur 1200 ºC selama 24 jam. Hasil proses tempa pada T =1250 ºC menunjukkan bahwa ingot paduan Co-35Cr-5Mo-0,4Mn tidak menghasilkan retak yang sangat signifikan bila dibandingkan dengan paduan tanpa dandengan variasi penambahan mangan lainnya. Hasil XRD menunjukkan bahwa fasa γ (fcc), fasa ε (hcp) dan fasaσ terkandung pada semua paduan Co-35Cr-5Mo-xMn (x=0-1 % berat). Hasil metalografi memperlihatkanadanya presipitasi fasa σ dalam batas butir austenit, dan beberapa striasi dalam butir austenit. Striasidimungkinkan adalah fasa ε dan kembaran deformasi. Dari hasil penelitian ini dapat disimpulkan bahwa paduanCo-35Cr-5Mo-0,4Mn memiliki sifat mampu tempa yang baik. Striasi dan adanya fasa σ mengarah terhadaprendahnya sifat mampu tempa dari paduan tersebut.Kata kunci : Paduan Co-35Cr-5Mo-xMn (x=0-1 % berat), Material implan, Variasi penambahan Mn, Sifatmampu tempa, Striasi, fasa γ (fcc), Fasa σ, Fasa ε (hcp)AbstractTHE EFFECT OF Mn ADDITION ON FORGING ABILITY OF Co-35Cr-5Mo ALLOY FOR IMPLANTAPPLICATIONS. The applications of Co-Cr-Mo alloys are widely used as an implant material such as kneeand hip joint. Subject of this research relates to the forge ability of Co-35Cr-5Mo without and with variousaddition of Mn approximately 0.2-0.4-0.6-0.8-1 (weight %). Co-35Cr-5Mo-xMn (0-20 weight %) phase diagramis calculated using data base in the Thermo-Calc software. Co-35Cr-5Mo-xMn (0-1 weight %) alloy ingots areobtained through melting and solidifying process by using tri arc melting in vacuum condition at temperatureabove 1400 ºC. Homogenizing is carried out using vacuum furnace with high purity argon gas at temperature1200 ºC for 24 h. After forging process at T = 1250 ºC, Co-35Cr-5Mo-0.4Mn alloy ingot did not obtain anysignificant cracking when compared to others. XRD results reveal that ε phase and σ phase consist in all Co-35Cr-5Mo-xMn (x=0-1 weight %) alloys. Metallography examinations show precipitations of σ phase alongaustenite grain boundaries and striations in the interior of austenite grains. Striations are to be expected as εphase or deformation twinning. From this research study concludes that Co-35Cr-5Mo-0.4Mn is suitable forforging process. The existence of striation and σ phase lead to the low grade of forging ability in these alloys.Keywords : Co-35Cr-5Mo-xMn (x=0-1weight %) alloy, Implant material, Various addition of Mn, Forgingability, Striation, γ phase (fcc), σ phase, ε phase (hcp)
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Sari, Nasmi Herlina, Lalu Tumbuh Prasetya, and Agus Dwi Catur. "Baja AISI 1006: Efek Suhu Pemanasan Terhadap Sifat Mekanik Dan Strukturmikro." Jurnal METTEK 4, no. 1 (2018): 1. http://dx.doi.org/10.24843/mettek.2018.v04.i01.p01.
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Penyelidikan sifat–sifat dari baja AISI 1006 menggunakan suhu pemanasan masih sangat menarik untuk dikembangkan. Penelitian ini bertujuan untuk menyelidiki efek suhu pemanasan dan tempering terhadap sifat mekanik dan struktur mikro baja AISI 1006. Variasi suhu pemanasan yang digunakan adalah 850oC, 900oC dan 950oC. Proses tempering dilakukan pada suhu 200oC. Spesimen dibentuk mengikuti standar internasional untuk pengujian impak, kekerasan dan struktur mikro. Energi serap dan kekuatan impak ditentukan dengan menggunakan mesin uji impak, dan kekerasan baja diukur mengunakan mesin uji kekerasan Vickers. Selain itu, strukturmikro dari baja juga telah dianalisa menggunakan mikroskop metalografi. Hasil ini menunjukkan bahwa peningkatan suhu pemanasan dan tempering pada 200°C menurunkan nilai kekuatan impak dan penyerapan energi baja; sebaliknya, kekerasan baja meningkat; karena fase austenit berubah menjadi perlit dan sementit. Energi penyerapan dan kekuatan impak tertinggi diperoleh dari spesimen SRA. Sementara itu, nilai kekerasan tertinggi diperoleh dari spesimen TKC. Hasil ini diharapkan dapat memberikan data dan informasi bagi para peneliti dan industrialis dalam mengembangkan produk baja untuk berbagai aplikasi.
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Isworo, Hajar, and Najib Rahman. "EFFECT OF VARIATIONS IN HEATING TEMPERATURE AND COOLING MEDIA ON THE HARDNESS AND MICROSTRUCTURE OF STEEL ST 41 HARDENING METHOD." Scientific Journal of Mechanical Engineering Kinematika 5, no. 1 (2020): 37–50. http://dx.doi.org/10.20527/sjmekinematika.v5i1.136.
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Baja ST 41 merupakan salah satu dari jenis baja golongan baja karbon rendah dan dapat ditingkatkan lagi sifat mekaniknya dengan cara proses perlakuan panas. Hardening merupakan proses perlakuan panas yang bertujuan untuk meningkatkan kekerasan serta kekuatan baja dengan cara pemanasan, penahanan dan pendinginan dalam interval waktu dan media pendingin tertentu. Tujuan penelitian ini adalah untuk mengetahui pengaruh temperatur pemanasan dan media pendingin terhadap kekerasan dan struktur mikro baja ST 41. Proses hardening dilakukan pada temperatur austenit (850oC, 900oC dan 950oC) dengan waktu tahan (holding time) 15 menit kemudian didinginkan cepat menggunakan media pendingin aquades, oli SAE 20W-50, dan air kelapa. Hasil pengujian menunjukkan nilai kekerasan optimum adalah 326,2 HV pada temperatur pemanasan 850oC dengan media pendingin air dan kekerasan minimum 153,1 HV pada temperatur pemanasan 950oC dengan media pendingin oli SAE 20W-50, sementara hasil pengujian struktur mikro setelah proses hardening memperlihatkan struktur yang terbentuk adalah martensit dan bainit. Daripenelitian ini dapat diambil kesimpulan bahwa proses hardening dapat menaikkan nilai kekerasan pada baja ST 41.
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Hastuti, Kurnia, Esah Hamzah, and Jasmi Hashim. "PENGARUH TEMPERATUR AGING TERHADAP TEMPERATUR TRANSFORMASI PADUAN Ti-50.7at.%Ni SHAPE MEMORY." Jurnal Konversi Energi dan Manufaktur 3, no. 1 (2016): 35–40. http://dx.doi.org/10.21009/jkem.3.1.6.
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Tujuan penelitian ini adalah untuk mengetahui pengaruh temperatur aging terhadap temperatur transformasi paduan Ti-50.7at%Ni. Temperatur transformasi menjadi sangat penting pada material paduan shape memory karena sifat superelastisdan shape memory hanya akan dihasilkan pada temperatur tertentu sehingga membatasi penggunaan material ini. Padapenelitian ini, material diberi perlakuan panas dengan cara solution treatment pada 900oC selama satu jam diikuti denganpendinginan dalam air. Selanjutnya aging pada empat temperature yang berbeda yaitu 300oC, 400oC, 500oC dan 600oC.Temperature transformasi diamati dengan menggunakan Differential Scanning Calorimetry (DSC). Hasil penelitianmenunjukkan kehadiran B19′ martensit dalam struktur mikro material as-received tidak dapat dijelaskan dengan hasil grafikDSC. Hal ini dimungkinkan karena masih adanya pengaruh rolling dingin pada saat proses pembuatan plat yangmenyisakan kehadiran dislokasi di dalam material. Dislokasi ini menyebabkan martensit hadir pada temperature yang lebihtinggi dari seharusnya. Aging pada temperature yang bervariasi yaitu 300oC, 400oC, 500oC dan 600oC menyebabkantransformasi fasa dalam material Ti-50.7at.%Ni terjadi dalam dua tahap, yaitu B2 austenit bertransformasi menjadi fasaintermediate R, selanjutnya fasa ini akan bertransformasi menjadi B19′ martensit.
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Pinedo, Carlos Eduardo, and André Paulo Tschiptschin. "Low temperature plasma carburizing of AISI 316L austenitic stainless steel and AISI F51 duplex stainless steel." Rem: Revista Escola de Minas 66, no. 2 (2013): 209–14. http://dx.doi.org/10.1590/s0370-44672013000200011.
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In this work an austenitic AISI 316L and a duplex AISI F51 (EN 1.4462) stainless steel were DC-Plasma carburized at 480ºC, using CH4 as carbon carrier gas. For the austenitic AISI 316L stainless steel, low temperature plasma carburizing induced a strong carbon supersaturation in the austenitic lattice and the formation of carbon expanded austenite (γC) without any precipitation of carbides. The hardness of the carburized AISI 316L steel reached a maximum of 1000 HV due to ∼13 at% carbon supersaturation and expansion of the FCC lattice. For the duplex stainless steel AISI F51, the austenitic grains transformed to carbon expanded austenite (γC), the ferritic grains transformed to carbon expanded ferrite (αC) and M23C6 type carbides precipitated in the nitrided case. Hardness of the carburized case of the F51 duplex steel reached 1600 HV due to the combined effects of austenite and ferrite lattice expansion with a fine and dispersed precipitation of M23C6 carbides.
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Suarsana, I. Ketut, IGN Nitya Santhiarsa, and DNK Putra Negara. "Pengaruh Perlakuan Temperatur dan Media Pendinginan Terhadap Sifat Ketangguhan Baja AISI 3215." Jurnal METTEK 4, no. 1 (2018): 23. http://dx.doi.org/10.24843/mettek.2018.v04.i01.p04.
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Perlakuan panas adalah pemanasan yang diikuti dengan penahanan dan pendinginan menggunakan media quenching. Pengerasan adalah pemanasan logam hingga suhu austenit, tahan pada suhu tersebut untuk sementara waktu dan kemudian didinginkan pada media pendinginan seperti air, minyak, udara, air garam. Untuk mengatasi perubahan sifat mekanik, perlu diberikan proses perlakuan panas. Hal ini perlu dilakukan untuk menghilangkan stress internal dan mencegah terjadinya retak atau cacat. Sifat mekanis ketangguhan adalah kemampuan material untuk menyerap energi sesaat sebelum terjadi fraktur pada struktur itu. Penelitian ini membahas tentang prediksi ketangguhan properti mekanik dengan memberikan pemanasan pada temperatur 800, 850 dan 9000C dan masing-masing specimen diquenching dengan : air tawar, air laut dan minyak. Hasil penelitian menunjukkan bahwa terjadi peningkatan sifat ketangguhan dari efek temperatur dan media pendinginan yang digunakan. Data menunjukan pada 8000C dengan media quenching minyak nilai ketangguhan adalah 33,833 kg/cm2, serta suhu 9000C dengan quenching media air nilai ketangguhan adalah 40,8747 kg/cm2). Jadi semakin meningkat temperature perlakuan, berpengaruh terhadap sifat ketangguhan impak bahan.
Heat treatment is carried out by heating followed by anchoring and using quenching medium as cooling. Hardening is metal heating to austenite temperature, hold it at a temporary temperature and then cooled to cooling media such as water, oil, air, brine. To overcome the change of mechanical properties, need to be given process of heat treatment. This is to remove internal stress and prevent the occurrence of cracks or defects. The mechanical properties of toughness are the ability of the material to absorb energy without fracturing the structure. This study discusses the prediction of toughness of mechanical properties by heating at temperatures of 800, 850 and 9000C and each specimen quenching with: freshwater, seawater and oil. The results showed that there was an increase in the toughness properties of the temperature effect and the cooling medium used. The data show on 8000C with medium quenching oil the toughness value is 33.833 kg/cm2, and the temperature of 9000C with quenching medium water toughness value is 40.8747 kg/cm2). So the increasing of treatment temperature has influence to the material toughness
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Herizen, Dwi, and Rudi Siswanto. "PENGARUH VARIASI HOLDING TIME DAN MEDIA PENDINGIN TERHADAP KEKERASAN DAN STRUKTUR MIKRO BAJA SUS 630 METODE HARDENING." JTAM ROTARY 2, no. 2 (2020): 149. http://dx.doi.org/10.20527/jtam_rotary.v2i2.2411.
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SUS 630 memiliki kekerasan 30,9 HRC dan kandungan Chromium 12% berdasarkan pemakaiannya di PT. Pupuk Kalimantan Timur merekomendasikan kekerasan sebesar 55 HRC, untuk meningkatkan kekerasan material dapat dilakukan dengan teknik material engineering yaitu Hardening. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh variasi waktu tahan dan media pendingin terhadap kekerasan dan mikrostruktur baja sus 630. Proses pengerasan dilakukan hingga mencapai suhu 1020 0C kemudian waktu tahan dengan variasi 10, 20, 30, 40, dan 50 menit kemudian dicelupkan ke dalam air, air garam, dan minyak sampai suhu kamar. Struktur mikro diuji menggunakan mikroskop optik dengan perbesaran 400x dan kekerasan menggunakan kekerasan Rockwell C dengan beban 150 kg. Pengamatan struktur mikro setelah pengerasan struktur yang terbentuk adalah bilah martenstie, sisa austenit, dan karbida logam. Hasil uji kekerasan tertinggi pada media pendingin air (34,2 HRC), air asin (34,2 HRC), dan minyak (34,1 HRC) dan bahan baku (30,9 HRC). Dari penelitian ini dapat disimpulkan bahwa proses pengerasan dapat meningkatkan nilai kekerasan. SUS 630 Steel hardness is 30.9 HRC and Chromium content is 12%, based on its use at PT. Pupuk Kalimantan Timur recommended a hardness of 55 HRC, to increase material hardness can be done by means of material engineering, namely Hardening. The aim of the study was to determine the effect of variations in holding time and cooling media on the hardness and microstructure of steel sus 630. The hardening process was carried out to reach 1020 0C then holding time with variations of 10, 20, 30, 40, and 50 minutes then dipped into water , salt water, and oil to room temperature. Microstructure was tested using an optical microscope with 400x magnification and hardness using Rockwell C hardness with a load of 150 kg. The observation of the microstructure after hardening of the structure formed is the martenstie lath, residual austenite, and metal carbide. The hardness test results were highest in water cooling media (34.2 HRC), salt water (34.2 HRC), and oil (34.1 HRC) and raw material (30.9 HRC). From this study it can be concluded that the hardening process can increase the value of violence.
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Vohra, Rakesh V. "Mathematical and Quantitative Methods: Jane Austen, Game Theorist." Journal of Economic Literature 51, no. 4 (2013): 1187–90. http://dx.doi.org/10.1257/jel.51.4.1183.r3.
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Rakesh V. Vohra of University of Pennsylvania reviews, “Jane Austen, Game Theorist” by Michael Suk-Young Chwe. The Econlit abstract of this book begins: “Explores the ways in which the core ideas of game theory appear in Jane Austen's novels. Discusses the argument; game theory in context; folk tales and human rights; game theory in Flossie and the Fox; Austen's six novels; Austen's foundations of game theory; Austen's competing models; Austen on what strategic thinking is not; Austen's innovations; Austen on strategic thinking's disadvantages; Austen's intentions; Austen on cluelessness; and real-world cluelessness. Chwe is Associate Professor of Political Science at the University of California, Los Angeles.”
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Ravi Kumar, B., J. K. Sahu, and S. K. Das. "Influence of Annealing Process on Recrystallisation Behaviour of a Heavily Cold Rolled AISI 304L Stainless Steel on Ultrafine Grain Formation." Materials Science Forum 715-716 (April 2012): 334–39. http://dx.doi.org/10.4028/www.scientific.net/msf.715-716.334.
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AISI 304L austenitic stainless steel was cold rolled to 90% with and no inter-pass cooling to produced 89% and 43% of deformation induced martensite respectively. The cold rolled specimens were annealed by isothermal and cyclic thermal process. The microstructures of the cold rolled and annealed specimens were studied by the electron microscope. The observed microstructural changes were correlated with the reversion mechanism of martensite to austenite and strain heterogeneity of the microstructure. The results indicated possibility of ultrafine austenite grain formation by cyclic thermal process for austenitic stainless steels those do not readily undergo deformation induced martensite. Keywords: Austenitic stainless steel, Grain refinement, Cyclic thermal process, Ultrafine grain
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Suprihanto, Agus. "EVALUASI PERLAKUAN NITRIDASI GAS TEMPERATUR TINGGI TERHADAP STRUKTUR MIKRO, KEKERASAN DAN KETAHANAN AUS BAJA TAHAN KARAT AUSTENIT 316LVM." ROTOR 10, no. 1 (2017): 57. http://dx.doi.org/10.19184/rotor.v10i1.5149.
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High temperature gas nitriding for austenitic stainless steel 316LVM is successfully done. Specimens are treated at temperature 1323, 1373 and 1573 K for 15 minutes holding time at 0.3 atm nitrogen gas pressures. The effect of nitriding treatments on the hardness, wear resistance and microstructure are evaluated using Buehler microhardness tester, Ogoshi universal wear test machine and light optical microscop respectively. The results shows that hardness, wear resistance and grain size increase with treatments temperature.
Keywords: high temperature gas nitriding, 316LVM, hardness, wear, grain size
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Pernach, Monika, Krzysztof Bzowski, Roman Kuziak, and Maciej Pietrzyk. "Experimental Validation of the Carbon Diffusion Model for Transformation of Ferritic-Pearlitic Microstructure into Austenite during Continuous Annealing of Dual Phase Steels." Materials Science Forum 762 (July 2013): 699–704. http://dx.doi.org/10.4028/www.scientific.net/msf.762.699.
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Modeling of the transformation of the starting ferritic-pearlitic microstructure into austenite during heating in continuous annealing process was the objective of the work. Kinetics of this transformation was predicted by solving Avrami equation as well as carbon diffusion equation with a moving boundary. Mathematical and numerical models describing austenitic phase transformation were created for the 1D and 2D domains. Developed models were solved using the Finite Difference, as well as the Finite Element Method. Results of the numerical simulations include austenite volume fraction and carbon segregation profiles in the austenite. The former were compared with the experimental data obtained in laboratory simulations of the continuous annealing. Developed and validated model was applied to simulation of the austenitic transformation during annealing of DP steels.
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Harwarth, Michael, Adam Brauer, Qiuliang Huang, Mehdi Pourabdoli, and Javad Mola. "Influence of Carbon on the Microstructure Evolution and Hardness of Fe–13Cr–xC (x = 0–0.7 wt.%) Stainless Steel." Materials 14, no. 17 (2021): 5063. http://dx.doi.org/10.3390/ma14175063.
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The influence of carbon on the phase transformation behavior of stainless steels with the base chemical composition Fe–13Cr (wt.%), and carbon concentrations in the range of 0–0.7 wt.%, was studied at temperatures between −196 °C and liquidus temperature. Based on differential scanning calorimetry (DSC) measurements, the solidification mode changed from ferritic to ferritic–austenitic as the carbon concentration increased. The DSC results were in fair agreement with the thermodynamic equilibrium calculation results. In contrast to alloys containing nearly 0% C and 0.1% C, alloys containing 0.2–0.7% C exhibited a fully austenitic phase stability range without delta ferrite at high temperatures. Quenching to room temperature (RT) after heat treatment in the austenite range resulted in the partial transformation to martensite. Due to the decrease in the martensite start temperature, the fraction of retained austenite increased with the carbon concentration. The austenite fraction was reduced by cooling to −196 °C. The variation in hardness with carbon concentration for as-quenched steels with martensitic–austenitic microstructures indicated a maximum at intermediate carbon concentrations. Given the steady increase in the tetragonality of martensite at higher carbon concentrations, as confirmed by X-ray diffraction measurements, the variation in hardness with carbon concentration is governed by the amount and stability of austenite.
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Boemke, Annika, Marek Smaga, and Tilmann Beck. "Influence of surface morphology on the very high cycle fatigue behavior of metastable and stable austenitic Cr-Ni steels." MATEC Web of Conferences 165 (2018): 20008. http://dx.doi.org/10.1051/matecconf/201816520008.
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The present study investigates conventional and cryogenically turned specimens of metastable austenitic steel AISI 347 and stable austenitic steel AISI 904L in the VHCF regime. The cryogenic turning process includes cooling by CO2 snow and generates a surface layer on the specimens of metastable austenitic steel, which is characterized by a phase transformation from paramagnetic fcc - austenite to ferromagnetic bcc - martensite and grain refinement. The stable austenitic steel retains its purely austenitic structure after cryogenic turning, but also shows grain refinement in the surface layer. The specimens with different surface morphology were cyclically loaded at ambient temperature using an ultrasonic fatigue testing system developed and built at the authors’ institute. The testing machine operates at frequencies of approx. 20 kHz to achieve high numbers of load cycles within a reasonable time. To avoid self heating of the specimen, the tests were performed in pulse-pause mode. All specimens were tested with a load ratio of R = -1. During cyclic loading, the metastable austenitic steel partially transformed from paramagnetic fcc - austenite to ferromagnetic bcc - martensite, while no phase transformation could be detected in the stable austenitic steel.
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Reis, Adriano Gonçalves, Danieli Aparecida Pereira Reis, Antônio Jorge Abdalla, Antônio Augusto Couto, and Jorge Otubo. "An In Situ High-Temperature X-Ray Diffraction Study of Phase Transformations in Maraging 300 Steel." Defect and Diffusion Forum 371 (February 2017): 73–77. http://dx.doi.org/10.4028/www.scientific.net/ddf.371.73.
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An in situ high-temperature X-ray diffraction (HTXRD) study in maraging 300 steel was carried out to study the martensite to austenite transformation and effect of time of exposure in the austenite reversion below austenite start temperature. Solution annealed materials were subjected to controlled heating-holding cycles. The first sample was heated at a rate of 10 oC/min from room temperature to 800 oC, showing that the microstructure is completely martensitic (α’110) until 600 oC. From 650 oC until 800 oC, the microstructure is gradually changing from martensitic to austenitic, showed by the increasing peaks of γ111 and reducing peaks of α’110. At 800 oC the microstructure is completely austenitic (γ111). Another sample was heated at 10 oC/min from room temperature to 600 oC and held for 4 hours. At 600 oC, at 0 h time of exposure, only a martensitic peak was observed. An austenite peak can be observed after some time of exposure at this temperature. The volume fraction of austenite increased with increasing time of exposure at 600 oC, reaching 50/50 volume fraction after 4 hours of exposure. XRD diffraction patterns for the same sample that was held for 4 hours at 600 oC and then cooled down in air to room temperature showed the same intensity of austenite and martensitic peaks found in situ at 600 oC for 4 hours (retained austenite), with the volume fraction of 50/50 of austenite and martensite phases. The HTXRD technique can be used to identify and quantify martensite to austenite transformation and austenite retention.
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Kang, Jun-Yun, Jaecheol Yun, Byunghwan Kim, et al. "Micro-Texture Analyses of a Cold-Work Tool Steel for Additive Manufacturing." Materials 13, no. 3 (2020): 788. http://dx.doi.org/10.3390/ma13030788.
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Small objects of an alloy tool steel were built by selective laser melting at different scan speeds, and their microstructures were analyzed using electron backscatter diffraction (EBSD). To present an explicit correlation with the local thermal cycles in the objects, prior austenite grains were reconstructed using the EBSD mapping data. Extensive growth of austenitic grains after solidification could be detected by the disagreement between the networks of carbides and austenite grain boundaries. A rapid laser scan at 2000 mm/s led to less growth, but retained a larger amount of austenite than a slow one at 50 mm/s. The rapid scan also exhibited definite evolution of Goss-type textures in austenite, which could be attributed to the growth of austenitic grains under a steep temperature gradient. The local variations in the microstructures and the textures enabled us to speculate the locally different thermal cycles determined by the different process conditions, that is, scan speeds.
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Ryś, J., and A. Zielińska-Lipiec. "Deformation of Ferrite-Austenite Banded Structure in Cold-Rolled Duplex Steel / Odkształcenie Pasmowej Struktury Ferrytu I Austenitu W Walcowanej Na Zimno Stali Duplex." Archives of Metallurgy and Materials 57, no. 4 (2012): 1041–53. http://dx.doi.org/10.2478/v10172-012-0116-2.
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Duplex type ferritic-austenitic stainless steels develop a specific two-phase banded structure upon thermo-mechanical pre-treatment and subsequent cold-rolling. The band-like morphology of ferrite and austenite imposes different conditions on plastic deformation of both constituent phases in comparison to one-phase ferritic and austenitic steels. In the present research the ingot of a model ferritic-austenitic steel of duplex type, produced by laboratory melt, was subjected to preliminary thermo-mechanical treatment including forging and solution annealing. Afterwards cold-rolling was conducted over a wide deformation range. The investigations comprised examination of ferrite and austenite microstructures by means of optical and transmission electron microscopy and texture measurements after selected rolling reductions. The presented results indicate that deformation mechanisms operating within the bands of both constituent phases are essentially the same as compared to one-phase steels, however their appearance and contribution are changed upon deformation of two-phase banded structure. Different deformation behavior within ferrite-austenite bands in duplex steels, visible especially at higher strains, considerably affects microstructure evolution and in consequence texture formation in both phases.
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Kubler, R., M. Berveiller, M. Cherkaoui, and K. Inal. "Transformation Textures in Unstable Austenitic Steel." Journal of Engineering Materials and Technology 125, no. 1 (2002): 12–17. http://dx.doi.org/10.1115/1.1525249.
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During the martensitic transformation in elastic-plastic materials, the local transformation strain as well as the plastic flow inside austenite are strongly related with the crystallographic orientation of the austenitic lattice. Two mechanisms involved in these materials, i.e., plasticity by dislocation motion and martensitic phase formation are coupled through kinematical constraints so that the lattice spin of the austenitic grains is different from the one due to classical slip. In this work, the lattice spin ω˙eA of the austenitic grains is related with the slip rate on the slip systems of the two phases, γ˙A and γ˙M, the evolution of the martensite volume fraction f˙ and the overall rotation rate Ω˙ of the grains. This new relation is integrated in a micromechanical model developed for unstable austenite in order to predict the evolution of the austenite texture during TRansformation Induced Plasticity (TRIP). Results for the evolution of the lattice orientation during martensitic transformation are compared with experimental data obtained by X-ray diffraction on a 304 AISI steel.
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Antoine, P., B. Soenen, and Nuri Akdut. "Static Strain Aging in Cold Rolled Metastable Austenitic Stainless Steels." Materials Science Forum 539-543 (March 2007): 4891–96. http://dx.doi.org/10.4028/www.scientific.net/msf.539-543.4891.
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Transformation of austenite to martensite during cold rolling operations is widely used to strengthen metastable austenitic stainless steel grades. Static strain aging (SSA) phenomena at low temperature, typically between 200°C and 400°C, can be used for additional increase in yield strength due to the presence of α’-martensite in the cold rolled metastable austenitic stainless steels. Indeed, SSA in austenitic stainless steel affects mainly in α’-martensite. The SSA response of three industrial stainless steel grades was investigated in order to understand the aspects of the aging phenomena at low temperature in metastable austenitic stainless steels. In this study, the optimization of, both, deformation and time-temperature parameters of the static aging treatment permitted an increase in yield strength up to 300 MPa while maintaining an acceptable total elongation in a commercial 301LN steel grade. Deformed metastable austenitic steels containing the “body-centered” α’-martensite are strengthened by the diffusion of interstitial solute atoms during aging at low temperature. Therefore, the carbon redistribution during aging at low temperature is explained in terms of the microstructural changes in austenite and martensite.
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Dũng, Nguyễn Hữu. "CHUYỂN BIẾN AUSFFERIT TRONG CÔNG NGHỆ CHẾ TẠO GANG CẦU TÔI ĐẲNG NHIỆT (ADI)". Vietnam Journal of Science and Technology 51, № 6 (2018): 789. http://dx.doi.org/10.15625/2525-2518/51/6/11647.
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Gang cầu truyền thống chỉ có thể đạt được các chỉ tiêu cơ tính như : độ bền kéo 700 - 750 MPa; độ giãn dài: 2 – 5 %. Để đạt được các cơ tính cao hơn, tất nhiên là độ tin cậy của sản phẩm cũng cao hơn, cần phải kiểm soát các thông số như: thành phần hóa học của hợp kim, chất lượng vật đúc, cấu trúc graphit và quá trình nhiệt luyện. Bài báo này giới thiệu một phương pháp chế tạo gang cầu tôi đẳng nhiệt (ADI). Cấu trúc gang cầu ADI bao gồm pherit hình kim và austenit dư còn gọi là tổ chức ausferit. Cấu trúc này thể hiện sự kết hợp tuyệt vời về cơ tính: độ bền kéo 1200 MPa; độ giãn dài 7 – 8 %. Bài báo cũng sử dụng kết quả đo độ giãn nở nhiệt khi chuyển biến để tính toán các hệ số n và k trong phương trình Johnson–Mehl–Avrami và qua đó xây dựng giản đồ chuyển biến- nhiệt độ-thời gian. Cửa sổ quá trình trong trường hợp này được xác định là: tôi đẳng nhiệt ở 380 oC trong thời gian 2 giờ.
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Kawasaki, Yoshiyasu, Yuki Toji, Yokota Takeshi, and Yoshimasa Funakawa. "Effects of Tensile Testing Temperature on Mechanical Properties and Deformation Behavior in Medium Mn Steels." Materials Science Forum 1016 (January 2021): 1823–29. http://dx.doi.org/10.4028/www.scientific.net/msf.1016.1823.
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In single-phase austenitic steels, the optimum deformation temperature in the tensile test to obtain high tensile strength-elongation balance (TS×El) and work hardening rate (dσ/dε) depends on control of the stability of austenite. In order to clarify the effects of the deformation temperature in complex phase steels containing austenite, in this study, the effects of the tensile testing temperature on mechanical properties and deformation behavior were investigated in detail using steel A and steel B with a chemical composition of 0.15C-0.5Si-5.0Mn (wt%). Steels A and B consisted of ferrite and retained austenite, but contained different volume fractions of retained austenite, namely, 29 % and 17 % as a result of annealing at 660 °C and 620 °C for 2 h, respectively. The stability of the retained austenite of steel B was higher than that of steel A. In steel A, TS×El and dσ/dε achieved their maximum values at 20 °C, decreased from 20 to 100 °C, and then remained almost unchanged at more than 150 °C. On the other hand, in steel B, TS×El and dσ/dε achieved their maximum values at -40 °C, decreased from -40 to 50 °C and remained almost unchanged at more than 100 °C. These results can be explained by the stability of retained austenite and the transformation rate from retained austenite to martensite. It should be noted that control of the stability of retained austenite and the transformation rate from retained austenite to martensite led to an adjustment of the optimum deformation temperature to achieve the high TS×El and dσ/dε in medium Mn steels, in the same manner as in single-phase austenitic steels.
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Gigović-Gekić, Almaida, Hasan Avdušinović, Amna Hodžić та Ermina Mandžuka. "Effect of Temperature and Time on Decomposition of δ-ferrite in Austenitic Stainless Steel". Materials and Geoenvironment 67, № 2 (2020): 65–71. http://dx.doi.org/10.2478/rmzmag-2020-0007.
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AbstractMicrostructure of austenitic stainless steel is primarily monophasic, i.e. austenitic. However, precipitation of the δ-ferrite in the austenite matrix is possible depending on the chemical composition of steel. δ-Ferrite is stable on room temperature but it transforms into σ-phase, carbides and austenite during heat treatment. In this work, the results of analysis of influence of temperature and time on decomposition of δ-ferrite are presented. Magnetic induction method, microstructure and hardness analyses were used for testing the degree of decomposition of the δ-ferrite. Analysis of results showed that increase in temperature and time increases the degree of decomposition of δ-ferrite.
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Zheng, Shen Bai, Shao Hui Pan, Hui Wen, and Xiaog Xiong Wang. "Effect of Austenite Transition under Pulsating Magnetism." Advanced Materials Research 634-638 (January 2013): 1704–7. http://dx.doi.org/10.4028/www.scientific.net/amr.634-638.1704.
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The austenite steel was radiated by the intermediate frequency pulsating magnetism, and the effects that pulsating magnetic on the austenite transition was studied. The result shows that the pulsating magnetism promotes the austenitic grain growth of low carbon steel. If the magnetic field intensity is increased, it could provide better performance of raw materials to cold rolling processing.
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Zheng, Shen Bai, Shi Jie Liu, Hong Bin Li, Bin Feng, and Xue Song Hui. "Microstructure and Properties under Alternating Magnetism after Hot Rolling." Advanced Materials Research 1004-1005 (August 2014): 1256–59. http://dx.doi.org/10.4028/www.scientific.net/amr.1004-1005.1256.
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The austenite steel after rolling was radiated by the alternating magnetism, and the effects that alternating magnetic on the austenite transition was studied. The result shows that the alternating magnetism promotes the austenitic grain growth of low carbon steel. If the magnetic field intensity is increased, it could provide better performance of raw materials to cold rolling processing.