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Sample records for alloy-d-9

  1. Thermal creep properties of alloy D9 stainless steel and 316 stainless steel fuel clad tubes

    International Nuclear Information System (INIS)

    Latha, S.; Mathew, M.D.; Parameswaran, P.; Bhanu Sankara Rao, K.; Mannan, S.L.

    2008-01-01

    Uniaxial thermal creep rupture properties of 20% cold worked alloy D9 stainless steel (alloy D9 SS) fuel clad tubes for fast breeder reactors have been evaluated at 973 K in the stress range 125-250 MPa. The rupture lives were in the range 90-8100 h. The results are compared with the properties of 20% cold worked type 316 stainless steel (316 SS) clad tubes. Alloy D9 SS were found to have higher creep rupture strengths, lower creep rates and lower rupture ductility than 316 SS. The deformation and damage processes were related through Monkman Grant relationship and modified Monkman Grant relationship. The creep damage tolerance parameter indicates that creep fracture takes place by intergranular cavitation. Precipitation of titanium carbides in the matrix and chromium carbides on the grain boundaries, dislocation substructure and twins were observed in transmission electron microscopic investigations of alloy D9 SS. The improvement in strength is attributed to the precipitation of fine titanium carbides in the matrix which prevents the recovery and recrystallisation of the cold worked microstructure

  2. Experience in quality assurance of alloy D9 clad tubes for Prototype Fast Breeder Reactor

    International Nuclear Information System (INIS)

    Kapoor, K.; Prahlad, B.

    2012-01-01

    Stainless Steel Alloy D9 is the material for cladding in various sub-assemblies of Prototype Fast Breeder Reactor (PFBR). The fabrication, inspection, testing and supply of the clad tubes for the first core of PFBR is nearly completed. The paper also compares the specification requirements and the achieved results for some of the critical aspects which is arrived after completing supply against the first core requirement

  3. Modeling Microstructural Evolution During Dynamic Recrystallization of Alloy D9 Using Artificial Neural Network

    Science.gov (United States)

    Mandal, Sumantra; Sivaprasad, P. V.; Dube, R. K.

    2007-12-01

    An artificial neural network (ANN) model was developed to predict the microstructural evolution of a 15Cr-15Ni-2.2Mo-Ti modified austenitic stainless steel (Alloy D9) during dynamic recrystallization (DRX). The input parameters were strain, strain rate, and temperature whereas microstructural features namely, %DRX and average grain size were the output parameters. The ANN was trained with the database obtained from various industrial scale metal-forming operations like forge hammer, hydraulic press, and rolling carried out in the temperature range 1173-1473 K to various strain levels. The performance of the model was evaluated using a wide variety of statistical indices and the predictability of the model was found to be good. The combined influence of temperature and strain on microstructural features has been simulated employing the developed model. The results were found to be consistent with the relevant fundamental metallurgical phenomena.

  4. Thermal stability and thermal property characterisation of Fe–14.4Cr–15.4Ni–2.4Mo–2.36Mn–0.25Ti–1.02Si–0.042C–0.04P–0.005B (mass%) austenitic stainless steel (Alloy D9I)

    Energy Technology Data Exchange (ETDEWEB)

    Tripathy, Haraprasanna [Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Raju, S., E-mail: sraju@igcar.gov.in [Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Rai, Arun Kumar [Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Panneerselvam, G. [Chemistry Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Jayakumar, T. [Metallurgy and Materials Group, Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India)

    2013-02-15

    Highlights: ► High temperature enthalpy, specific heat, lattice thermal expansion of Alloy D9I determined. ► Melting and solidification studied by thermal analysis. ► Integrated modelling by Debye–Grüneisen quasiharmonic formalism. ► Comprehensive thermal property assessment for austenitic stainless steel. -- Abstract: High temperature measurements of enthalpy increment (ΔH{sub T}°) and lattice parameter have been carried out on Alloy D9I by means of drop calorimetry and high temperature X-ray diffraction techniques, respectively. In addition, the thermal stability during heating and cooling from the melting range has been investigated by differential scanning calorimetry. It is found that under near equilibrium cooling conditions (3 K min{sup −1}), Alloy D9I exhibits L → γ austenite → L + γ + δ ferrite → γ + δ → γ solidification mode. However, the phase fraction of δ ferrite and the temperature region of γ + δ two phase domain are found to be small. The on-cooling liquidus and solidus temperatures are found to be 1684 and 1631 ± 5 K, respectively. The latent heat of solidification is found to be in the range, 190–220 J g{sup −1}. The thermal analysis study has revealed that solution treated Alloy D9I exhibits an endothermic dissolution of Ti(C,N) particles at about 1323 ± 2 K, with an associated heat effect of 16–20 J g{sup −1}. The specific heat C{sub p} and coefficient of linear thermal expansion α{sub l} at 298.15 K are estimated to be 486 J kg{sup −1} K{sup −1} and 1.15 × 10{sup −5} K{sup −1}, respectively. The measured temperature dependencies of C{sub p} and α{sub l} for Alloy D9I are in good agreement with the general trend exhibited by many austenitic steels. Further, an empirical linear correlation has been found between the measured temperature dependent molar volume and molar enthalpy values. The measured thermal property data have been modelled through Debye–Grüneisen formalism to obtain an

  5. Materials development for fast reactor applications

    Energy Technology Data Exchange (ETDEWEB)

    Jayakumar, T.; Mathew, M.D.; Laha, K.; Sandhya, R., E-mail: san@igcar.gov.in

    2013-12-15

    Highlights: • A modified version of alloy D9 designated as IFAC-1 has been developed. • Oxide dispersion strengthened Grade 91 steel with good creep strength developed. • 0.14 wt% nitrogen in 316LN stainless steel leads to improved mechanical properties. • Type IV cracking resistant Grade 91 steel with boron addition developed. • Mechanical properties of SFR materials evaluated in sodium environment. -- Abstract: Materials play a crucial role in the economic competitiveness of electricity produced from fast reactors. It is necessary to increase the fuel burn-up and design life in order to realize this objective. The burnup is largely limited by the void swelling and creep resistance of the fuel cladding and wrapping materials. India's 500 MWe Prototype Fast Breeder Reactor (PFBR) is in advanced stage of construction. The major structural materials chosen for PFBR with MOX fuel are D9 austenitic stainless steel as fuel clad and wrapper material, 316LN austenitic stainless steel for reactor components and piping and modified 9Cr-1Mo steel for steam generator. In order to improve the burnup, titanium, phosphorous and silicon contents in alloy D9 have been optimized for decreased void swelling and increased creep strength and this has led to the development of a modified version of alloy D9 as IFAC-1. Ferritic steels are inherently resistant to void swelling. The disadvantage is their poor creep strength. Creep resistance of 9Cr-ferritic steel has been improved with the dispersion of nano-size yttria to develop oxide dispersion strengthened (ODS) steel clad tube with long-term creep strength, comparable to alloy D9 so as to achieve higher fuel burnup. Improved versions of 316LN stainless steel with nitrogen content of about 0.14 wt% having higher creep strength to increase the life of fast reactors and modified 9Cr-1Mo steel with reduced nitrogen content and controlled addition of boron to improve type IV cracking resistance for steam generator

  6. Effect of ageing on the microstructural stability of cold-worked titanium-modified 15Cr-15Ni-2.5Mo austenitic stainless steel

    International Nuclear Information System (INIS)

    Venkadesan, S.; Bhaduri, A.K.; Rodriguez, P.; Padmanabhan, K.A.

    1992-01-01

    A titanium-modified 15Cr-15Ni-2.5Mo austenitic stainless steel conforming to ASTM A 771 (UNS S 38660), commercially called Alloy D9, is being indigenously developed for application as material for the fuel clad and the hexagonal wrapper for fuel subassemblies of the Prototype Fast Breeder Reactor. As this material would be used in the cold-worked condition and would be subjected to prolonged exposure to elevated service temperatures, the effect of ageing on the microstructural stability was studied as a function of the amount of cold work. The material was given 2.5-30% prior cold work and then aged at temperatures in the range 923 to 1173 K for times ranging from 0.25 to 1000 h. Hardness measurements made before and after ageing were correlated with the Larson-Miller parameter to determine the highest stable prior cold-work level. Optical microscopy was used to study the microstructural changes. The influence of prolonged exposure for two and three years at the operating temperatures of clad and wrapper, on the elevated temperature tensile properties of a 20% prior cold-worked Alloy D9 was also studied through accelerated ageing treatments based on the present parametric approach. (orig.)

  7. Microstructural stability of austenitic stainless steels on exposure to irradiation and elevated temperatures

    International Nuclear Information System (INIS)

    Parameswaran, P.; Radhika, M.; Saroja, S.; Vijayalakshmi, M.; Nanda Gopal, M.

    2011-01-01

    Cold worked 316 stainless steels employed as core material in fast reactors on exposure to neutron irradiation to 40 dpa at ∼ 450 deg C have resulted in microstructural changes in terms of formation of voids and extensive precipitation of carbides, eta phase and nickel silicides. As a consequence there is degradation in the mechanical properties of the material, particularly ductility. In order to achieve higher burnup it is essential to find better materials, which would exhibit less void swelling and retain the microstructure over long radiation doses. Accordingly alloy D9 with appropriate modifications of Ni and Cr content with Ti additions has been developed. Further modification of alloy D9 with respect to minor alloying additions namely Si and P is being studied, in order to enhance the radiation resistance for extending the service life of components. The effectiveness of these elements can be achieved if and only if they are retained in solution over long time of exposure at high temperatures and irradiation. Therefore, the thermal stability of the newly developed improved D9 alloys, with a constant Ti:C ratio and different levels of Si and P has been studied with respect to microstructural evolution and its influence on the mechanical properties. Thermal aging behavior of the alloy with varying titanium contents at elevated temperatures was also studied in detail to identify the optimum alloying levels. The alloys in the 20% cold worked condition exhibit austenitic grains interspersed with bands of fine cold worked grains. On aging in the temperature range of 873-1073K for various durations upto two years the alloy showed the presence of different phases such as M 23 C 6 , intermetallics and TiC whose quantity varies with temperature. The hardness values showed a trend of an initial increase in all the alloys but at longer times the hardness either showed saturation or a decrease followed by saturation. The microstructural parameters like grain size and

  8. Development of materials and manufacturing technologies for Indian fast reactor programme

    International Nuclear Information System (INIS)

    Raj, Baldev; Jayakumar, T.; Bhaduri, A.K.; Mandal, Sumantra

    2010-01-01

    Fast Breeder Reactors (FBRs) are vital towards meeting security and sustainability of energy for the growing economy of India. The development of FBRs necessitates extensive research and development in domains of materials and manufacturing technologies in association with a wide spectrum of disciplines and their inter-twining to meet the challenging technology. The paper highlight the work and the approaches adopted for the successful deployment of materials, manufacturing and inspection technologies for the in-core and structural components of current and future Indian Fast Breeder Reactor Programme. Indigenous development of in-core materials viz. Titanium modified austenitic stainless steel (Alloy D9) and its variants, ferritic/martensitic oxide-dispersion strengthened (ODS) steels as well as structural materials viz. 316L(N) stainless steel and modified 9Cr-1Mo have been achieved through synergistic interactions between Indira Gandhi Centre for Atomic Research (IGCAR), education and research institutes and industries. Robust manufacturing technology has been established for forming and joining of various components of 500 MWe Prototype Fast Breeder Reactor (PFBR) through 'science-based technology' approach. To achieve the strict quality standards of formed parts in terms of geometrical tolerances, residual stresses and microstructural defects, FEM-based modelling and experimental validation was carried out for estimation of spring-back during forming of multiple curvature thick plantes. Optimization of grain boundary character distribution in Alloy D9 was carried out by adopting the grain boundary engineering approach to reduce radiation induced segregation. Extensive welding is involved in the fabrication of reactor vessels, piping, steam generators, fuel sub-assemblies etc. Activated Tungsten Inert Gas Welding process along with activated flux developed at IGCAR has been successfully used in fabrication of dummy fuel subassemblies (DFSA) required for testing

  9. Development of materials and manufacturing technologies for Indian fast reactor programme

    Energy Technology Data Exchange (ETDEWEB)

    Raj, Baldev; Jayakumar, T.; Bhaduri, A.K.; Mandal, Sumantra [Indira Gandhi Centre for Atomic Research, Kalpakkam (India)

    2010-07-01

    Fast Breeder Reactors (FBRs) are vital towards meeting security and sustainability of energy for the growing economy of India. The development of FBRs necessitates extensive research and development in domains of materials and manufacturing technologies in association with a wide spectrum of disciplines and their inter-twining to meet the challenging technology. The paper highlight the work and the approaches adopted for the successful deployment of materials, manufacturing and inspection technologies for the in-core and structural components of current and future Indian Fast Breeder Reactor Programme. Indigenous development of in-core materials viz. Titanium modified austenitic stainless steel (Alloy D9) and its variants, ferritic/martensitic oxide-dispersion strengthened (ODS) steels as well as structural materials viz. 316L(N) stainless steel and modified 9Cr-1Mo have been achieved through synergistic interactions between Indira Gandhi Centre for Atomic Research (IGCAR), education and research institutes and industries. Robust manufacturing technology has been established for forming and joining of various components of 500 MWe Prototype Fast Breeder Reactor (PFBR) through 'science-based technology' approach. To achieve the strict quality standards of formed parts in terms of geometrical tolerances, residual stresses and microstructural defects, FEM-based modelling and experimental validation was carried out for estimation of spring-back during forming of multiple curvature thick plantes. Optimization of grain boundary character distribution in Alloy D9 was carried out by adopting the grain boundary engineering approach to reduce radiation induced segregation. Extensive welding is involved in the fabrication of reactor vessels, piping, steam generators, fuel sub-assemblies etc. Activated Tungsten Inert Gas Welding process along with activated flux developed at IGCAR has been successfully used in fabrication of dummy fuel subassemblies (DFSA) required

  10. Alloy development for cladding and duct applications

    International Nuclear Information System (INIS)

    Straalsund, J.L.; Johnson, G.D.

    1981-01-01

    Three general classes of materials under development for cladding and ducts are listed. Solid solution strengthened, or austenitic, alloys are Type 316 stainless steel and D9. Precipitation hardened (also austenitic) alloys consist of D21, D66 and D68. These alloys are similar to such commercial alloys as M-813, Inconel 706, Inconel 718 and Nimonic PE-16. The third general class of alloys is composed of ferritic alloys, with current emphasis being placed on HT-9, a tempered martensitic alloy, and D67, a delta-ferritic steel. The program is comprised of three parallel paths. The current reference, or first generation alloy, is 20% cold worked Type 316 stainless steel. Second generation alloys for near-term applications include D9 and HT-9. Third generation materials consist of the precipitation strengthened steels and ferritic alloys, and are being considered for implementation at a later time than the first and second generation alloys. The development of second and third generation materials was initiated in 1974 with the selection of 35 alloys. This program has proceeded to today where there are six advanced alloys being evaluated. These alloys are the developmental alloys D9, D21, D57, D66 and D68, together with the commerical alloy, HT-9. The status of development of these alloys is summarized

  11. A comparative wear study of sputtered ZrN coatings on Si and titanium modified stainless steel substrates

    International Nuclear Information System (INIS)

    Singh, Akash; Kuppusami, P.; Thirumurugesan, R.; Mohandas, E.; Geetha, M.; Kamaraj, V.; Kumar, Niranjan

    2010-01-01

    In the present work wear behaviour of ZrN films grown by a pulsed direct current magnetron sputtering method is reported. The films were grown on silicon (100) and titanium modified stainless steel (alloy-D9) substrates by reactive sputtering in a mixture of argon and nitrogen gases. The structural parameters, preferred orientation and crystallite size as a function of substrate temperatures in the range 300-873 K were studied using X-Ray Diffraction. Deposition parameters have been found to influence the growth rate, crystalline structure and surface roughness, which affect the tribological behaviour of the films. A comparative wear study was performed on these substrates with steel and ceramic balls to evaluate the frictional properties of films. The best tribological performance was found for the sample grown with low flow rates of nitrogen (≤ 2 SCCM) at 873K. The coefficient of friction was found to be lower for the films deposited at higher temperature using steel and ceramic balls. This behaviour was correlated with microstructure and deformation behaviour of coatings. (author)

  12. Electron microscopy an indispensable tool for knowledge based design and development of nuclear materials

    International Nuclear Information System (INIS)

    Saibaba, Saroja

    2015-01-01

    Development of materials for core components such as clad and wrapper for the Indian sodium cooled fast reactors and the plasma facing components in the ITER program has been a continuous indigenous effort involving a close collaboration between the designer, materials researcher and industry. In recent times there has been an intensive effort to design and develop new radiation resistant and high temperature materials which include the advanced austenitic and ferritic steels. An elaborate TEM investigation of the 20% Cold Worked SS316 austenitic stainless steel wrapper exposed to different damage levels from the Fast Breeder Test Reactor at Kalpakkam provided an in depth understanding on the mechanism of evolution of radiation induced phase changes and voids. The identification of η and G phases with unique microchemistry at 40 and 83 dpa respectively and the consequent depletion of beneficial elements Ni and Si from the matrix, resulted in precipitate associated voids and a high degree of volumetric swelling. This knowledge provided the impetus to develop alloy D9 and its variants with higher Ni, Ti and optimum amounts of Si and P where precipitation of fine stable Ti carbides/carbonitrides and phosphides imparts superior strength while the matrix precipitate interfaces act as defect sinks to control void swelling

  13. Microstructural evolution and control in laser material processing

    International Nuclear Information System (INIS)

    Kaul, R.; Nath, A.K.

    2005-01-01

    Laser processing, because of its characteristic features, often gives rise to unique microstructure and properties not obtained with other conventional processes. We present various diverse laser processing case studies involving control of microstructure through judicious selection of processing parameters carried out with indigenously developed high power CO 2 lasers. The first study describes microstructural control during end plug laser welding of PFBR fuel pin, involving crack pone alloy D9 tube and type 316 M stainless steel (SS) plug, through preferential displacement of focused laser beam. Crater and associated cracks were eliminated by suitable laser power ramping. Another case study describes how low heat input characteristics of laser cladding process has been exploited for suppressing dilution in 'Colomony 6' deposits on austenitic SS. The results are in sharp contrast to extensive dilution noticed in Colmony 6 hard faced deposits made by GTAW. A novel laser surface melting (LSM) treatment for type 316 (N) SS weld metal has been developed to generate a sensitization-resistant microstructure which leads to enhanced resistance against intergranular corrosion (IGC). IGC resistance of laser treated surface has been found to be critically dependent on laser processing parameters. Experimental observations have been analyzed with thermal simulation. We have also studied the effect of laser beam spatial intensity profile on the microstructure in LSM. We have developed laser-assisted graded hard facing of austenitic SS substrate with Stellite 6 which, in contrast to direct deposition either by laser or GTAW, produced smooth transition in chemical composition and hardness used to control grain coarsening and martensite formation in type 430 SS weldment. Laser rapid manufacturing (LRM) is emerging as a new rapid and cost effective process for low volume fabrication, esp. of expensive materials. The talk will also present microstructural characteristics of laser