ANALISIS TEKSTUR PADALASAN STAINLESS STEEL 201 DENGAN TEKNIK DIFRAKSI NEUTRON. Baja tahan karat jenis austenitik merupakan baja tahan karat yang banyak dipakai dalam industri, salah satunya adalah industri rumah tangga. Dalam penelitian ini dilakukan karakterisasi Stainless Steel (SS) 201 yang banyak dijual di pasaran. Sebelum dilakukan karakterisasi, plat SS 201 dipotong dengan ukuran 150 mm × 120 mm× 10 mm, kemudian dibuat lubang berbentuk alur pada kedua permukaan, sehingga alur berbentuk X Double V Groove (DVG), selanjutnya alur DVG dilas dengan sistem pengelasan multi pass menggunakan metode pengelasan Metal Inert Gas (MIG). Bahan yang sudah dilas kemudian dikarakterisasi dengan teknik difraksi neutron untuk mendapatkan pola difraksi dan pole figure pada daerah pusat lasan FusionZone (FZ), daerah terpengaruh panas Heat Affected Zone (HAZ) dan daerah logam dasar Base Metal Zone (BMZ). Selanjutnya pole figure dianalisis dengan perangkat lunak Beartex untukmenentukan arah orientasi dan kekuatan tekstur pada ketiga daerah tersebut. Dari penelitian ini dapat disimpulkan bahwa pada daerah pusat lasan butir kristalit terorientasi {110}<112> dengan tipe Brass dengan indeks tekstur sekitar 3,12 m.r.d (multiple random distribution) yang ditunjukkan pada pole figure 200. Untuk daerah HAZ, tekstur paling kuat terorientasi pada {110}<001> atau tipe Goss dengan indeks tekstur 4,8 m.r.d. Pada daerah logamdasar, tekstur secara dominan terorientasi kearah {010}<100> atau tipe Cube dengan indeks tekstur tidak terlalu kuat, sekitar 1,53 m.r.d. Pada daerah pusat lasan, bidang (110) sejajar dengan sumbu normal (ND), dengan arah kristalit sejajar dengan arah pengerolan (RD) [112]. Pada daerah HAZ bidang (110) tersebut mengarah ke arah sumbu pengerolan [001], dengan indeks tekstur 1,5 kali lebih kuat dibanding FZ. Hal ini menunjukkan bahwa bidang (110) yang semula terorientasi kearah [112] pada FZ berubah menjadi sekitar 35,26º ke arah [001] pada daerah HAZ. Untuk daerah logamdasar bidang (010)mengarah sejajar dengan arah normal (ND) dan teksturmengarah pada arah pengerolan (RD) [100].

Theoretically, the preheating temperature refers to the start martensite temperature (Ms), and the martensite transformation can be considered as the conservation of the invariant habit-plane in the lattice structure. The habit-plane is the interface plane between austenite and martensite as measured on a macroscopic scale. From the calculation, Ms = 252 °C. The martensite formation can be affected by temperature or stress treatment. In this experiment, temperature treatment was conducted. The sample was treated at 250 °C ± 10 °C. Before and after the pre-heat treatment, the sample was characterized using the neutron diffraction method. BATAN's Texture Diffractometer (DN2) with a neutron wavelength of 1.2799Å was used to characterize the sample. Analysis of the crystal structure showed that there are three phases before the preheating. The lattice parameters (a) obtained were as follows: for the -phase, a = 2.8501 ± 0.0004 Å; for the α'phase, a= b =2.517 ± 0.003 Å, and c= 3.581 ± 0.002 Å; for the -phase, a= 3.5884 ± 0.0004 Å, Rwp = 17.94%, and  = 1.33. After preheating, only the -phase appears with a = 3.5830 ± 0.0005 Å, Rwp = 26.03%, and  = 1.17. The orientation distribution function is modeled by the sample symmetrization model based on triclinic to orthorhombic sample symmetry. It shows that, before being preheated, the -phase has {100} <001> with texture index (F 2 ) between 0.701 m.r.d. to 3.650 m.r.d., the α-phase has a texture index between 0.923 m.r.d. to 1.768 m.r.d., and the '-phase has a texture index between 0.910 m.r.d. to 1.949 m.r.d. After being preheated, the -phase also has {100} <001> with a texture index between 0.846 m.r.d. to 3.706 m.r.d. It can be concluded, that because of the high preheating temperature, a phase change from martensite to austenite occurred that allowed the sample to be welded easily. After preheating, the -phase has the same cubic type orientation {100} <001>, and the texture index is nearly the same as that before preheating, with not martensite present. AbstrakPengaruh Suhu Pemanasan-Awal pada Struktur Kristal dan Tekstur Baja Tahan Karat Martensitik. Secara teoritis, suhu pemanasan awal mengacu pada suhu martensit awal (Ms), dan transformasi martensit dapat dianggap sebagai konservasi dari habit-plane invarian dalam struktur kisi. Habit-plane adalah bidang antarmuka antara austenit dan martensit yang diukur pada skala makroskopik. Dari perhitungan, Ms = 252 °C. Pembentukan martensit dapat dipengaruhi oleh suhu atau perlakuan tekanan. Dalam percobaan ini, perlakuan suhu dilakukan. Sampel diperlakukan pada 250 °C ± 10 °C. Sebelum dan sesudah perlakuan pemanasan-awal, sampel dikarakterisasi menggunakan metode difraksi neutron. Difraktometer Tekstur BATAN (DN2) dengan panjang gelombang neutron 1,2799 Å digunakan untuk mengkarakterisasi sampel. Analisis struktur kristal menunjukkan bahwa ada tiga fase sebelum pemanasan awal. Parameter kisi (a) yang diperoleh adalah sebagai berikut: untuk fasa-α, a = 2,8501 ± 0,0004 Å; untuk fasa-α', a = b = 2,517 ± 0,003 Å, dan c = ...

Ancient maps reveal that Dutch colonial have covered alun-alun as the Moslem city image like those in Jakarta, Surabaya, except in Semarang. Both Indonesian Moslem and colonial city experts cannot explain the phenomena. The alun-alun lama Semarang left its morphologic artifacts. Which layer of urban design should be conserved? To reveal the layer of the development, three-dimensional picture by freehand modeling based on visual historical approach method can be done as an early stage. The civilization era are in interaction, but tend to neglect the Moslem city image. Further research is needed using a computer drawing, to get a clearly image of Moslem city. Keywords: city’s civilization era; conservation; urban pattern; morphology modelling eISSN 2514-751X © 2018. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open-access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia. https://doi.org/10.21834/aje-bs.v3i8.278

A system for data acquisition and control software for the neutron radiography facility at Serpong has been developed. The software was developed to replace the previously existing control software which was no longer used due to problems on its computer hardware. Visual Basic running under Microsoft Windows operating system was used in developing the new software. In the hardware side, the film grabber and the motor driver were replaced. In the new system, the film grabber which was used to capture the image in the old system is replaced with a programmable CCD camera. The motor driver which was used to control the camera in two directions has been replaced with a four-direction motor driver. The software is capable of displaying the images in a real time mode and record the images in the hard disk of a personal computer. To obtain optimal image quality, the software processes the captured images by performing temperature adjustment, camera exposure time adjustment, and integration of the captured image in a certain frame numbers. The software is capable of taking a number of snapshots at a certain time interval. For neutron tomography purposes, the software takes the snapshots automatically at a sample position in line with the stepping movement of the rotating sample table. The snapshots were saved in a picture format and a numeric format for further processing. The software has been successfully tested for real time method and tomography reconstruction. The data captured by using this software has been verified using both commercial and in-house computed tomography software.