Effect Of -Quenching On Oxidation Resistance Of Zirconium Alloyzrnbmoge For Fuel Cladding Material

Effect of b-quenching of Zr-2.5Nb-0.5Mo-0.1Ge alloy used for advanced fuel cladding material of Pressurized Water Reactor (PWR) was investigated. The aim of this research isto improve the mechanical and corrosion properties through modificationof the alloy with regard to high reactor burn up. The quenching process was conducted by heating the sample at temperature of 950 oCand soaking 2.5 hours,followed by quenching in water at room temperature and then continued with annealing process at 500 and 600oC. The change of hardness and oxidation resistance were characterized using optical microscope and scanning electron microscope (SEM). The effect on the oxidation resistance was investigated by the high temperature oxidation test using the MSB (Magnetic Suspension Balance) at 700 oC for 5 hours. The hardness increased from 217 VHN to 265 VHN after quenching due to grain refinement and precipitation hardening. The oxidation rate followed the typical parabolic growth characteristic. The formation of thin layer was considered to be a stable oxide ZrO2that influenced the oxidation characteristic and increasing the hardness of the alloy

Non-destructive Residual Stress Analysis Around the Weld-Joint of Fuel Cladding Materials of ZrNbMoGe Alloys

The residual stress measurements around weld-joint of ZrNbMoGe alloy have been carried out by using X-ray diffraction technique in PTBIN-BATAN. The research was performed to investigate the structure of a cladding material with high temperature corrosion resistance and good weldability. The equivalent composition of the specimens (in %wt.) was 97.5%Zr1%Nb1%Mo½%Ge. Welding was carried out by using TIG (tungsten inert gas) technique that completed butt-joint with a current 20 amperes. Three region tests were taken in specimen while diffraction scanning, While diffraction scanning, tests were performed on three regions, i.e., the weldcore, the heat-affected zone (HAZ) and the base metal. The reference region was determined at the base metal to be compared with other regions of the specimen, in obtaining refinement structure parameters. Base metal, HAZ and weldcore were diffracted by X-ray, and lattice strain changes were calculated by using Rietveld analysis program. The results show that while the quantity of minor phases tend to increase in the direction from the base metal to the HAZ and to the weldcore, the quantity of the ZrGe phase in the HAZ is less than the quantity of the ZrMo2 phase due to tGe element evaporation. The residual stress behavior in the material shows that minor phases, i.e., Zr3Ge and ZrMo2, are more dominant than the Zr matrix. The Zr3Ge and ZrMo2 experienced sharp straining, while the Zr phase was weak-lined from HAZ to weldcore. The hydrostatic residual stress (σ) in around weld-joint of ZrNbMoGe alloy is compressive stress which has minimum value at about -2.73 GPa in weldcore region. Received: 16 January 2013; Revised: 25 April 2013; Accepted: 10 June 201

SINTESA DAN KARAKTERISASI PADUAN ZrNbMoGe UNTUK MATERIAL KELONGSONG BAHAN BAKAR NUKLIR

Sintesa paduan ZrNbMoGe untuk material kelongsong dilakukan dengan proses peleburan dan pengerolan panas untuk menghasilkan pelat tipis dengan ketebalan 1,4 mm. Proses peleburan dilakukan dengan melebur unsur pemadu ZrNbMoGe dalam dapur busur listrik dengan komposisi (prosen berat) 97,5% Zr, 1% Nb, 1% Mo dan 0,5% Ge. Proses pengerolan panas dilakukan pada temperatur 800 oC dan 850 oC dengan rasio reduksi 5 % untuk tiap langkah. Hasil karakterisasi menunjukkan kekerasan ingot dan pelat paduan ZrNbMoGe masing-masing sebesar 199 VHR dan 188 VHR, lebih tinggi dibandingkan kekerasan bahan kelongsong Zirkaloi-4. Peningkatan kekerasan diperkirakan terjadi akibat terbentuknya presipitat keras Zr3Ge dalam ingot selama proses peleburan, yang telah diamati dari hasil uji presipitat dengan SEM-EDX dan uji XRD. Hasil uji korosi dalam lingkungan air aqua bidistillate menunjukkan laju korosi yang cukup rendah sebesar 0,0457 MPY, sedangkan hasil uji oksidasi suhu tinggi pada temperatur 800 oC selama 36 jam memberikan pertambahan berat sebesar 0,0959 mg/cm2, mendekati harga pertambahan berat untuk bahan Zirkaloi-4 sebesar 0,1105 mg/cm2.Kata kunci : sintesa, zirkonium, kelongsong, rol.   Synthesis of ZrNbMoGe alloy used for nuclear fuel cladding material was performed by melting and hot rolling processes to produce thin plates of 1.4 mm thickness. The melting process was done by melting the elements of ZrNbMoGe alloy using an arc melting furnace with compositions (weight percentage) of 97.5% Zr, 1% Nb, 1% Mo and 0.5% Ge. The hot rolling process was done at temperatures of 800 oC and 850 oC with reduction ratios of 5% for each step. Result of the characterizations showed that the hardness of ingot and plate of ZrNbMoGe alloy were 199 VHR and 188 VHR respectively. These are higher than the hardness of the cladding material of Zircaloi-4. Increasing of hardness was believed due to the formation of hard precipitates of Zr3Ge in the ingot during the melting process which was observed by precipitate analysis using SEM-EDX and XRD tests. The corrosion tests in deminwater environment showed relatively low corrosion rate of 0.0457 MPY, while the high temperature oxidation test at 800 oC for 36 hours gave additional weight of 0.0959 mg/cm2, similar to that of zirkaloi-4 at 0.1105 mg/cm2. Keywords : synthesis, zirconium, cladding , roll

Pengaruh Implantasi Ion Argon pada Struktur Mikro dan Kekerasan Baja Aisi 430 untuk Bahan Struktur Reaktor

EFFECTSOF Ar-ION IMPLANTATION ON MICROSTRUCTURE AND HARDNESS OF AISI 430 STEEL FOR REACTOR STRUCTURE MATERIAL. Surface engineering by using implantation technique of argon (Ar+) ion may improve the performance ofmaterials especially the hardness. TheAISI 430 commercial steels were implanted by using argon ion to be utilized for reactor component materials applications. The change of microstructure and hardness after implantation was investigated to analyze the change ofmechanical properties. Ion implantation was carried out at acceleration energy of 100 keV and ion current of 10mA for 30, 60 and 90 minutes. Observation of the micro structure and phase were performed by an optical microscope showed the diffusion process of ion argon to the surface of commercial steel of AISI 430 , and the XRD (X-ray diffraction ), the hardness test was carried out by Vickers method. Results of the optical microscope test showed that the depth of argon diffusion was around 0.5 micron for 60 minutes and 2 micron for 90 minutes implantation. The test results showed XRD reflection peak identification field of (110), (200) and (211) successively appear at diffraction angles 2θ= 44,57o ; 64,86o ; and 82,11o . Ion implantation does not rise a new peak and phase which shows only a process of substitution and not interstitials of argon to the iron matrix at the BCC crystals lattice, because the radii of argon atom is 0,987 Å, a level with covalent radii of iron is1.17 Å, it is shown in diffraction angle shift. Hardness changes occur in the process according to the dose ion implantationArgon through the addition of implantation time.At the time of 30minutes implantation argon ion to the commercial steel AISI 430, the hardness is 190,78 HV, after 60 minutes implantation the hardness is 222,53 HV, and after 90minutes implantation argon ion to the commercial steel AISI 430, the hardness becomes 241,46 HV

KARAKTERISASI BAHAN PADUAN Al-Si HASIL PROSES SQUEEZE CASTING

KARAKTERISASI BAHAN PADUAN Al-Si HASIL PROSES SQUEEZE CASTING. Proses cor perah (squeeze casting) dilakukan untuk meningkatkan kualitas bahan paduan Al-Si yang banyak digunakan untuk komponen otomotif. Bahan paduan Al-Si dari suatu piston diambil sebagai sampel dan dilakukan daur ulang dengan proses cor perah dengan variasi tekanan 200 kgf/cm2, 300 kgf/cm2 dan 400 kgf/cm2. Karakteristik bahan sebelum proses dibandingkan dengan hasil karakterisasi bahan hasil perlakuan cor perah untuk evaluasi perubahan sifat mekanik dan strukturmikro. Karakterisasi bahan dilakukan dengan pengujian komposisi, uji kekerasan, porositas, strukturmikro dan uji struktur kristal. Hasil pengujian menunjukkan terjadinya kenaikan kekerasan akibat perlakuan cor perah dari 40 HRA sebelum proses menjadi 46 HRA setelah proses dengan tekanan 300 kgf/cm2. Kenaikan kekerasan disertai dengan penurunan porositas dari 5% menjadi 0,3% dengan perubahan butir dalam strukturmikro yang semakin halus. Hasil pengujian struktur kristal untuk sampel sebelum dan sesudah perlakuan cor perah menunjukkan struktur kristal kubus pusat bidang dan tidak terjadi perubahan fasa

SINTESA DAN KARAKTERISASI PADUAN ZrNbMoGe UNTUK MATERIAL KELONGSONG BAHAN BAKAR NUKLIR

Sintesa paduan ZrNbMoGe untuk material kelongsong dilakukan dengan proses peleburan dan pengerolan panas untuk menghasilkan pelat tipis dengan ketebalan 1,4 mm. Proses peleburan dilakukan dengan melebur unsur pemadu ZrNbMoGe dalam dapur busur listrik dengan komposisi (prosen berat) 97,5% Zr, 1% Nb, 1% Mo dan 0,5% Ge. Proses pengerolan panas dilakukan pada temperatur 800 oC dan 850 oC dengan rasio reduksi 5 % untuk tiap langkah. Hasil karakterisasi menunjukkan kekerasan ingot dan pelat paduan ZrNbMoGe masing-masing sebesar 199 VHR dan 188 VHR, lebih tinggi dibandingkan kekerasan bahan kelongsong Zirkaloi-4. Peningkatan kekerasan diperkirakan terjadi akibat terbentuknya presipitat keras Zr3Ge dalam ingot selama proses peleburan, yang telah diamati dari hasil uji presipitat dengan SEM-EDX dan uji XRD. Hasil uji korosi dalam lingkungan air aqua bidistillate menunjukkan laju korosi yang cukup rendah sebesar 0,0457 MPY, sedangkan hasil uji oksidasi suhu tinggi pada temperatur 800 oC selama 36 jam memberikan pertambahan berat sebesar 0,0959 mg/cm2, mendekati harga pertambahan berat untuk bahan Zirkaloi-4 sebesar 0,1105 mg/cm2.Kata kunci : sintesa, zirkonium, kelongsong, rol.   Synthesis of ZrNbMoGe alloy used for nuclear fuel cladding material was performed by melting and hot rolling processes to produce thin plates of 1.4 mm thickness. The melting process was done by melting the elements of ZrNbMoGe alloy using an arc melting furnace with compositions (weight percentage) of 97.5% Zr, 1% Nb, 1% Mo and 0.5% Ge. The hot rolling process was done at temperatures of 800 oC and 850 oC with reduction ratios of 5% for each step. Result of the characterizations showed that the hardness of ingot and plate of ZrNbMoGe alloy were 199 VHR and 188 VHR respectively. These are higher than the hardness of the cladding material of Zircaloi-4. Increasing of hardness was believed due to the formation of hard precipitates of Zr3Ge in the ingot during the melting process which was observed by precipitate analysis using SEM-EDX and XRD tests. The corrosion tests in deminwater environment showed relatively low corrosion rate of 0.0457 MPY, while the high temperature oxidation test at 800 oC for 36 hours gave additional weight of 0.0959 mg/cm2, similar to that of zirkaloi-4 at 0.1105 mg/cm2. Keywords : synthesis, zirconium, cladding , roll

Effect of Germanium to the Corrosion Resistance of Zr-nb-mo-ge Alloy for Nuclear Power Plant Fuel Cladding Material

Syntesis of the Zr-Nb-Mo-Ge alloy was performed to develop a nuclear fuel cladding material for Nuclear Power Plan (NPP). Additional of the Germanium (Ge) element can improve the hardness of the alloy caused by the formation of a hard precipitate of Zr-Ge. Test of the corrosion resistance in the environment of demin water and high temperature steam were necessarily performed to evaluate the alloy composition used as a cladding material. The corrosion resistance test in the demin water and high temperature steam environment was conducted to the sample of the alloy with composition of 0.5 %, 1 % and 2 % Ge. High temperature oxidation test was performed at 500 oC and 800 oC for 8 hours. The change of corrosion rate was analyzed based on the weight gain and the oxidation protective layer growth during oxidation test. The test results shows the corrosion rate in demin water environment of samples with 0,5%Ge, 1%Ge and 2%Ge were around 0.020, 0.048 and 0.0457MPY respectively. The weight gain produced in the oxidation test at 500 oC and 800 oC during 8 hours increased by increasing of the Ge content, the oxidation layer thickness of the samples were relatively same around 77 µm. It can be concluded from the experiment that the alloy containing of 0.5-2 %weight, have a good corrosion resistance used as a cladding material, while addition of the Ge element will decrease the the corrossion resistance of the Zr-Nb-Mo-Ge alloy

PENGARUH PROSES OKSIDASI PADA LOGAM PADUAN ZR-2,5NB UNTUK MATERIAL BIOIMPLAN

ABSTRAKPenelitian tentang pengaruh proses oksidasi pada logam paduan Zr-2,5Nb untuk material bioimplan telah dilakukan. Penelitian ini bertujuan untuk mengetahui stuktur mikro, kekerasan, ketahanan korosi dan toksisitas paduan logam Zr-2,5Nb sebelum dan sesudah dioksidasi. Pengujian stuktur mikro dengan mikroskop optik memperlihatkan paduan homogen berbentuk equiaxial. Proses oksidasi dilakukan menggunakan alat MSB selama 5 jam dengan variasi suhu 500ºC, 600ºC dan 700ºC. Pada oksidasi suhu 500°C tebal lapisan oksida  berkisar antara 4,06 – 5,02 µm, pada suhu 600°C tebal lapisan antara 4,20 – 7,80 µm danpada suhu 700°C tebal lapisan oksida 19,00 – 23,60 µm. Sebelum oksidasi kekerasan sebesar 233,7 VHN. Pada logam setelah dioksidasi 500°C kekerasan rata-rata sebesar 242,4 VHN. Pada oksidasi 600°C kekerasan sebesar 261,2 VHN dan 700°C kekerasan sebesar 399,1 VHN. Nilai laju korosi sebelum oksidasi sebesar 0,0695 mpy. Setelah proses oksidasi nilai korosi sampel jauh lebih rendah yaitu sebesar 0,0094 mpy. Persentasi inhibisi paduan sebelum oksidasi sebesar 13,3 % dan setelah oksidasi memiliki persentasi inhibisi sebesar 0 %, yang sangat baik  dimanfaatkan sebagai material bioimplan.Kata kunci : paduan zirkonium, oksidasi MSB, kekerasan, korosi, metode in vitro, bioimplanAbstractResearch on the effect of oxidation on the metal alloy Zr-2,5Nb for bioimplant material has been done. This research aims to find out the micro structure, hardness, corrosion resistance and toxicity of metal alloys Zr-2,5Nb before and after being oxidized. The micro structure tested by optical microscopy show a homogeneous alloy shaped equiaxial. The oxidation process is done using a MSB for 5 hours with temperature variations of 500ºC, 600ºC and 700ºC. Oxide layer thickness was measured by using SEM. At the oxidation temperature of 500°C the oxide layer thickness ranged from 4,06 to 5,02 µm, at a temperature of 600°C layer thickness between 4,20 and 7,80 µm and at temperature of 700°C the oxide layer thickness from 19,00 to 23,60 µm. Alloy hardness before oxidation  is 233,7 VHN, whereafter oxidized of 500 °C the average of metal hardness is 242,4 VHN. At 600°C oxidation the hardness is 261,2 VHN and 700°C is 399,1 VHN. Corrosion rate value before oxidation is 0,0695 mpy. After the oxidation process the corrosion rate value is much lower than before oxidation and equal to 0,0094 mpy. This is due to the presence of oxygen contained in the oxide layer. The percentage inhibition of oxidation of the alloy before oxidation is 13.3% and after oxidation is 0%, which is well used as material bioimplant.Keywords : zirconium alloys, oxidation MSB, hardness, corrosion, in vitro methods, bioimplan

Compatibility of a Zircaloy in Lead-bismuth Eutectic Heavyliquid Metal

Liquid Lead-Bismuth Eutectic (LBE) is a coolant of one of main candidates for the future nuclear reactor in the world (Generation IV reactors) i.e. LFR (Lead alloy-cooled Fast Reactor), and also a spallation target material for ADS (Accelerator Driven Transmutation System). The liquid has several advantages from neutronic, thermal-hydraulic, and inert characteristic with water and air. Nevertheless, the liquid LBE has the corrosive characteristic to metals as constituent materials of fuel cladding and structural of the reactors. Therefore, development of fuel cladding and structural materials in lead-bismuth eutectic environment is one of key issues for the deployment of LFR and ADS. A zirconium alloy material i.e. ZrNbMoGe has been developed in the Center for Technology of Nuclear IndustryMaterials (PTBIN)-BATAN. In order to explore the characteristics of the zircaloy, investigation of compatibility of ZrNbMoGe in liquid LBE has been done using COSTA apparatus facility at Pulsed Power and Microwave Technology, Karlsruhe Institute of Technology Germany. The test was done at 550 ºC of temperature with an oxygen concentration of 1x10-6 wt.% for 312 hours. The result showed the trace of zirconium oxide formation on the surface of the sample. This phenomenon revealed that in a relatively short time the zirconium alloy consumed a lot of oxygen in liquid LBE to form zirconium oxide on the surface of the sample. However, the zirconium oxide was spalled off from the surface of the sample because of fast formation with relatively thick of the zirconium oxide. Therefore, the zircaloy is not compatible with lead-bismuth eutectic heavy liquid metal that is used in the nuclear reactor system