R and D status of China low activation martensitic steel

International Nuclear Information System (INIS)

Huang Qunying; Li Chunjing; Li Yanfen; Liu Shaojun; Wu Yican; Li Jiangang; Shan Yiyin; Yu Jinnan; Zhu Shengyun; Zhang Pinyuan; Yang Jianfeng; Han Fusheng; Kong Mingguang; Li Heqin; Muroga, T.; Nagasaka, T.

2007-01-01

The Reduced Activation Ferritic/Martensitic (RAFM) steel is considered as the primary candidate structural material for DEMO and the first fusion plant, and widely studied in the world. China low activation martensitic steel (CLAM) is being developed in Institute of Plasma Physics, Chinese Academy of Sciences, under wide collaboration with many other domestic and foreign institutes and universities. This paper summarized the main R and D progress on CLAM, which covered composition optimization of the CLAM, smelting and processing techniques, physical and mechanical property test and evaluation before and after irradiation, compatibility with liquid LiPb, welding techniques etc. Finally, further research and development, and the prospects on its application were stated. (authors)

Influence of Nb content on grain size and mechanical properties of 18 wt% Cr ferritic stainless steel

Energy Technology Data Exchange (ETDEWEB)

Kang, Y. [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Mao, W.M., E-mail: weiminmao@263.net [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Chen, Y.J. [School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Jing, J.; Cheng, M. [Taizhou Xinyu Precision Manufacture Company Limited, Jiangyan 225500, Jiangsu (China)

2016-11-20

The influence of Nb contents between 0.20 and 1.20 wt% on the grain size and mechanical properties of 18 wt% Cr ferritic stainless steel produced by investment casting was investigated. The average grain sizes of the three steels decreased apparently with increasing Nb content mainly due to the increasing number of pre-existing oxides formed at higher temperature, which were more likely to be the nuclei of heterogeneous nucleation. The thermodynamic analysis of Nb(C,N) formation was in conformity to the experimental result that the Nb(C,N) precipitates became larger with increasing Nb content. The as-cast specimen with the smallest grain size of steel C had the worse tensile strength and elongation in comparison with the as-cast specimens of steels A and B, mostly owing to the catenarian and dendritic Nb(C,N) particles distributed densely at the grain boundaries. The mechanical properties of specimens were not improved remarkably through high temperature solid-solution, whereas the mechanical properties of normalized specimens in the three steels were improved to different degrees. The coalescence and sparse distribution of smaller precipitates at grain boundaries after normalizing effectively weakened the local stress concentration arising from the reticular distribution of particles. The normalized specimen of steel A with 0.24 wt% Nb still showed good mechanical properties. Normalizing at 850 °C for 2 h is the appropriate heat treatment for the 18 wt% Cr ferritic stainless steel. The comparatively rational Nb content of the ferritic stainless steel is between 0.20 and 0.40 wt% for investment casting production.

Ultrasound surface treatment of Kh18N10T steel with different structural state. Ul'trazvukovaya poverkhnostnaya obrabotka stali Kh18N10T s razlichnym strukturnym sostoyaniem

Energy Technology Data Exchange (ETDEWEB)

Aksenov, V K; Danilov, P A; Mats, A V; Netesov, V M; Yaes, A A [AN Ukrainskoj SSR, Kharkov (Ukrainian SSR). Fiziko-Tekhnicheskij Inst.

1989-09-01

Ultrasound surface treatment (USST) is studied for its effect on the structure and mechanical-and-physical properties of Kh18N10T steel with different prehistory. It is shown that surface treatment may both increase and decrease steel microhardness.

Effect of rolling temperature on 12Kh18N10T steel tube hardening

International Nuclear Information System (INIS)

Yushkevich, P.M.; Stepanovich, V.E.; Manankova, L.V.; Usenko, V.N.; Semenov, I.A.

1984-01-01

Mechanical properties and substructure of tubes at the constant reduction degree k(the ratio of deformation over wall thickness to deformation over diameter), depending on strain degree during cold and hot tube rolling, have been studied. The investigations are carried out using hot-rolled tubes with the dimensions 88x8 mm of 12Kh1hN10T steel. With the decrease of strain over the wall of the tube, produced of 12Kh18N10T steel as to strain over diameter the values of yield strength and ultimate strength increase with simultaneous decrease in ductility during warm rolling and yield strength and ultimate strength decrease with the increase in ductility-during cold rolling. During warm rolling of the tubes at 250 deg C the hardening of 12Kh18N10T steel is higher, than at the rolling temperature 150 deg C. The optimum temperature range of warm rolling is 120-150 deg C. Grain orientation in the metal of the tubes and degree of texture perfection increase with the temperature increase of the tube warm drolling as compared with col rolli

Influence of local microplastic strains on stress corrosion of 08Kh18N10T steel

International Nuclear Information System (INIS)

Moskvin, L.N.; Efimov, A.A.; Sherman, Ya.I.; Fedorova, T.I.

1987-01-01

Study on specific features of microhomogeneous strain in the process of plastic strain development and their role in stress corrosion of 08Kh18N10T steel sheet specimens subject to preliminary strain by 1, 3, 6, 16 and 23% and subsequent tests of stress corrosion in magnesium chloride solution at 150 deg C 140 MPa has been carried out. Analysis of test results has shown that microplastic strain is distributed over a specimen nonuniformly and is accompanied with the slip bands formation which are sources of corrosion crack origination and development. 08Kh18N10T steel manifests the highest trend to stress corrosion under 1% microplastic strain

R and D Developments. Research Programs on Irradiation Embrittlement of Reactor Vessel Steels

International Nuclear Information System (INIS)

Gomez Briceno, D.; Lapena, J.; Serrano, M.; Perosanz, F.

2000-01-01

Irradiation embrittlement of pressure vessel steels is a degradation mechanism time dependent that can lead to operational restrictions with adverse effects in the efficiency and life of a plant. For the last year, several research programs have been devoted to study thye evaluation of neutronic radiation effect on mechanical properties of pressure vessel steels. However, at the present, there is a growing interest on the development of new methodologies to optimize the surveillance program information, and the understanding of the irradiation damage mechanism. This paper give an overview of international research programs, and on the R+D activities carried out by the Structural Materials Project on irradiation embrittlement on pressure vessel steels. (Author)

Study of the decarburization of 18-8 stainless steel by oxygen at low pressure

International Nuclear Information System (INIS)

Armand, G.; Lapujoulade, J.

1964-01-01

The kinetic of the decarburization of a 18-8 stainless-steel by oxygen at low pressure has been studied between 1050 and 1200 C. The measurement of the carbon content of the sample is carried out by chemical analysis. Three mechanisms take place in that decarburization: diffusion of carbon in the steel; velocity at the superficial reaction C + 1/2 O 2 ↔ CO; pumping out of CO. The second mechanism seems to govern the overall kinetic. The activation energy of the phenomenon is 108 ± 24 Kcal/mole. (authors) [fr

Tribocorrosion behaviour of 08CH18N10T steel

International Nuclear Information System (INIS)

Kubecka, P.; Tvrdy, M.; Wenger, F.; Ponthiaux, P.

2000-01-01

Tribocorrosion of the 08CH18N10T austenitic stainless steel in a potassium sulphate solution was investigated with the help of pin-on-disk tribometer and polarisation curves method. The results indicate the occurrence of synergetic interactions between electrochemical and mechanical conditions: the damaging of the passive film by friction was pointed out, leading to an increase in the dissolution rate of the metal and simultaneously, the occurrence of electrochemical reactions (gas evolution, dissolution, passivation) was found to modify the tribological conditions (friction coefficient). (author)

Irradiation Effects at 160-240 deg C in Some Swedish Pressure Vessel Steels

Energy Technology Data Exchange (ETDEWEB)

Grounes, M [AB Atomenergi, Nykoeping (Sweden); Myers, H P [Chalmers Institute of Technology, Goeteborg (Sweden); Hannerz, N E [Motala Verkstads AB, Motala (Sweden)

1967-09-15

Tensile specimens, Charpy impact specimens and miniature impact specimens of six steels in different conditions were irradiated to 2.8 x 10{sup 18} and 5.6 x 10{sup 18} n/cm{sup 2} (> 1 MeV) at 160-240 deg C. The steels investigated were SIS 142103, 2103/R3, NO 345, Fortiweld, Fortiweld HS and OK 54 P. There is no correlation between the increase in transition temperature and initial transition temperature. However, changes in strength and ductility can be correlated to the initial yield strength. The increases in transition temperature due to strain aging and irradiation are approximately additive. The irradiation-induced changes in 2103/R3 and Fortiweld HS steels do not vary with position in the thickness of the plate. Different tempering treatments in Fortiweld HS steel do not change the extent of irradiation effects. Normal Charpy V-notch impact specimens and miniature specimens give the same irradiation-induced increase in transition temperature.

Irradiation Effects at 160-240 deg C in Some Swedish Pressure Vessel Steels

International Nuclear Information System (INIS)

Grounes, M.; Myers, H.P.; Hannerz, N.E.

1967-09-01

Tensile specimens, Charpy impact specimens and miniature impact specimens of six steels in different conditions were irradiated to 2.8 x 10 18 and 5.6 x 10 18 n/cm 2 (> 1 MeV) at 160-240 deg C. The steels investigated were SIS 142103, 2103/R3, NO 345, Fortiweld, Fortiweld HS and OK 54 P. There is no correlation between the increase in transition temperature and initial transition temperature. However, changes in strength and ductility can be correlated to the initial yield strength. The increases in transition temperature due to strain aging and irradiation are approximately additive. The irradiation-induced changes in 2103/R3 and Fortiweld HS steels do not vary with position in the thickness of the plate. Different tempering treatments in Fortiweld HS steel do not change the extent of irradiation effects. Normal Charpy V-notch impact specimens and miniature specimens give the same irradiation-induced increase in transition temperature

Development of plastic deformations in 12Kh18N10T steel under cyclic symmetrical bending of specimens of various length

Energy Technology Data Exchange (ETDEWEB)

Pisarenko, G.S.; Leonets, V.A.; Bega, N.D. (AN Ukrainskoj SSR, Kiev. Inst. Problem Prochnosti)

1983-08-01

Effect of specimen length on intensity of plastic deformation development and cyclic strength is studied for annealed 12Kh18N10T steel under cyclic symmetrical bending. The intensity of microplastic deformations and cyclic strength of annealed 12Kh18N10T steel in the considered case is due to self-heating.

Investigation of behaviour of the hexanite-R during microcutting of titanium and steel

International Nuclear Information System (INIS)

Samsonov, G.V.; Pilyankevich, A.N.; Adamovskij, A.A.; Bochko, A.V.; Dzhamarov, S.S.; Balan, T.R.

1976-01-01

A study has been made of hexanite-R in the process of microcutting titanium and steel, whose conditions simulate the behaviour of the grain of the abrasive disk. It is shown that in the grindings of the metals with high cutting speeds the deciding influence on the grain wear is produced by the chemical activity of the grain with respect to the metal under treatment, whereas the initial hardness of the abrasive material does not exert any appreciable effect on the wear. The adhesion type of hexanite-R wear will be typical of titanium grinding, and the abrasive type - of steel grinding. In the abrasive-metal friction couple the combined action of pressures and temperature causes the electron exchange between the contacting couples, which explains the wear of the materials brought into contact

Microstructure and Mechanical Properties of Fe-18Mn-18Cr-0.5N Austenitic Nonmagnetic Stainless Steel in Asymmetric Hot Rolling

Science.gov (United States)

Song, Y. L.; Li, C. S.; Ma, B.; Han, Y. H.

2017-05-01

Asymmetric hot rolling (ASHR) with a mismatch speed ratio of 1.15 in a single pass was applied to Fe-18Mn-18Cr-0.5N steel and was compared with symmetric hot rolling (SHR). The results indicated that a through-thickness microstructure gradient was formed in the plate due to the shear strain (0.36) introduced by ASHR. A fine-grained layer with the average size of 3 μm was achieved at the top surface of ASHR plate, while numerous elongated grains with a few recrystallized grains were presented at the center layer. The texture was distributed randomly at the top surface of ASHR plate, and a weaker intensity of typical hot-rolled texture in austenitic steel was obtained at the center layer of ASHR plate compared to SHR plate. An excellent combination of microhardness, strength and ductility was obtained in the ASHR plate, which was attributed to gradient microstructure induced by ASHR.

Susceptibility to stress corrosion in stainless steels type AISI 321 and 12X18H10T used in PWR type reactors (WWER)

International Nuclear Information System (INIS)

Matadamas C, N.

1995-01-01

Titanium stabilized stainless steels have been utilized in sovietic pressurized water reactors (VVER) for avoid the susceptibility to Intergranular Corrosion (IGC) present in other austenitic stainless steels. However the Intergranular Corrosion resistance of this kind of materials has been questioned because of Intergranular Stress Corrosion Cracking failures (IGSCC) have been reported. This paper study the electrochemical behavior of the AISI 321 stainless steel in a H 3 BO 3 Solution contaminated with chlorides and its susceptibility to Intergranular Corrosion.Electrochemical prediction diagrams of the stainless steels AISI 321 and 12X18H10T (sovietic) sensitized (600 Centigrade, 3 h.) were compared. Cylindrical and conical samples were used in Slow Strain Rate Tests (SSRT), to determine the susceptibility to Stress Corrosion Cracking (SCC) in AISI 321 and 12X18H10T stainless steels. The results obtained showed that the temperature of the solution is a very important factor to detect this susceptibility. Fractography studies on the fracture surfaces of the samples obtained in the SSRT at high temperature were realized. Corrosion velocities of both AISI 321 and 12X18H10T stainless steels were determined using conical samples in the CERT system at high temperature. E.D.A.X. analysis was employed in both AISI 321 and 12X18H10T stainless steels in order to explain the degree of sensitization. (Author)

Changes in mechanical properties and structure of electrolytic plasma treated X 12 CrNi 18 10 Ti stainless steel

Energy Technology Data Exchange (ETDEWEB)

Kurbanbekov, Sherzod; Baklanov, Viktor; Karakozov, Batyrzhan [Republican State Enterprise National Nuclear Center of Kazakhstan, Kurchatov (Kazakhstan). Inst. of Atomic Energy Branch; Skakov, Mazhyn [Republican State Enterprise National Nuclear Center of Kazakhstan, Kurchatov (Kazakhstan)

2017-05-01

The paper addresses findings regarding the influence of electrolytic plasma treatment on the mechanical properties as well as structural and phase states of X 12 CrNi 18 10 Ti steel. Electrolytic plasma treatment is based on carburizing of stainless steel heated in electrolytes. Treatment of steel samples has been performed as follows: the samples were heated up to a temperature between 850 and 950 C and then they were cured for 7 minutes in an electrolyte of an aqueous solution containing 10 % glycerol (C{sub 3}H{sub 8}O{sub 3}) and 15 % sodium carbonate (Na{sub 2}CO{sub 3}). It is found that, after plasma electrolytic treatment, the surface of X 12 CrNi 18 10 Ti steel had a modified structure and high hardness. Increasing wear resistance of X 12 CrNi 18 10 Ti steel has been observed after carburizing and the coefficient of friction has been reduced. X-ray analysis showed that retained austenite γ-Fe is a main phase, and there are some diffraction lines of orthorhombic Fe{sub 3}C phase as well as Fe{sub 3}O{sub 4} cubic phase. It has been determined, that, after plasma electrolytic treatment, a carbide phase in the modified surface layer, irrespective of the location in the steel structure has the chemical composition Fe{sub 3}C. High concentration of carbon atoms in a solid solution based on γ- and α-iron, a large dislocation density, presence of particles of carbide phase and retained austenite layers have been found.

Creep and microstructural processes in a low-alloy 2.25%Cr1.6%W steel (ASTM Grade 23)

Czech Academy of Sciences Publication Activity Database

Kuchařová, Květa; Sklenička, Václav; Kvapilová, Marie; Svoboda, Milan

2015-01-01

Roč. 109, NOV (2015), s. 1-8 ISSN 1044-5803 R&D Projects: GA TA ČR TA02010260; GA MŠk(CZ) ED1.1.00/02.0068 Institutional support: RVO:68081723 Keywords : Bainitic steel * Low-alloy steel * Creep strength * Microstructural changes * Carbide precipitation Subject RIV: JG - Metallurgy Impact factor: 2.383, year: 2015

Influence of Mn contents in 0Cr18Ni10Ti thin wall stainless steel tube on TIG girth weld quality

Science.gov (United States)

Liu, Bo

2017-03-01

Three kinds of cold worked 0Cr18Ni10Ti thin wall stainless steel tubes with the manganese contents of 1.27%, 1.35% and 1.44% and the cold worked 0Cr18Ni10Ti stainless steel end plug with manganese content of 1.35% were used for TIG girth welding in the present investigation. The effect of different manganese contents in stainless steel tube on weld quality was studied. The results showed that under the same welding conditions, the metallographic performance of the girth weld for the thin wall stainless steel tube with the manganese element content 1.44% welded with end plug was the best. Under the appropriate welding conditions, the quality of the girth weld increased with the increase of the manganese content till 1.44%. It was found that in the case of the Mn content of 1.44%, and under the proper welding condition the welding defects, such as welding cracks were effectively avoided, and the qualified weld penetration can be obtained.. It is concluded that the appropriate increase of the manganese content can significantly improve the TIG girth weld quality of the cold worked 0Cr18Ni10Ti stainless steel tube.

Low-temperature cyclic cracking resistance of Fe-Cr-Ni and Fe-Cr-Mn steels welded joints

International Nuclear Information System (INIS)

Ostash, O.P.; Zhmur-Klimenko, V.T.; Yarema, S.Ya.; Yushchenko, K.A.; Strok, L.P.; Belotserkovets, V.I.

1983-01-01

Results of further investigations into regularities of development of low-temperature fatigue fracture of welded oints in 07Kh13G20AN4 steel are presented, they are compared with analogous data traditional cryogenic 0Kh18N10T and 03Kh13AG19 steels. Welded joints have been prepared by means of automatic V-like level arc Welding of plates; 0Kh18N10T and 07Kh13G20AN4 steels have been welded by means of sv-04Kh19N9 wire, 03Kh13AG19 steel-by means of sv-07Kh13AG19 wire. Tests at almost zero (asymmetry coefficient R=0.05) cycle of extension at 15-20 Hz frequency have been conducted on 5 mm thick disk samples at 20 deg C and - 160 deg C according to the given methods. It is shown that by cyclic crack resistance of welded joint zones of 0Kh18N10T steel and chromium-manganese steels at normal temperature the 07Kh13G20AN4 steel exceeds 0Kh18N10T steel, at low temperature it yields to 0Kh18N10T only by fracture toughness of heat affected zones HAZ and weld metal (ne). 07Kh13G20AN4 steel and its welded joints as most hardened and cheap may be a good substituent for 0Kh18N10T steel. Optimization of WM alloying for increase of its cyclic fracture toughness at cryogenic temperatures is necessary

Borated stainless steel storage project to the spent fuel of the IEA-R1 reactor

International Nuclear Information System (INIS)

Rodrigues, Antonio Carlos Iglesias; Madi Filho, Tufic; Ricci Filho, Walter

2013-01-01

The IEA-R1 research reactor operates in a regimen of 64h weekly, at the power of 4.5 MW. In these conditions, the racks to the spent fuel elements have less than half of its initial capacity. Thus, maintaining these operating circumstances, the storage will have capacity for approximately six years. Whereas the estimated useful life of the IEA-R1 is around twenty years, it will be necessary to increase the storage capacity for the spent fuel. Dr. Henrik Grahn, expert of the International Atomic Energy Agency on wet storage, visiting the IEA-R1 Reactor (September/2012) made some recommendations: among them, the design and installation of racks made with borated stainless steel and internally coated with an aluminum film, so that corrosion of the fuel elements would not occur. This work objective is the project of high capacity storage for spent fuel elements, using borated stainless steel, to answer the Reactor IEA-R1 demand and the security requirements of the International Atomic Energy Agency. (author)

Borated stainless steel storage project to the spent fuel of the IEA-R1 reactor

Energy Technology Data Exchange (ETDEWEB)

Rodrigues, Antonio Carlos Iglesias; Madi Filho, Tufic; Ricci Filho, Walter, E-mail: acirodri@ipen.br, E-mail: tmfilho@ipen.br, E-mail: wricci@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

2013-07-01

The IEA-R1 research reactor operates in a regimen of 64h weekly, at the power of 4.5 MW. In these conditions, the racks to the spent fuel elements have less than half of its initial capacity. Thus, maintaining these operating circumstances, the storage will have capacity for approximately six years. Whereas the estimated useful life of the IEA-R1 is around twenty years, it will be necessary to increase the storage capacity for the spent fuel. Dr. Henrik Grahn, expert of the International Atomic Energy Agency on wet storage, visiting the IEA-R1 Reactor (September/2012) made some recommendations: among them, the design and installation of racks made with borated stainless steel and internally coated with an aluminum film, so that corrosion of the fuel elements would not occur. This work objective is the project of high capacity storage for spent fuel elements, using borated stainless steel, to answer the Reactor IEA-R1 demand and the security requirements of the International Atomic Energy Agency. (author)

Influence of microstructure on impact properties of 9–18%Cr ODS steels for fusion/fission applications

Czech Academy of Sciences Publication Activity Database

Hadraba, Hynek; Fournier, B.; Stratil, Luděk; Malaplate, J.; Rouffié, A.-L.; Wident, P.; Ziolek, L.; Béchade, J.-L.

2011-01-01

Roč. 411, 1-3 (2011), s. 112-118 ISSN 0022-3115 R&D Projects: GA ČR GA106/08/1397 Institutional research plan: CEZ:AV0Z20410507 Keywords : ODS steel * extrusion shape * crystallographic texture * morphologic texture * brittle fracture mechanisms Subject RIV: JG - Metallurgy Impact factor: 2.052, year: 2011

Neutron metrology in the HFR. Steel irradiation R139-697/698

International Nuclear Information System (INIS)

Hoving, A.H.; Voorbraak, W.P.

1996-06-01

The experiment R139-697/698, for testing the austenitic stainless steel type AISI-316 TIG, has been irradiated in the HFR Petten. This report presents the final metrology results obtained from activation monitors in the specimen holders, coded as R139/697 and R139/698. Data about the helium production as well as the number of displacements per atom are also included. The irradiation conditions for this experiment, carried out in a TRIO type capsule in HFR position F2, are as close as possible relevant for the candidate materials which will be used for the first wall of the NET (Next European Torus). The main results of the thermal and fast neutron fluence mesurements are presented in table 2 and 3 as well as in figures 3 and 4. (orig.)

Structural changes in surface layer of steel 08Kh18N10T during machining

International Nuclear Information System (INIS)

Palenik, J.; Vodarek, V.

1989-01-01

The results are reported of a study of the surface layer of steel 08Kh18N10T affected by machining. Structural changes were studied caused by finish turning and by additional roller burnishing. Multiple deformation bands were observed to occur under the given cutting conditions; they mainly consisted of deformation doublets and only in isolated cases of ε-martensite. The presence of α'-martensite was not shown in the specimen surface layer following finish turning. The deformation shear bands in the roller-burnished specimen consisted of both ε-martensite and of deformation doublets. The amount of ε-martensite in the structure was significantly higher than in the specimen worked by turning. Local presence of α'-martensite formations was observed inside the deformation bands. It thus follows that roller burnishing is unsuitable as part of the manufacture of components from steel 08Kh18N10T. (J.B.). 5 figs., 1 tab., 9 refs

Fabrication of Hadfield-Cored Multi-layer Steel Sheet by Roll-Bonding with 1.8-GPa-Strength-Grade Hot-Press-Forming Steel

Science.gov (United States)

Chin, Kwang-Geun; Kang, Chung-Yun; Park, Jaeyeong; Lee, Sunghak

2018-05-01

An austenitic Hadfield steel was roll-bonded with a 1.8-GPa-strength-grade martensitic hot-press-forming (HPF) steel to fabricate a multi-layer steel (MLS) sheet. Near the Hadfield/HPF interface, the carburized and decarburized layers were formed by the carbon diffusion from the Hadfield (1.2%C) to HPF (0.35%C) layers, and could be regarded as kinds of very thin multi-layers of 35 μm in thickness. The tensile test and fractographic data indicated that the MLS sheet was fractured abruptly within the elastic range by the intergranular fracture occurred in the carburized layer. This was because C was mainly segregated at prior austenite grain boundaries in the carburized layer, which weakened grain boundaries to induce the intergranular fracture. In order to solve the intergranular facture problem, the MLS sheet was tempered at 200 °C. The stress-strain curve of the tempered MLS sheet lay between those of the HPF and Hadfield sheets, and a rule of mixtures was roughly satisfied. Tensile properties of the MLS sheet were dramatically improved after the tempering, and the intergranular fracture was erased completely. In particular, the yield strength up to 1073 MPa along with the high strain hardening and excellent ductility of 32.4% were outstanding because the yield strength over 1 GPa was hardly achieved in conventional austenitic steels.

Experimental study on kinematic hardening of 1Cr18Ni9Ti stainless steel under low cycle fatigue

International Nuclear Information System (INIS)

Shao Er; Yang Xianjie; Mao Jianghui; Sun Yafang

2006-01-01

To study the effect of the monotonic loading on subsequent cyclic plastic hardening and flow properties of 1Cr18Ni9Ti steel, an experimental study of the low cycle fatigue tests with mean strains for 1Cr18Ni9Ti stainless steel was carried out. An analysis on the evolutions of the yield surface radius and the back stresses under symmetric and asymmetric cyclic strain loading with different strain amplitudes was made. The dependence of the evolutions of the material kinematic hardening and isotropic hardening on the strain amplitude and mean strain was observed. These results provide the experimental foundation for the constitutive model of the material under combined monotonic and cyclic complicated loads. (authors)

Effect of high-temperature exposure on the mechanical properties of 18Cr–8Ni–W–Nb–V–N stainless steel

International Nuclear Information System (INIS)

Nikulin, I.; Kipelova, A.; Kaibyshev, R.

2012-01-01

Highlights: ► Niobium stabilized 18Cr–8Ni austenitic steel was subjected to long-time aging. ► The main phases precipitated during aging are Z-phase and Laves-phase. ► Intragranular phases and solid solution are responsible for tensile strength. ► Intergranular particles affect impact toughness. - Abstract: The change in the mechanical properties of 18Cr–8Ni–W–Nb–V–N austenitic stainless steel due to aging was investigated at room temperature and 650 °C. It was shown that long-term aging decreases strength characteristics despite increasing hardness. The impact toughness decreases from 255 J/cm 2 for an un-aged steel to 135 J/cm 2 for the steel aged for 3000 h. However, evidence of ductile fracture was found even after long-term aging. This study suggests that the reduction in impact toughness occurs due to the precipitation of Z-phase and Laves-phase particles at the grain boundaries. The degradation of impact toughness and mechanical properties with aging is discussed in terms of microstructure evolution, secondary phase precipitations and fracture mechanisms.

The structure of the alphinizing coat on alloy steels

Directory of Open Access Journals (Sweden)

S. Pietrowski

2008-12-01

Full Text Available In this paper results of the structure of the coat alphinizing in AlSi5 silumin on alloy steels: acid-proof 1H18N9T (X6CrNiTi18-10 and high speed SW18 (HS18-0-1 were presented. The temperature of the alphinizing bath was amounts to750±5°C, and immersion time of the element τ = 180s. It was shown, that there is the different “g” coat thickness on testing steels. On the 1H18N9T steel it amounts to g = 52μm, and on the SW18 steel – g = 203μm. Regardless of a grade of testing alloy steels the coat consist of three layers with diversified phasic structure. There is different chemical composition of coat layers on testing steels. The first layer from the base consist of AlFe phase containing alloy addictions of steels: Cr and Ni (1H18N9T and W, V and Cr (SW18. On this layer crystallize the second layer of intermetallic phases. It is the phase containing the main alloy addiction of steels: AlFeCr (1H18N9T and AlFeW (SW18. The last, outside layer consist of silumin containing AlFeNi intermetallic phases on the 1H18N9T steel and AlFeW on the SW18 steel. Regardless of the grade of testing steels there is Si element in all layers of the coat. There are morphological differences in tested layers. The second layer (AlFeW phase inside the coat on the SW18 steel consist of faced crystals growing into in outside silumin layer. On the 1H18N9T steel a boundary between transient and outside layer is more uniform. Free separations of intermetallic phases inside silumin layer on the 1H18N9T steel have lamellar and on the SW18 steel – faced form.

Structural evolution of Fe-18Ni-16Cr-4Al steel during aging at 950 .deg. C

Energy Technology Data Exchange (ETDEWEB)

Wang, Man; Jang, Jinsung [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Zhou, Zhangjian [School of Materials Science and Engineering, USTB, Beijing (China)

2015-05-15

Austenitic stainless steels are also among important structural materials for in-core components of nuclear reactors, and the performance, the oxidation resistance as well as the mechanical strength at high temperature are further expected after Fukushima accident. Alumina-forming austenitic (AFA) steel was first developed by Y. Yamamoto et al. , which showed a good combination of oxidation resistance and creep resistance. The strengthening is achieved through nano-sized MX and Laves. Microstructural evolution of Fe-18Ni-16Cr-4Al during aging at 950 .deg. C was studied. This steel consists of two phases of austenite and ferrite. During aging, needle-shaped NiAl precipitates in austenite, while round shaped NiAl form in ferrite, which is supposed to be due to different crystal structural parameters.

Self-protective powder wire for semiautomatic welding of corrosion resistant chromium-nickel type 18-10 steels

International Nuclear Information System (INIS)

Lipodaev, V.N.; Kakhovskij, N.I.; Fadeeva, G.V.

1977-01-01

Self-protecting NP-ANV1 powder wire has been developed for welding 18-10 type stainless steels. The use of the wire provides for the same running properties of the welds as the TsL-11 electrodes, the welding being 3-5 times more efficient

Influence of ion implanted helium on deuterium trapping in Kh18N10T stainless steel

International Nuclear Information System (INIS)

Tolstolutskaya, G.D.; Ruzhitskij, V.V.; Kopanets, I.E.

2004-01-01

The results are presented on evolution of distribution profiles and helium and deuterium thermal desorption ion implanted in steel 18Cr10NiTi. Accumulation, trapping, retention and microstructure evolution are studied; effect helium and hydrogen simultaneous implantation on these processes is also studied

Friction and wear behaviour of 18 polymers in contact with steel in environments of air and water

NARCIS (Netherlands)

Mens, J.W.M.; de Gee, A.W.J.

1991-01-01

18 polymers were characterized with respect to their friction and wear behaviour in contact with steel in environments of air and water. These were six unfilled materials, i.e. polyamide 66 (PA 66), polyoxymethylene (POM), polyethyleneterephthalate (PETP), polyetheretherketone (PEEK),

Neutron metrology in the HFR. Steel irradiation R139-699 (SINAS)

International Nuclear Information System (INIS)

Baard, J.H.; Paardekooper, A.

1996-06-01

The aim of the irradiation of experiment R139-699 was the testing of austenitic stainless steel type AISI-316 TIG. This report presents the final metrology results obtained from activation monitors in the specimen holder, coded as R139-699. Data about the helium production as well as the number of displacements per atom are also included. The irradiation circumstances for this experiment, carried out in a TRIO type capsule in HFR position F2, are as close as possible relevant for the candidate materials which will be used for the first wall of the NET (Next European Torus). The main results of the thermal and fast neutron fluence measurements are presented in tables 2 and 3 as well as in the figure 2. (orig.)

Neutron metrology in the HFR. Steel irradiation R139-805 (SINAS)

International Nuclear Information System (INIS)

Baard, J.H.

1996-10-01

The experiment R139-80 is part of a material program to test austenitic stainless steel of different types and has been irradiated in the HFR Petten. This report presents the final metrology results obtained from activation monitors in the specimen holder, coded as R139-805. Data about the helium production as well as the number of displacements per atom are included. The irradiation circumstances for this experiment, carried out in a TRIO type capsule in HFR position F2, represent the conditions at the first wall of NET (Next European Torus). The aim of this irradiation for specimen holder R139-805 was to reach a damage level of 2.4 dpa at a temperature of 325 C. However, the specimens have been irradiated up to a damage level of 1.7-2.0 dpa. The main results of the thermal and fast neutron fluence measurements are presented in tables 2 and 3 as well as in the figure 2. (orig.)

The effects of adding molybdenum and niobium on the creep strength of 18Cr-10Ni-20Co austenitic steel

International Nuclear Information System (INIS)

Tomono, Yutaka

1987-01-01

The decrease in the creep strength of structural materials during service at elevated temperatures is a very important problem that affects the security of plants and machinery. The improvement in the creep strength of 18Cr-10Ni-20Co austenitic steel achieved through the addition of molybdenum and niobium was studied in tests carried out at 973K and 1,073K. The creep strengthening mechanism was examined using transmission electron micrographs, X-ray diffraction, etc. The results obtained are summarized as follows: (1) The creep strength of low C-18Cr-10Ni-20Co austenitic steel with molybdenum was greatly improved by the addition of niobium up to 1% by weight. In the case of long-term creep, no trend toward decreasing creep strength was observed. (2) The creep strength of austenitic steel possessing a matrix strengthened with molybdenum can be improved through the addition of niobium combined with precipitation hardening with fine carbides precipitated in the grains. (author)

Braze alloy process and strength characterization studies for 18 nickel grade 200 maraging steel with application to wind tunnel models

Science.gov (United States)

Bradshaw, James F.; Sandefur, Paul G., Jr.; Young, Clarence P., Jr.

1991-01-01

A comprehensive study of braze alloy selection process and strength characterization with application to wind tunnel models is presented. The applications for this study include the installation of stainless steel pressure tubing in model airfoil sections make of 18 Ni 200 grade maraging steel and the joining of wing structural components by brazing. Acceptable braze alloys for these applications are identified along with process, thermal braze cycle data, and thermal management procedures. Shear specimens are used to evaluate comparative shear strength properties for the various alloys at both room and cryogenic (-300 F) temperatures and include the effects of electroless nickel plating. Nickel plating was found to significantly enhance both the wetability and strength properties for the various braze alloys studied. The data are provided for use in selecting braze alloys for use with 18 Ni grade 200 steel in the design of wind tunnel models to be tested in an ambient or cryogenic environment.

Determination of susceptibility to intergranular corrosion of stainless steels type X5CrNi18-10 in field

Directory of Open Access Journals (Sweden)

Bore V. Jegdic

2016-12-01

Full Text Available In this paper, the DL EPR method (electrochemical potentiokinetic reactivation with double loop was modified and used to study the susceptibility to intergranular corrosion and stress corrosion cracking of a stainless steel type X5CrNi18-10. The tests were performed in a special electrochemical cell, with the electrolyte in the gel form. Modified DL EPR method is characterized by simple and high accuracy measurements as well as repeatability of the test results. The indicator of susceptibility to intergranular corrosion (Qr/QpGBA obtained by modified DL EPR method is in a very good agreement with the same indicator obtained by standard DL EPR method. The modified DL EPR method is quantitative and highly selective method. Small differences in the susceptibility of the stainless steel type CrNi18-10 to intergranular corrosion and stress corrosion cracking can be determined. Test results can be obtained in a short time. The cost of tests performed by modified DL EPR method is much lower than the cost of tests by conventional chemical methods. Modified DL EPR method can be applied in the field on the stainless steels constructions.

Analysis of the austenitic stainless steel's r-value behavior at elevated temperatures

OpenAIRE

Dušan Arsić; Milan Djordjević; Srbislav Aleksandrović; Vukić Lazić; Ruzica R. Nikolic; Branislav Hadzima

2015-01-01

An analysis of the anisotropy properties of austenitic steel AISI 304 (X5CrNi18-10) at elevated temperatures is presented in this paper. Considerations of the anisotropy problems are presented in the theoretical part of the paper, as well as the procedure for determination of the normal anisotropy coefficient. The experimental part of the paper describes the plan, methodology and equipment for testing of material's normal anisotropy and mechanical characteristics. The objective of conducting ...

Polymorphisms of ST2-IL18R1-IL18RAP gene cluster: a new risk for autoimmune thyroid diseases.

Science.gov (United States)

Wang, X; Zhu, Y F; Li, D M; Qin, Q; Wang, Q; Muhali, F S; Jiang, W J; Zhang, J A

2016-02-01

Interleukin 33 (IL33) / ST2 pathway and ST2-interlukin18 receptor1-interlukin18 receptor accessory protein (ST2-IL18R1-IL18RAP) gene cluster have been involved in many autoimmune diseases but few report in autoimmune thyroid diseases (AITD). In this study, we investigated whether polymorphisms of IL33, ST2, IL18R1, and IL18RAP are associated with Graves' disease (GD) and Hashimoto's thyroiditis (HT), two major forms of AITD, among a Chinese population. A total of 11 SNPs were explored in a case-control study including 417 patients with GD, 250 HT patients and 301 controls, including rs1929992, rs10975519, rs10208293, rs6543116, rs1041973, rs3732127, rs11465597, rs1035130, rs2293225, rs1035127, rs917997 of IL 33, ST2-IL18R1-IL18RAP gene cluster. Genotyping of these SNPs was performed using matrix-assisted laser desorption / ionization-time-of-flight mass spectrometer (MALDI-TOF-MS) platform from Sequenom. The frequencies of allele A and AA+AG genotype of rs6543116 (ST2) in HT patients were significantly increased compared with those of the controls (P = 0.029/0.021, OR = 1.31/1.62). And in another SNP rs917997, AA+AG genotype presented an increased frequency in HT subjects compared with controls (P = 0.046, OR = 1.53). Furthermore, the haplotype GAGCCCG from ST2-IL18R1-IL18RAP gene cluster (rs6543116, rs1041973, rs1035130, rs3732127, rs1035127, rs2293225, rs917997) was associated with increased susceptibility to GD with an OR of 2.03 (P = 0.022, 95% CI = 1.07-3.86). Some SNPs of ST2-IL18R1-IL18RAP gene cluster might increase the risk of susceptibility of HT and GD in Chinese Han population. © 2015 John Wiley & Sons Ltd.

Elastic-plastic fracture analysis of carbon steel piping using the latest CEGB R6 approach

International Nuclear Information System (INIS)

Kanno, S.; Hasegawa, K.; Shimizu, T.; Kobayashi, H.

1991-01-01

The elastic-plastic fracture of carbon steel piping having various pipe diameters and circumferential crack angles and subjected to a bending moment is analyzed using the latest United Kingdom Central Electricity Generating Board R6 approach. The elastic-plastic fracture criterion must be applied instead of the plastic collapse criterion with increase of the pipe diameter and the crack angle. A simplified elastic-plastic fracture analysis procedure based on the R6 approach is proposed. (author)

Optimization of consolidation parameters of 18Cr-ODS ferritic steel through microstructural and microtexture characterization

Science.gov (United States)

Dash, Manmath Kumar; Mythili, R.; Dasgupta, Arup; Saroja, S.

2018-04-01

This paper reports the optimization of consolidation process based on the evolution of microstructure, microtexture and densification in 18%-Cr Oxide Dispersion Strengthened steel. The steel powder of composition Fe-18Cr-0.01C-2W-0.25Ti-0.35Y2O3 has been consolidated by cold isostatic pressing (CIP) for green compaction after mechanical milling. Sintering (1000-1250 °C) and hot isostatic pressing (HIP) at 1150 °C has been employed to achieve good densification on compacted CIP specimen. The effect of sintering temperatures on densification behavior was evaluated and sintering at 1150°C was identified to be optimum for achieving good compaction (92% density) and homogeneous polygonal microstructure with a uniform distribution of fine pores. In addition, HIP of CIP product at 1150°C was found to yield a more homogeneous microstructure as compared to sintered product with 97% density. A static/dynamic recrystallization associated with (1 1 1) texture is observed during consolidation process. A statistical comparison has been made based on frequency of grain boundary distribution and associated texture with its theoretical attributes.

Effect of partial oxygen pressure on physicochemical properties of Kh18N10T steel at isothermal oxidation

International Nuclear Information System (INIS)

Alekseev, V.N.; Oshe, E.K.; Fokin, M.N.; Bogdanova, S.V.; Loskutov, A.I.

1990-01-01

Auger-electron spectroscopy, photoelectric polarization, conductometry methods have been used to analyze chemical and defect composition of surface oxide layers, formed on stainless steel Kh18N10T in vacuum (10 -9 - 10 -2 torr) and at temperatures 593-673 K. The boundary conditions of manifestation of extermal behaviour of the dependence of the surface oxide growth rate at isothermal oxidation of this steel are determined. The relation between passivation properties of the surface oxide and the magnitude of the edge angle of the surface wetting with molten tin is revealed

Metallographical procedure for detecting carburized layer in the 12Kh18N10T steel tubes

International Nuclear Information System (INIS)

Najmark, S.I.; Shmalenyuk, R.P.

1977-01-01

The various causes of the tendency to intercrystalline corrosion of stainless steel tubing were studied. 12Kh18N10T steel tube specimens were metallographically investigated to reveal the presence and depth of the carburized layer. Unlubricated specimens and specimens with the graphite-saltpeter lubrication applied on them were austenized in the temperature range from 950 to 1250 deg C and then exposed to a provoking anneal at 650 deg C for 24 h. All the lubricated specimens showed a carbide network along grain boundaries and intercrystalline cracks. The specimens treated without lubrication had no cracks. The method offered can differentiate poor tube cleaning and the undesirable effect of other processing steps on the tubes

Inhibition of quorum sensing-mediated virulence in Serratia marcescens by Bacillus subtilis R-18.

Science.gov (United States)

Devi, Kannan Rama; Srinivasan, Subramaniyan; Ravi, Arumugam Veera

2018-04-13

Serratia marcescens is an opportunistic human pathogen causing various nosocomial infections, most importantly urinary tract infections (UTIs). It exhibits increased resistance towards the conventional antibiotics. This study was aimed to evaluate the anti-virulence effect of a rhizosphere soil bacterium Bacillus subtilis strain R-18 against the uropathogen S. marcescens. First, the bacterial cell-free culture supernatant (CFCS) of B. subtilis strain R-18 was evaluated for its quorum sensing inhibitory (QSI) potential against biomarker strain Chromobacterium violaceum and the test pathogen S. marcescens. The B. subtilis R-18 CFCS effectively inhibited the quorum sensing (QS)-mediated violacein pigment production in C. violaceum and prodigiosin pigment production in S. marcescens. Furthermore, B. subtilis R-18 CFCS was successively extracted with different solvent systems. Of these solvents, B. subtilis R-18 petroleum ether (PE) extract showed inhibition in biofilm formation, protease, lipase, and hemolysin productions in S. marcescens. Fourier transform infrared spectroscopic (FT-IR) analysis revealed the alterations in the cellular components of bacterial cell pellets obtained from B. subtilis R-18 PE extract treated and untreated S. marcescens. The differential gene expression study further validated the downregulation of virulence-associated genes. Characterization of the active principle in B. subtilis R-18 PE extract by gas chromatography-mass spectrometry (GC-MS) analysis showed the presence of multiple compounds with therapeutic values, which could possibly reduce the QS-dependent phenotypes in S. marcescens. Copyright © 2018. Published by Elsevier Ltd.

Hydrogen embrittlement of thermomechanically treated 18Ni Maraging steel

International Nuclear Information System (INIS)

Munford, J.W.; Rack, H.J.; Kass, W.J.

1977-01-01

The influence of thermomechanical treatments on susceptibility to cracking in 100 percent relative humidity air and low pressure (93.3 KPa) gaseous hydrogen has been investigated for 18Ni (350 ksi) Maraging steel. Two thermomechanical treatments were studied, ausforming and marforming and compared with the standard solution treated and aged material. Although little difference exists for the strength and toughness values between these treatments, a two to five-fold increase in the stress intensity threshold for cracking was found for both the ausformed and marformed material. A dramatic difference in cracking kinetics was also apparent as shown by the failure times at comparable stress intensities. Fractographic analysis showed that the primary fracture mode was 100 percent intergranular for the solution treated and aged samples while the ausform and marform failures were predominately quasi-cleavage or intergranular depending on orientation. Finally, permeation and diffusion measurements were conducted on the above materials and these results are correlated with the environmental cracking behavior

Hydrogen embrittlement of thermomechanically treated 18Ni Maraging steel

Energy Technology Data Exchange (ETDEWEB)

Munford, J.W.; Rack, H.J.; Kass, W.J.

1977-01-01

The influence of thermomechanical treatments on susceptibility to cracking in 100 percent relative humidity air and low pressure (93.3 KPa) gaseous hydrogen has been investigated for 18Ni (350 ksi) Maraging steel. Two thermomechanical treatments were studied, ausforming and marforming and compared with the standard solution treated and aged material. Although little difference exists for the strength and toughness values between these treatments, a two to five-fold increase in the stress intensity threshold for cracking was found for both the ausformed and marformed material. A dramatic difference in cracking kinetics was also apparent as shown by the failure times at comparable stress intensities. Fractographic analysis showed that the primary fracture mode was 100 percent intergranular for the solution treated and aged samples while the ausform and marform failures were predominately quasi-cleavage or intergranular depending on orientation. Finally, permeation and diffusion measurements were conducted on the above materials and these results are correlated with the environmental cracking behavior.

Investigating effects of boundary conditions on the evaluation of R-factor of un-braced steel frames

Directory of Open Access Journals (Sweden)

Masood M.M. Irheem

2017-08-01

Full Text Available Design of Structures to resist seismic load depends on the theory of dissipation in elastic of energy that already exists in response modification factor “R-factor”. The main problem in codes gives a constant value for R-factor, since change in boundary conditions of building change in behavior of steel frame structures and that effect on R-factor. This study is an attempt to assess overstrength, ductility and response modification factor of un-braced steel frames under change in boundary conditions as change in the direction of strong axis of column and support type beside to variation in story and bay number to be 9 frame and each frame has 8 different boundary conditions as sum of 72 case for analysis. These frames were analyzed by using nonlinear static “pushover” analysis using SAP2000 program. As a result of this study R-factor does not has a constant value, when change in boundary conditions R-factor directly changes, minimum value of 8 boundary conditions is close to the code value that is mean the code is more conservative and give a large factor of safety. Ductility reduction factor increases with increasing number of story for all boundary conditions, but overstrength has different rule. Response modification factor, overstrength factor and ductility reduction factor decrease when fundamentals period increasing for the studied frames.

Electrochemical behaviour of titanium coated stainless steel by r.f. sputtering in synthetic sweat solutions for electrode applications

International Nuclear Information System (INIS)

Fonseca, C.; Vaz, F.; Barbosa, M.A.

2004-01-01

The r.f. sputtering technique was used to deposit titanium thin films on stainless steel substrates, aiming at the application of the coated samples as skin contact materials for 'dry' active electrodes. In this work the electrochemical behaviour of the coated samples was investigated in synthetic sweat solutions and their performance was compared with that of uncoated stainless steel and bulk titanium. The characterisation of the samples was carried out by electrochemical techniques and scanning electron microscopy. The coated samples displayed corrosion resistance values in synthetic sweat solutions much higher than stainless steel samples and of the same order of the values measured for bulk titanium in the same conditions

Microstructure and mechanical properties of friction stir welded 18Cr–2Mo ferritic stainless steel thick plate

International Nuclear Information System (INIS)

Han, Jian; Li, Huijun; Zhu, Zhixiong; Barbaro, Frank; Jiang, Laizhu; Xu, Haigang; Ma, Li

2014-01-01

Highlights: • We focus on friction stir welding of 18Cr–2Mo ferritic stainless steel thick plate. • We produce high-quality joints with special tool and optimised welding parameters. • We compare microstructure and mechanical properties of steel and joint. • Friction stir welding is a method that can maintain the properties of joint. - Abstract: In this study, microstructure and mechanical properties of a friction stir welded 18Cr–2Mo ferritic stainless steel thick plate were investigated. The 5.4 mm thick plates with excellent properties were welded at a constant rotational speed and a changeable welding speed using a composite tool featuring a chosen volume fraction of cubic boron nitride (cBN) in a W–Re matrix. The high-quality welds were successfully produced with optimised welding parameters, and studied by means of optical microscopy (OM), scanning electron microscopy (SEM), electron back-scattered diffraction (EBSD) and standard hardness and impact toughness testing. The results show that microstructure and mechanical properties of the joints are affected greatly, which is mainly related to the remarkably fine-grained microstructure of equiaxed ferrite that is observed in the friction stir welded joint. Meanwhile, the ratios of low-angle grain boundary in the stir zone regions significantly increase, and the texture turns strong. Compared with the base material, mechanical properties of the joint are maintained in a comparatively high level

The permeation behavior of deuterium through 1Cr18Ni9Ti stainless steel with TiN+TiC-TiN multiple films

International Nuclear Information System (INIS)

Xiong, Y.; Song, J.; Luo, D.; Lei, Q.; Chen, C.

2015-01-01

The prevention of tritium losses via permeation through structure components is an important issue in fusion technology. The production of thin layers on materials with low diffusivity and/or low surface recombination constants (so-called permeation barriers) seems to be the most practical method to reduce or hinder the permeation of tritium through materials. TiN+TiC+TiN multiple films are deposited on the surface of 1Cr18Ni9Ti stainless steel by ion-beam assisted deposition technology. The characteristics of films are tested by XPS ASEM and XRD, which shows that the film are compact and uniform with a thickness of about 15 μm, and have a good adherence with the substrate below 773 K. The diffraction peaks in the XRD patterns for TiC and TiN are broadened, implying that the multiple films are deposited on the surface of 1Cr18Ni9Ti stainless steel. Meanwhile, the C-H bonded CH 4 -appears in the infrared spectra of multiple films, suggesting that the CH 4 - is in a static state, so hydrogen atom cannot migrate from the site bonded with carbon to a neighboring site. The measured deuterium permeability in 1Cr18Ni9Ti stainless steel coated with multiple films is 2-3 orders of magnitude lower than that of pure 1Cr18Ni9Ti stainless steel substrate from 473 K to 773 K. However, this barrier is partly destroyed above 773 K

Evaluation of Pad 18 Spent Mercury Gold Trap Stainless Steel Container Failure

International Nuclear Information System (INIS)

Skidmore, E.

2016-01-01

Failure of the Pad 18 spent mercury gold trap stainless steel waste container is principally attributed to corrosion induced by degradation of plasticized polyvinyl chloride (pPVC) waste packaging material. Dehydrochlorination of pPVC polymer by thermal and/or radiolytic degradation is well-known to evolve HCl gas, which is highly corrosive to stainless steel and other metals in the presence of moisture. Degradation of the pPVC packaging material was likely caused by radiolysis in the presence of tritium gas within the waste container, though other degradation mechanisms (aging, thermo-oxidation, plasticizer migration) over 30 years storage may have contributed. Corrosion was also likely enhanced by the crevice in the container weld design, and may have been enhanced by the presence of tritiated water. Similar non-failed spent mercury gold trap waste containers did not show radiographic evidence of plastic packaging or trapped free liquid within the container. Therefore, those containers are not expected to exhibit similar failures. Halogenated polymers such as pPVC subject to degradation can evolve halide gases such as HCl, which is corrosive in the presence of moisture and can generate pressure in sealed systems.

Evaluation of Pad 18 Spent Mercury Gold Trap Stainless Steel Container Failure

Energy Technology Data Exchange (ETDEWEB)

Skidmore, E. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2016-08-03

Failure of the Pad 18 spent mercury gold trap stainless steel waste container is principally attributed to corrosion induced by degradation of plasticized polyvinyl chloride (pPVC) waste packaging material. Dehydrochlorination of pPVC polymer by thermal and/or radiolytic degradation is well-known to evolve HCl gas, which is highly corrosive to stainless steel and other metals in the presence of moisture. Degradation of the pPVC packaging material was likely caused by radiolysis in the presence of tritium gas within the waste container, though other degradation mechanisms (aging, thermo-oxidation, plasticizer migration) over 30 years storage may have contributed. Corrosion was also likely enhanced by the crevice in the container weld design, and may have been enhanced by the presence of tritiated water. Similar non-failed spent mercury gold trap waste containers did not show radiographic evidence of plastic packaging or trapped free liquid within the container. Therefore, those containers are not expected to exhibit similar failures. Halogenated polymers such as pPVC subject to degradation can evolve halide gases such as HCl, which is corrosive in the presence of moisture and can generate pressure in sealed systems.

R Gnanamoorthy

Indian Academy of Sciences (India)

Home; Journals; Bulletin of Materials Science. R Gnanamoorthy. Articles written in Bulletin of Materials Science. Volume 25 Issue 2 April 2002 pp 109-114 Steels and Alloys. Fretting fatigue in AISI 1015 steel · R Gnanamoorthy R Rosi Reddy · More Details Abstract Fulltext PDF. A small osillatory movement between two ...

INFLUENCE OF MODIFICATION ON THE STRUCTURE AND CHARACTERISTICS OF THE STAINLESS STEEL 12X18H10TL

Directory of Open Access Journals (Sweden)

I. V. Zemskov

2004-01-01

Full Text Available There are given the results of investigation of influence of modification by ferrocerium, FS30RZM30B, FSMG, modifier MN, developed in BNTU, ferromolybdenum on the structure and characteristics of the steel 12X18H10TL.

Investigations on grain boundary segregation energy of phosphorus in 12Cr1MoV steel under elastic stress

Czech Academy of Sciences Publication Activity Database

Zheng, L.; Fu, Y.; Lejček, Pavel; Song, S.; Schmitz, G.; Meng, Y.

2016-01-01

Roč. 18, č. 4 (2016), 506-510 ISSN 1438-1656 R&D Projects: GA ČR GAP108/12/0144 Institutional support: RVO:68378271 Keywords : grain boundary segregation, * stress effect, * phosphorus, * steel Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.319, year: 2016

Tensile strength and creep behaviour of austenitic stainless steel type 18Cr - 12Ni with niobium additions at 700°C

Science.gov (United States)

Sordi, V. L.; Bueno, L. O.

2010-07-01

The effect of niobium additions up to 2.36 wt% on the creep behavior of a series of seven extra low carbon 18Cr-12Ni austenitic stainless steels at 700°C has been investigated. Grain size and hardness measurements, hot tensile tests and constant stress creep tests from 90 to 180 MPa were carried out for each alloy, in the solution treated condition at 1050, 1200 and 1300°C followed by quench in water. The mechanical behavior at high temperature was related to the amount of NbC precipitation occurring during the tests. Solid solution and intermetallic compound effects were also considered. Creep data analysis was done to determine the parameters of the creep power-law equation dot epsilon = A.σn and the Monkman-Grant relation dot epsilon.tmR = K. Niobium-carbide precipitation in these steels reduces the secondary stage dependence of strain rate with applied stress, resulting in n-values which indicate the possibility of operation of various creep mechanisms. The creep strength during the secondary stage is primarily controlled by the amount of NbC available for precipitation. However, the rupture times increase progressively with niobium content, as the amount of undissolved carbide particles in grain boundaries and the Laves phase precipitation increase.

Numerical simulation on temperature field of TIG welding for 0Cr18Ni10Ti steel cladding and experimental verification

International Nuclear Information System (INIS)

Luo Hongyi; Tang Xian; Luo Zhifu

2015-01-01

Aiming at tungsten inert gas (TIG) for 0Cr18Ni10Ti stainless steel cladding for radioactive source, the numerical calculation of welding pool temperature field was carried out through adopting ANSYS software. The numerical model of non-steady TIG welding pool shape was established, the heat enthalpy and Gaussian electric arc heat source model of surface distribution were introduced, and the effects of welding current and welding speed to temperature field distribution were calculated. Comparing the experimental data and the calculation results under different welding currents and speeds, the reliability and correctness of the model were proved. The welding technological parameters of 0Cr18Ni10Ti stainless steel were optimized based on the calculation results and the welding procedure was established. (authors)

The enhancement in wear resistance of W18Cr4V steel by ion implantation

International Nuclear Information System (INIS)

Zhou Ping; Xu Peiguang

1987-01-01

Two new methods of ion implantation were adopted in comparison with nitrogen implantation: carbon monoxide was implanted directly into W18Cr4V steel, and nitrogen was implanted into a deposited titanium film about 1000 A thick. It is shown that higher surface hardness and wear resistance have been achieved. The composition and phase structure of the implanted layer was determined in detail. The wear mechanisms were discussed

A Distinct Inhibitory Function for miR-18a in Th17 Cell Differentiation.

Science.gov (United States)

Montoya, Misty M; Maul, Julia; Singh, Priti B; Pua, Heather H; Dahlström, Frank; Wu, Nanyan; Huang, Xiaozhu; Ansel, K Mark; Baumjohann, Dirk

2017-07-15

Th17 cell responses orchestrate immunity against extracellular pathogens but also underlie autoimmune disease pathogenesis. In this study, we uncovered a distinct and critical role for miR-18a in limiting Th17 cell differentiation. miR-18a was the most dynamically upregulated microRNA of the miR-17-92 cluster in activated T cells. miR-18a deficiency enhanced CCR6 + RAR-related orphan receptor (ROR)γt + Th17 cell differentiation in vitro and increased the number of tissue Th17 cells expressing CCR6, RORγt, and IL-17A in airway inflammation models in vivo. Sequence-specific miR-18 inhibitors increased CCR6 and RORγt expression in mouse and human CD4 + T cells, revealing functional conservation. miR-18a directly targeted Smad4 , Hif1a , and Rora , all key transcription factors in the Th17 cell gene-expression program. These findings indicate that activating signals influence the outcome of Th cell differentiation via differential regulation of mature microRNAs within a common cluster. Copyright © 2017 by The American Association of Immunologists, Inc.

Precipitation kinetics in austenitic 18Cr-30Ni-Nb cast steel

Directory of Open Access Journals (Sweden)

M. Garbiak

2008-08-01

Full Text Available The study presents the results of investigations on the precipitation kinetics in austenitic 18%Cr-30%Ni cast steel stabilised with an addition of 1.84 wt% niobium. Phase analysis of isolates extracted from the alloy subjected to annealing within the temperature range of 600–1000oC during 10–1000 h was made. The phase constitution of the isolates mainly comprised niobium carbides of the NbC type and complex chromium carbides of the Cr23C6 type. In specimens annealed within the temperature range of 700–900oC, a high-silicon G phase was additionally identified. The highest kinetics of the precipitation process was recorded after annealing at the temperatures of 800 and 900oC.

Aging precipitation behavior and its influence on mechanical properties of Mn18Cr18N austenitic stainless steel

Science.gov (United States)

Qin, Fengming; Li, Yajie; He, Wenwu; Zhao, Xiaodong; Chen, Huiqin

2017-11-01

The aging precipitation behavior in Mn18Cr18N austenitic stainless steel was investigated at temperatures from 600 °C to 900 °C. During isothermal aging treatment, the primary precipitate was Cr2N with a = 0.478 nm and c = 0.444 nm, and it preferentially nucleates along initial grain boundaries and gradually grows towards the interior of grains in discontinuous cellular way. Meanwhile, a small amount of granular face-centred cubic M23C6 with a = 1.066 nm also were observed, which mainly form along grain boundaries. The effect of these precipitates on mechanical properties of the alloy was studied. It was found that precipitates result in degeneration of the matrix hardness. Meanwhile, the SEM morphologies of aged tensile sample show that the brittle fracture predominates during deformation, i.e. the fracture mode transforms from intergranular fracture to transgranular fracture with the increasing of aging time. Compared with the solution-treated sample, the strength of the aged tensile samples slightly decreases and plasticity remarkably deteriorates.

Long term properties and microstructural evolution of 18Cr-10Ni-3Cu-Ti-Nb austenitic stainless steel for boiler tube application

Energy Technology Data Exchange (ETDEWEB)

Minami, Y.; Fukui, T.; Ono, T. [TenarisNKK Tubes, Kawasaki, Kanagawa (Japan); Caminada, S. [TenarisDalmine, Dalmine, BG (Italy)

2010-07-01

The allowable tensile stress of 0.1C-18Cr-10Ni-3Cu-Ti-Nb steel (TEMPALOY AA-1; ASME C.C. 2512) is more than 30% higher compared with that of ASME SA-213 Grade TP347H in the temperature range 600-700 C. This high creep rupture strength is obtained by the precipitation of MC and M{sub 23}C{sub 6} carbides, and Cu-rich phase. Long term creep rupture tests over 10{sup 5}h enabled to verify the superior creep rupture strength of this steel. The investigation of microstructural evolution on the creep ruptured and aged specimens has shown the high structural stability of this material. Hardness and impact properties after high temperature aging reveal similar performance as conventional 18-8 stainless steels. Excellent steam oxidation resistance can be achieved by a shot-blasting method. The scale thickness of shot-blasted tube after 1000h at 750 C is below a few micron meters. These results have revealed that the mechanical properties and environmental resistance of this steel enable the use of TEMPALOY AA-1 in the latest generation of advanced USC boiler. (orig.)

U.S. DOE Roundtable and Workshop on Advanced Steel Technologies: Emerging Global Technologies and R&D Opportunities

Energy Technology Data Exchange (ETDEWEB)

Pellegrino, Joan [Energetics, Inc., Columbia, MD (United States); Jamison, Keith [Energetics, Inc., Columbia, MD (United States)

2015-12-01

This report is based on the proceedings of the U.S. DOE Roundtable and Workshop on Advanced Steel Technologies Workshop hosted by Oak Ridge National Laboratory (ORNL) in cooperation with the U.S. Department of Energy s (DOE s) Advanced Manufacturing Office (AMO) on held on June 23, 2015. Representatives from industry, government, and academia met at the offices of the National Renewable Energy Laboratory in Washington, DC, to share information on emerging steel technologies, issues impacting technology investment and deployment, gaps in research and development (R&D), and opportunities for greater energy efficiency. The results of the workshop are summarized in this report. They reflect a snapshot of the perspectives and ideas generated by the individuals who attended and not all-inclusive of the steel industry and stakeholder community.

Milled Die Steel Surface Roughness Correlation with Steel Sheet Friction

DEFF Research Database (Denmark)

Berglund, J.; Brown, C.A.; Rosén, B.-G.

2010-01-01

This work investigates correlations between the surface topography ofmilled steel dies and friction with steel sheet. Several die surfaces were prepared by milling. Friction was measured in bending under tension testing. Linear regression coefficients (R2) between the friction and texture...

Fatigue hardening and softening studies on strain hardened 18-8 austenitic stainless steel

International Nuclear Information System (INIS)

Ramakrishna Prasad, C.; Vasudevan, R.

1976-01-01

Metals when subjected to fatigue harden or soften depending on their previous mechanical history. Annealed or mildly cold worked metals are known to harden while severely cold worked metals soften when subjected to fatigue loading. In the present work samples of austenitic 18-8 steel cold worked to 11% and 22% reduction in area were mounted in a vertical pulsator and fatigued in axial tension-compression. Clear cut effects were produced and it was noticed that these depended on the extent of cold work, the amplitude as well as the number of cycles of fatigue and mean stress if any. (orig.) [de

Tool life equation for blanking 18-8 stainless steel strips

International Nuclear Information System (INIS)

Faura, F.; Lopez, J.; Sanes, J.; Garcia, A.

1998-01-01

Hereinafter it is presented a model for the behaviour and life of circular blanking tool used in sheet forming processes of 18-8 stainless steel (sheet thickness: 1 mm). Frostily it has analyzed the different studies that have previously dealt with this problem. Secondly taking into account recently made experiments, it is proposed a simple formulation to predict tool life with enough reliability. to this purpose it has examined different parameters in the wear process, inferring from these the fundamental parameters that regulate them and about which the different equations have been configurated. Blanking tests were performed using a 20 t press at a speed of 150 strokes/min. Punch materials used in these test were AISI A2 and AISI D2 with diameters between 1.5 and 10 mm. The blanking tests were performed at a clearance between 5 and 20% of the work material thickness. (Author) 8 refs

MiR-18a regulates the proliferation, migration and invasion of human glioblastoma cell by targeting neogenin

International Nuclear Information System (INIS)

Song, Yichen; Wang, Ping; Zhao, Wei; Yao, Yilong; Liu, Xiaobai; Ma, Jun; Xue, Yixue; Liu, Yunhui

2014-01-01

MiR-17-92 cluster has recently been reported as an oncogene in some tumors. However, the association of miR-18a, an important member of this cluster, with glioblastoma remains unknown. Therefore, this study aims to investigate the expression of miR-18a in glioblastoma and its role in biological behavior of U87 and U251 human glioblastoma cell lines. Quantitative RT-PCR results showed that miR-18a was highly expressed in glioblastoma tissues and U87 and U251 cell lines compared with that in human brain tissues and primary normal human astrocytes, and the expression levels were increased along with the rising pathological grades of glioblastoma. Neogenin was identified as the target gene of miR-18a by dual-luciferase reporter assays. RT-PCR and western blot results showed that its expression levels were decreased along with the rising pathological grades of glioblastoma. Inhibition of miR-18a expression was established by transfecting exogenous miR-18a inhibitor into U87 and U251 cells, and its effects on the biological behavior of glioblastoma cells were studied using CCK-8 assay, transwell assay and flow cytometry. Inhibition of miR-18a expression in U87 and U251 cells significantly up-regulated neogenin, and dramatically suppressed the abilities of cell proliferation, migration and invasion, induced cell cycle arrest and promoted cellular apoptosis. Collectively, these results suggest that miR-18a may regulate biological behavior of human glioblastoma cells by targeting neogenin, and miR-18a can serve as a potential target in the treatment of glioblastoma. - Highlights: • MiR-18a was highly expressed in glioblastoma tissues and U87 and U251 cell lines. • Neogenin was identified as the target gene of miR-18a. • Neogenin expressions were decreased along with the rising pathological grades of glioblastoma. • Inhibition of miR-18a suppressed biological behavior of glioma cells by up-regulating neogenin

MiR-18a regulates the proliferation, migration and invasion of human glioblastoma cell by targeting neogenin

Energy Technology Data Exchange (ETDEWEB)

Song, Yichen, E-mail: jeff200064017@163.com [Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang 110004 (China); Wang, Ping, E-mail: pingwang8000@163.com [Department of Neurobiology, College of Basic Medicine, China Medical University, Shenyang 110001 (China); Institute of Pathology and Pathophysiology, China Medical University, Shenyang 110001 (China); Zhao, Wei, E-mail: 15669746@qq.com [Department of Neurobiology, College of Basic Medicine, China Medical University, Shenyang 110001 (China); Institute of Pathology and Pathophysiology, China Medical University, Shenyang 110001 (China); Yao, Yilong, E-mail: yaoyilong_322@163.com [Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang 110004 (China); Liu, Xiaobai, E-mail: paganizonda1991@qq.com [The 96th Class, 7-year Program, China Medical University, Shenyang, Liaoning Province 110001 (China); Ma, Jun, E-mail: majun_724@163.com [Department of Neurobiology, College of Basic Medicine, China Medical University, Shenyang 110001 (China); Institute of Pathology and Pathophysiology, China Medical University, Shenyang 110001 (China); Xue, Yixue, E-mail: xueyixue888@163.com [Department of Neurobiology, College of Basic Medicine, China Medical University, Shenyang 110001 (China); Institute of Pathology and Pathophysiology, China Medical University, Shenyang 110001 (China); Liu, Yunhui, E-mail: liuyh@sj-hospital.org [Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang 110004 (China)

2014-05-15

MiR-17-92 cluster has recently been reported as an oncogene in some tumors. However, the association of miR-18a, an important member of this cluster, with glioblastoma remains unknown. Therefore, this study aims to investigate the expression of miR-18a in glioblastoma and its role in biological behavior of U87 and U251 human glioblastoma cell lines. Quantitative RT-PCR results showed that miR-18a was highly expressed in glioblastoma tissues and U87 and U251 cell lines compared with that in human brain tissues and primary normal human astrocytes, and the expression levels were increased along with the rising pathological grades of glioblastoma. Neogenin was identified as the target gene of miR-18a by dual-luciferase reporter assays. RT-PCR and western blot results showed that its expression levels were decreased along with the rising pathological grades of glioblastoma. Inhibition of miR-18a expression was established by transfecting exogenous miR-18a inhibitor into U87 and U251 cells, and its effects on the biological behavior of glioblastoma cells were studied using CCK-8 assay, transwell assay and flow cytometry. Inhibition of miR-18a expression in U87 and U251 cells significantly up-regulated neogenin, and dramatically suppressed the abilities of cell proliferation, migration and invasion, induced cell cycle arrest and promoted cellular apoptosis. Collectively, these results suggest that miR-18a may regulate biological behavior of human glioblastoma cells by targeting neogenin, and miR-18a can serve as a potential target in the treatment of glioblastoma. - Highlights: • MiR-18a was highly expressed in glioblastoma tissues and U87 and U251 cell lines. • Neogenin was identified as the target gene of miR-18a. • Neogenin expressions were decreased along with the rising pathological grades of glioblastoma. • Inhibition of miR-18a suppressed biological behavior of glioma cells by up-regulating neogenin.

Effect of cold deformation on latent energy value and high-temperature mechanical properties of 12Cr18Ni10Ti steel

International Nuclear Information System (INIS)

Maksimkin, O.P.; Shiganakov, Sh.B.; Gusev, M.N.

1997-01-01

Energetic and magnetic characteristics and also the high-temperature mechanical properties depending on the preliminary cold deformation of 12Cr18Ni10Ti steel are presented. It is shown that the value of storage energy in the steel has being grown with increase of the deformation. The rate of its growth has been increased after beginning of martensitic γ→α'- transformation when value of comparative storage energy at first decreased and then has been stay practically constant. Level of mechanical properties of the steel at 1073 K has been determined not only by value of cold deformation but and structural reconstruction corresponding to deformations 35-45% and accompanying with α'-phase martensite formation and change of energy accumulating rate. Preliminary cold deformation (40-60 %) does not improve high- temperature plasticity of steel samples implanted by helium. refs. 7, figs. 2

Features of argon-arc welding of aluminium alloy AD1 to stainless steel 12Kh18N10T

International Nuclear Information System (INIS)

Sadov, I.I.

1982-01-01

Welding of pipes made of the 12Kh18N10T stainless steel and the AD1 aluminium alloy is proposed to perform using one-sided aluminizing. It is recommended to use shields in order to protect internal and external surfaces of pipes, aluminizing of which is impossible. It is shown that developed technological process for welded joints made of aluminium and stainless steel for cryogenic apparatus permits to create light-duty cryostat assembly using aluminium alloys instead of copper alloys, to increase reliability of apparatus (usage of welded joints instead of soldered ones), and to improve labour conditions

Susceptibility to stress corrosion in stainless steels type AISI 321 and 12X18H10T used in PWR type reactors (WWER); Susceptibilidad a la corrosion bajo esfuerzo de barras de acero inoxidable AISI 321 y 12X18H10T en ambientes utilizados en reactores VVER

Energy Technology Data Exchange (ETDEWEB)

Matadamas C, N

1996-12-31

Titanium stabilized stainless steels have been utilized in sovietic pressurized water reactors (VVER) for avoid the susceptibility to Intergranular Corrosion (IGC) present in other austenitic stainless steels. However the Intergranular Corrosion resistance of this kind of materials has been questioned because of Intergranular Stress Corrosion Cracking failures (IGSCC) have been reported. This paper study the electrochemical behavior of the AISI 321 stainless steel in a H{sub 3}BO{sub 3} Solution contaminated with chlorides and its susceptibility to Intergranular Corrosion.Electrochemical prediction diagrams of the stainless steels AISI 321 and 12X18H10T (sovietic) sensitized (600 Centigrade, 3 h.) were compared. Cylindrical and conical samples were used in Slow Strain Rate Tests (SSRT), to determine the susceptibility to Stress Corrosion Cracking (SCC) in AISI 321 and 12X18H10T stainless steels. The results obtained showed that the temperature of the solution is a very important factor to detect this susceptibility. Fractography studies on the fracture surfaces of the samples obtained in the SSRT at high temperature were realized. Corrosion velocities of both AISI 321 and 12X18H10T stainless steels were determined using conical samples in the CERT system at high temperature. E.D.A.X. analysis was employed in both AISI 321 and 12X18H10T stainless steels in order to explain the degree of sensitization. (Author).

Compactibility of atomized high-speed steel and steel 3 powders

International Nuclear Information System (INIS)

Kulak, L.D.; Gavrilenko, A.P.; Pikozh, A.P.; Kuz'menko, N.N.

1985-01-01

Spherical powders and powders of lammellar-scaly shape of high-speed R6M5K5 steel and steel 3 produced by the method of centrifugal atomization of a rotating billet under conditions of cold pressing in steel moulds are studied for thier compactability. Compacting pressure dependnences are establsihed for density of cold-pressed compacts of spherical and scaly powders. The powders of lammellar-scaly shape both of high-speed steel and steel 3 are found to possess better compactibility within a wide range of pressures as compared to powders of spherical shape. Compacts of the lammellar-scaly powders possess also higher mechanical strength

Shot Peening Effects on Subsurface Layer Properties and Fatigue Performance of Case-Hardened 18CrNiMo7-6 Steel

Directory of Open Access Journals (Sweden)

H. S. Ho

2018-01-01

Full Text Available The present study is conducted with a dual-aim: firstly, to examine the effect of several single shot peening conditions on the subsurface layer properties and fatigue performance of the case-hardened 18CrNiMo7-6 steel, and secondly, to propose an optimized peening condition for improved fatigue performance. By carrying out the subsurface integrity analysis and fatigue testing, the underlying relationships among the peening process, subsurface layer property and fatigue performance are investigated, the way peening conditions affect the fatigue life and its associated scatter for the case-hardened 18CrNiMo7-6 steel is quantitatively assessed. The in-depth study shows that dual peening can be an optimized solution, for it is able to produce a subsurface layer with enhanced properties and eventually gain a significant improvement in fatigue performance.

Assessment of R18, COG1410, and APP96-110 in excitotoxicity and traumatic brain injury

Directory of Open Access Journals (Sweden)

Chiu Li Shan

2017-11-01

Full Text Available Cationic arginine-rich and poly-arginine peptides (referred to as CARPs have potent neuroprotective properties in in vitro excitotoxicity and in vivo models of stroke. Traumatic brain injury (TBI shares many pathophysiological processes as stroke, including excitotoxicity. Therefore, we evaluated our lead peptide, poly-arginine R18, with the COG1410 and APP96-110 peptides, which have neuroprotective actions following TBI. In an in vitro cortical neuronal glutamic acid excitotoxicity injury model, R18 was highly neuroprotective and reduced neuronal calcium influx, while COG1410 and APP96-110 displayed modest neuroprotection and were less effective at reducing calcium influx. In an impact-acceleration closed-head injury model (Marmarou model, R18, COG1410, and APP96-110 were administered intravenously (300 nmol/kg at 30 minutes after injury in male Sprague-Dawley rats. When compared to vehicle, no peptide significantly improved functional outcomes, however the R18 and COG1410 treatment groups displayed positive trends in the adhesive tape test and rotarod assessments. Similarly, no peptide had a significant effect on hippocampal neuronal loss, however a significant reduction in axonal injury was observed for R18 and COG1410. In conclusion, this study has demonstrated that R18 is significantly more effective than COG1410 and APP96-110 at reducing neuronal injury and calcium influx following excitotoxicity, and that both R18 and COG1410 reduce axonal injury following TBI. Additional dose response and treatment time course studies are required to further assess the efficacy of R18 in TBI.

Stress corrosion (Astm G30-90 standard) in 08x18H10T stainless steel of nuclear fuel storage pool in WWER reactors; Corrosion bajo esfuerzo (Norma ASTM G30-90) en acero inoxidable 08x18H10T de piscinas de almacenamiento de combustible nuclear en reactores V.V.E.R

Energy Technology Data Exchange (ETDEWEB)

Herrera, V.; Zamora R, L. [Centro de Estudios Aplicados al Desarrollo Nuclear (Cuba)

1997-07-01

At the water storage of the irradiated nuclear fuel has been an important factor in its management. The actual pools have its walls covered with inoxidable steel and heat exchangers to dissipate the residual heat from fuel. It is essential to control the water purity to eliminate those conditions which aid to the corrosion process in fuel and at related components. The steel used in this research was obtained from an austenitic inoxidizable steel standardized with titanium 08x18H10T (Type 321) similar to one of the two steel coatings used to cover walls and the pools floor. the test consisted in the specimen deformation through an U ply according to the Astm G30-90 standard. The exposition of the deformed specimen it was realized in simulated conditions to the chemical regime used in pools. (Author)

Influence of applied tensile stress on the hysteresis curve and magnetic domain structure of grain-oriented Fe–3%Si steel

Czech Academy of Sciences Publication Activity Database

Perevertov, Oleksiy; Schäfer, R.

2014-01-01

Roč. 47, č. 18 (2014), s. 1-10 ISSN 0022-3727 R&D Projects: GA ČR(CZ) GAP107/11/0391 Grant - others:AVČR(CZ) M100100906 Institutional support: RVO:68378271 Keywords : magnetic domains * magnetization process * magnetoelasticity * hysteresis loops * tension * silicon steel * Kerr microscopy Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 2.721, year: 2014

Corrosion cracking of 03N18K1M3TYu and 02N12Kh5M3 maraging steels in chloride solutions

Energy Technology Data Exchange (ETDEWEB)

Pavlov, V.N.; Chumalo, G.V.; Vereshchagin, A.N.; Melekhov, R.K.

1987-07-01

The authors investigate the electrochemical behavior in 0.5% NaCl solution and 42% MgCl/sub 2/ solution and the tendency toward corrosion cracking was determined in boiling 0.5% chloride solution of the cobalt-containing maraging steels in the title. Weld specimens and specimens of the base metal of 03N18K1M3TYu steel were tested in 3% NaCl solution for resistance to corrosion cracking. Additional investigations were made of specimens of that steel with previously created fatigue cracks of the base metal and the weld specimens in 3% NaCl solutions, since that steel is a promising material for structures operating in sea water and low concentration chloride solutions.

Fatigue damage evolution of cold-worked austenitic nickel-free high-nitrogen steel X13CrMnMoN18-14-3 (1.4452)

Energy Technology Data Exchange (ETDEWEB)

Tikhovskiy, I.; Weiss, S.; Fischer, A. [Univ. of Duisburg-Essen, Materials Science and Engineering II, Duisburg (Germany)

2004-07-01

Due to the fact that the risk of Ni-allergies becomes more and more important for modern therapies, the necessity of Ni-free implant materials becomes increasingly important. Beside Co- and Ti-base alloys Ni-free high-nitrogen steels may offer an attractive alternative. The present work presents the austenitic high-nitrogen and nickel-free steel X13CrMnMoN18-14-3, (Material No.: 1.4452) after 20% cold-working. In addition this material was deformed under axial cyclic total strain controlled fatigue tests at room temperature. The development of dislocation structure due to different loading amplitudes was compared to none cyclically deformed material. The good mechanical und fatigue properties of these austenitic high-nitrogen steels as well as the better tribological, chemical and biological properties compared to CrNiMo-steels qualify these steels as a promising alternative in medical applications. (orig.)

Quality of austenite chrome-nickel steel made by gas-oxygen refining

International Nuclear Information System (INIS)

Fel'dgandler, Eh.G.; Levin, F.L.; Moshkevich, E.A.; Shifrin, Eh.V.; Movshovich, V.S.; Pargamonov, E.A.

1991-01-01

Properties and structure were investigated of austenitic 03Kh18N11 and 08KhN10T steels melted at gas oxygen refining aggregates. It was established that mechanical and corrosion properties of rolling of such steels were in agreement with standard properties of metal of open melting. Sheet 08Kh18N10T steel has the level of strength and plasticity regulated for 12Kh18N10T steel. As steel of 08Kh18N10T holds the complex of high mechanical and corrosion properties, 08Kh18N10T is recommended to be replace by 12Kh18N10T with the aim of decrease of titanium usage and increase of process efficiency

Tensile strength and creep behaviour of austenitic stainless steel type 18Cr - 12Ni with niobium additions at 700{sup 0}C

Energy Technology Data Exchange (ETDEWEB)

Sordi, V L; Bueno, L O, E-mail: sordi@ufscar.b [Federal University of Sao Carlos, Materials Engineering Department, Sao Carlos (SP), 13565-905 (Brazil)

2010-07-01

The effect of niobium additions up to 2.36 wt% on the creep behavior of a series of seven extra low carbon 18Cr-12Ni austenitic stainless steels at 700{sup 0}C has been investigated. Grain size and hardness measurements, hot tensile tests and constant stress creep tests from 90 to 180 MPa were carried out for each alloy, in the solution treated condition at 1050, 1200 and 1300{sup 0}C followed by quench in water. The mechanical behavior at high temperature was related to the amount of NbC precipitation occurring during the tests. Solid solution and intermetallic compound effects were also considered. Creep data analysis was done to determine the parameters of the creep power-law equation {epsilon}-dot = A.{sigma}{sup n} and the Monkman-Grant relation {epsilon}-dot .t{sup m}{sub R} = K. Niobium-carbide precipitation in these steels reduces the secondary stage dependence of strain rate with applied stress, resulting in n-values which indicate the possibility of operation of various creep mechanisms. The creep strength during the secondary stage is primarily controlled by the amount of NbC available for precipitation. However, the rupture times increase progressively with niobium content, as the amount of undissolved carbide particles in grain boundaries and the Laves phase precipitation increase.

Studies on Corrosion of Annealed and Aged 18 Ni 250 Grade Maraging Steel in Sulphuric Acid Medium

OpenAIRE

Poornima, T.; Jagannatha, Nayak; Shetty, A. Nityananda

2010-01-01

The corrosion behavior of aged and annealed sample of 18 Ni 250 grade maraging steel was investigated in varied conditions of concentration and temperature of sulphuric acid medium, using electrochemical techniques like Tafel polarization and electrochemical impedance spectroscopy (EIS). The results obtained from both the techniques are in good agreement. These results have shown increase in corrosion rate of aged specimen with increase in concentration and temperature of sulphuric acid. With...

Design of joints in steel and composite structures Eurocode 3 : design of steel structures : part 1-8 : design of joints, Eurocode 4 : design of composite steel and concrete structures : part 1-1 : general rules and rules for buildings

CERN Document Server

Jaspart, Jean-Pierre

2016-01-01

This book details the basic concepts and the design rules included in Eurocode 3 Design of steel structures Part 1-8 Design of joints. Joints in composite construction are also addressed through references to Eurocode 4 Design of composite steel and concrete structures Part 1-1 General rules and rules for buildings. Attention has to be duly paid to the joints when designing a steel or composite structure, in terms of the global safety of the construction, and also in terms of the overall cost, including fabrication, transportation and erection. Therefore, in this book, the design of the joints themselves is widely detailed, and aspects of selection of joint configuration and integration of the joints into the analysis and the design process of the whole construction are also fully covered. Connections using mechanical fasteners, welded connections, simple joints, moment-resisting joints and lattice girder joints are considered. Various joint configurations are treated, including beam-to-column, beam-to-beam, ...

The effect of cobalt and molybdenum on the creep strength of low C-18Cr-10Ni steel

International Nuclear Information System (INIS)

Tomono, Yutaka; Ueda, Jitsuhiko

1982-01-01

The improvement of creep strength through the addition of cobalt and molybdenum to low C-18Cr-10Ni steel was studied at a temperature range of between 700 and 800 0 C. Changes in mechanical and physical properties such as lattice parameter and stacking fault energy, related to the additional elements were investigated to estimate the strengthening effect. Dislocation structures corresponding to the various creep stages were observed through a transmission electron microscope to distinguish the solution hardening effect of the added elements from the precipitation hardening effects of carbide. The results obtained are summarized as follows: (1) Addition of cobalt of up to 20% by weight improved the creep strength of austenitic steel. Addition of molybdenum of up to 5% by weight remarkably improved the creep strength of austenitic steel having a cobalt content of 20% by weight. (2) The trend for creep strength to improve with the addition of these elements was closely coincident with increases in lattice parameter and did not necessarily coincide with changes in the stacking fault energy. (author)

Taxonomic resolutions based on 18S rRNA genes: a case study of subclass copepoda.

Directory of Open Access Journals (Sweden)

Shu Wu

Full Text Available Biodiversity studies are commonly conducted using 18S rRNA genes. In this study, we compared the inter-species divergence of variable regions (V1-9 within the copepod 18S rRNA gene, and tested their taxonomic resolutions at different taxonomic levels. Our results indicate that the 18S rRNA gene is a good molecular marker for the study of copepod biodiversity, and our conclusions are as follows: 1 18S rRNA genes are highly conserved intra-species (intra-species similarities are close to 100%; and could aid in species-level analyses, but with some limitations; 2 nearly-whole-length sequences and some partial regions (around V2, V4, and V9 of the 18S rRNA gene can be used to discriminate between samples at both the family and order levels (with a success rate of about 80%; 3 compared with other regions, V9 has a higher resolution at the genus level (with an identification success rate of about 80%; and 4 V7 is most divergent in length, and would be a good candidate marker for the phylogenetic study of Acartia species. This study also evaluated the correlation between similarity thresholds and the accuracy of using nuclear 18S rRNA genes for the classification of organisms in the subclass Copepoda. We suggest that sample identification accuracy should be considered when a molecular sequence divergence threshold is used for taxonomic identification, and that the lowest similarity threshold should be determined based on a pre-designated level of acceptable accuracy.

Effect of the thermal ageing on the tensile and impact properties of a 18%Cr ODS ferritic steel

Energy Technology Data Exchange (ETDEWEB)

Rouffié, A.L., E-mail: anne-laure.rouffie@cea.fr [CEA, DEN, DANS, DMN, SRMA, Bât 453, F-91191 Gif-sur-Yvette (France); Mines ParisTech, Centre des Matériaux P.M. Fourt, UMR CNRS 7633, BP 87, 91003 Evry (France); Crépin, J.; Sennour, M. [Mines ParisTech, Centre des Matériaux P.M. Fourt, UMR CNRS 7633, BP 87, 91003 Evry (France); Tanguy, B. [CEA, DEN, DANS, DMN, SEMI, Bât 625, F-91191 Gif-sur-Yvette (France); Pineau, A. [Mines ParisTech, Centre des Matériaux P.M. Fourt, UMR CNRS 7633, BP 87, 91003 Evry (France); Hamon, D.; Wident, P.; Vincent, S. [CEA, DEN, DANS, DMN, SRMA, Bât 453, F-91191 Gif-sur-Yvette (France); Garat, V. [AREVA NP, 10 rue J. Récamier, 69006 Lyon (France); Fournier, B. [Manoir Industries – Petrochem and Nuclear, Metallurgy Dpt., 12 rue des Ardennes, BP 8401 Pitres, 27108 Val de Reuil Cedex (France)

2014-02-01

The effects of the thermal ageing at 400 °C, 500 °C and 600 °C during 5000 h on the mechanical properties of a 18%Cr ODS ferritic steel are investigated. A hardening effect is observed after ageing at 400 °C and 500 °C, probably due to the presence of chromium rich α′ particles as suggested by the literature. The impact resistance and the ductility of the material are strongly lowered by the ageing at 600 °C. This embrittlement is characterized on the fracture surfaces by the presence of cleavage facets on the whole range of testing temperatures. The intermetallic σ phase is found to be responsible for the occurrence of cleavage fracture on the material aged at 600 °C, and thus for the significant embrittlement of this material. M{sub 23}C{sub 6} carbides are also observed before and after thermal ageing. The lattice parameters of the σ phase and the M{sub 23}C{sub 6} carbides observed in this 18%Cr ODS steel aged at 600 °C during 5000 h are measured.

Corrosion rate of steel embedded in blended Portland and fluid catalytic cracking catalyst residue (FC3R cement mortars

Directory of Open Access Journals (Sweden)

Payá, J.

2008-12-01

Full Text Available This paper reports on a study of the corrosion levels in steel bars embedded in mortars made with a blend of Portland cement and (0-20% spent fluid catalytic cracking catalyst residue (FC3R, with a variable (0.3-0.7 water/binder (w/b ratio. The specimens were stored in the following conditions: relative humidity of 40, 80 or 100% and CO2 concentrations of 5 and 100%. The steel corrosion rate was measured with polarization resistance techniques. In the absence of aggressive agents, the steel was found to remain duly passivated in mortars with an FC3R content of up to 15% under all the conditions of relative humidity tested. The reinforcement corrosion level in mortars with a w/b ratio of 0.3 and 15% FC3R subjected to accelerated carbonation was similar to the level observed in the unblended Portland cement control mortar.En este trabajo se ha estudiado el nivel de corrosión de barras de acero embebidas en morteros de cemento Portland con relación agua/material cementante (a/mc variable (0,3-0,7, en los que parte del cemento (0-20% se sustituyó por catalizador de craqueo usado (FC3R. Las condiciones de conservación de las probetas elaboradas fueron las siguientes: distintas humedades relativas (40, 80 y 100% y dos concentraciones de CO2 (5 y 100%. La velocidad de corrosión de los aceros se midió mediante la técnica de resistencia de polarización. Se ha podido determinar que, bajo las distintas condiciones de humedad relativa y ausencia de agresivo, los aceros se mantuvieron correctamente pasivados en los morteros con contenidos de FC3R de hasta el 15%. El nivel de corrosión que presenta el refuerzo embebidos en morteros con sustitución de un 15% de cemento por FC3R y relación a/mc 0,3, al ser sometidos a un proceso de carbonatación acelerada, era muy similar al mostrado por el mortero patrón, sin FC3R.

Behavior of partially defected R.C columns strengthened using steel jackets

Directory of Open Access Journals (Sweden)

Ahmed Shaban Abdel-Hay

2015-08-01

The main parameters studied were the type of steel jacket used and height of partial strengthened part of column. One of the tested specimens was a control specimen and the other six were partially strengthened with different types of steel jackets such as using 4 steel angles at corners connected with straps, using external ties with different spacings, and using 4 steel plates with different thicknesses welded together and connected to column by anchor bolts. Finally, the experimental results were analyzed and compared with results obtained from finite element analysis using ANSYS program.

Reaction of uranium and plutonium carbides with austenitic steels

International Nuclear Information System (INIS)

Mouchnino, M.

1967-01-01

The reaction of uranium and plutonium carbides with austenitic steels has been studied between 650 and 1050 deg. C using UC, steel and (UPu)C, steel diffusion couples. The steels are of the type CN 18.10 with or without addition of molybdenum. The carbides used are hyper-stoichiometric. Tests were also carried out with UCTi, UCMo, UPuCTi and UPuCMo. Up to 800 deg. C no marked diffusion of carbon into stainless steel is observed. Between 800 and 900 deg. C the carbon produced by the decomposition of the higher carbides diffuses into the steel. Above 900 deg. C, decomposition of the monocarbide occurs according to a reaction which can be written schematically as: (U,PuC) + (Fe,Ni,Cr) → (U,Pu) Fe 2 + Cr 23 C 6 . Above 950 deg. C the behaviour of UPuCMo and that of the titanium (CN 18.12) and nickel (NC 38. 18) steels is observed to be very satisfactory. (author) [fr

Corrosion mechanism of Z3 CN18.10 stainless steel in the presence of nitric acid condensates

International Nuclear Information System (INIS)

Balbaud, Fanny

1998-01-01

In installations handling concentrated boiling nitric acid, a severe intergranular corrosion can sometimes occur in condensation zones constituted of non-sensitized Z3 CN 18.10 stainless steel. Corrosion tests in reactors and in a specific loop, CIRCE, allowed to specify the conditions of occurrence of this type of corrosion and showed the similitude with the corrosion in non-renewed liquid nitric acid: the specific parameters linked to the condensate phase are the high ratio metallic surface area to volume of condensate and the low renewing rate which induce a concentration of oxidation products of the metal and of reduction products of nitric acid. The initiation of the intergranular corrosion is attributed to the increase in the reduction rate of nitric acid by an autocatalytic mechanism which was demonstrated by electrochemical measurements on platinum and on stainless steel. The reduction mechanism involves a charge transfer step where nitrous acid, the electro-active species, is reduced into nitrogen monoxide and a chemical regeneration reaction of nitrous acid. The thermodynamic study led to a representation of the chemical and electrochemical properties of nitric acid. This study allowed also to determine the Gibbs free energy of formation of nitrous acid in solution in concentrated nitric acid at 100 deg. C. The diagram, constructed in coordinates log(P O 2 ) / [-log(P HNO 3 )] or E eXperimental / [-log(P HNO 3 )], shows that the final reduction product of nitric acid depends on the concentration of nitric acid: at 100 deg. C, NO is obtained for concentrations lower than 8 mol.L -1 and NO 2 is obtained for higher concentrations. All these results allowed to propose a corrosion mechanism of Z3 CN 18.10 stainless steel in the presence of nitric acid condensates. [fr

Evaluating response modification factor (R for some types of steel structure

Directory of Open Access Journals (Sweden)

Doralba Valencia Restrepo

2008-01-01

Full Text Available Response modification factor (R, tabulated in the Colombian Design Code as NSR-98, is used in this paper for eva-luating internal member forces produced by design earthquake action on steel structures and the inconsistencies pre-sent when designing structures when 1% drift limits must be complied with. The article presents the design of 45 frames corresponding to the seismic resistance system of 5 buildings: 15 special moment frames (SMF, 15 special concentrically-braced frames (CBF and 15 eccentrically-braced frames (EBF. External loads and their combination were used in estimating internal loads and rigidity demands (1% drift were evaluated in line with NSR-98 requi-rements. Member strength requirements were evaluated by using the AISC-2005 seismic provisions for steel structu-red buildings. Modal pushover analysis was used for evaluating the response modification factor for the 45 given frames at different structural performance levels. It was found that this factor was not constant for any of the three structural systems (SMF, CBF and EBF suggested by NSR-98 and that the values of the response modification factor found in the present investigation were smaller than those tabulated in this design code governing everyday structural design. This would lead to significant errors being made in evaluating design forces, not only in the structures but in the support elements (base-plates, foundations, shear walls and any structures attached to buildings constructed in line with the seismic resistance system.

IL18 and IL18R1 polymorphisms, lung CT and fibrosis: a longitudinal study in coal miners

Energy Technology Data Exchange (ETDEWEB)

Nadif, R.; Mintz, M.; Marzec, J.; Jedlicka, A.; Kauffmann, F.; Kleeberger, S.R. [INSERM, U780, Villejuif (France)

2006-12-15

It has been suggested that interleukin (IL)-18 plays a role in the development of inflammatory and fibrosing lung diseases. Associations of polymorphisms in the genes coding for IL-18 (108 /G-656T, C-607A, G-137C, T113G, C127T) and its receptor (IL8R1/C-69T) with coal workers' pneumoconiosis (CWP) were studied in 200 miners who were examined in 1990, 1994 and 1999. Coal-dust exposure was assessed according to job history and ambient measures. The main health outcome was lung computed tomography (CT) score in 1990. Internal coherence was assessed by studying CT score in 1994, 4-yr change in CT score and CWP incidence and prevalence. CT score in 1990 was a good predictor of radiographic grade in 1999 and, therefore, an appropriate subclinical quantitative trait. The IL18 -137C allele was associated with lower CT score in 1990 and 1994 (11.24 versus 1.69 and 1.57 versus 2.46, respectively), slower progression of CT score between 1990 and 1994 and lower pneumoconiosis prevalence in 1999 relative to the G allele (0.33 versus 0.77 and 8.2 versus 19.6%, respectively). Smoking- or dust-adjustment, and stratification on IL18R1 genotype and adjustment for haplotype effects did not change the conclusions. In conclusion, the results of the present study suggest a role for IL18 in reducing the development of this fibrosing lung disease.

Stress corrosion (Astm G30-90 standard) in 08x18H10T stainless steel of nuclear fuel storage pool in WWER reactors

International Nuclear Information System (INIS)

Herrera, V.; Zamora R, L.

1997-01-01

At the water storage of the irradiated nuclear fuel has been an important factor in its management. The actual pools have its walls covered with inoxidable steel and heat exchangers to dissipate the residual heat from fuel. It is essential to control the water purity to eliminate those conditions which aid to the corrosion process in fuel and at related components. The steel used in this research was obtained from an austenitic inoxidizable steel standardized with titanium 08x18H10T (Type 321) similar to one of the two steel coatings used to cover walls and the pools floor. the test consisted in the specimen deformation through an U ply according to the Astm G30-90 standard. The exposition of the deformed specimen it was realized in simulated conditions to the chemical regime used in pools. (Author)

Experimental investigation of the influence of the bond conditions on the shear bond strength between steel and self- compacting concrete using push-out tests

Czech Academy of Sciences Publication Activity Database

Helincks, P.; De Corte, W.; Klusák, Jan; Boel, V.; De Schutter, D.

525-526, č. 1 (2013), s. 205-208 ISSN 1013-9826. [Fracture and Damage Mechanics /11./. Xi'an, 18.09.2012-21.09.2012] R&D Projects: GA ČR GAP108/10/2049; GA ČR(CZ) GAP105/11/1551 Institutional support: RVO:68081723 Keywords : steel-concrete joint * epoxy adhesive layer * push-out test Subject RIV: JL - Materials Fatigue, Friction Mechanics

Highly divergent 18S rRNA gene paralogs in a Cryptosporidium genotype from eastern chipmunks (Tamias striatus)

Czech Academy of Sciences Publication Activity Database

Stenger, B.L.S.; Clark, M.E.; Kváč, Martin; Khan, E.; Giddings, C.W.; Dyer, N.W.; Schultz, J.L.; McEvoy, J.M.

2015-01-01

Roč. 32, JUN 2015 (2015), s. 113-123 ISSN 1567-1348 R&D Projects: GA MŠk(CZ) LH11061 Institutional support: RVO:60077344 Keywords : Cryptosporidium * Paralogy * 18S rRNA * 18S rDNA Subject RIV: GJ - Animal Vermins ; Diseases, Veterinary Medicine Impact factor: 2.591, year: 2015

Divergent nuclear 18S rDNA paralogs in a turkey coccidium, Eimeria meleagrimitis, complicate molecular systematics and identification.

Science.gov (United States)

El-Sherry, Shiem; Ogedengbe, Mosun E; Hafeez, Mian A; Barta, John R

2013-07-01

Multiple 18S rDNA sequences were obtained from two single-oocyst-derived lines of each of Eimeria meleagrimitis and Eimeria adenoeides. After analysing the 15 new 18S rDNA sequences from two lines of E. meleagrimitis and 17 new sequences from two lines of E. adenoeides, there were clear indications that divergent, paralogous 18S rDNA copies existed within the nuclear genome of E. meleagrimitis. In contrast, mitochondrial cytochrome c oxidase subunit I (COI) partial sequences from all lines of a particular Eimeria sp. were identical and, in phylogenetic analyses, COI sequences clustered unambiguously in monophyletic and highly-supported clades specific to individual Eimeria sp. Phylogenetic analysis of the new 18S rDNA sequences from E. meleagrimitis showed that they formed two distinct clades: Type A with four new sequences; and Type B with nine new sequences; both Types A and B sequences were obtained from each of the single-oocyst-derived lines of E. meleagrimitis. Together these rDNA types formed a well-supported E. meleagrimitis clade. Types A and B 18S rDNA sequences from E. meleagrimitis had a mean sequence identity of only 97.4% whereas mean sequence identity within types was 99.1-99.3%. The observed intraspecific sequence divergence among E. meleagrimitis 18S rDNA sequence types was even higher (approximately 2.6%) than the interspecific sequence divergence present between some well-recognized species such as Eimeria tenella and Eimeria necatrix (1.1%). Our observations suggest that, unlike COI sequences, 18S rDNA sequences are not reliable molecular markers to be used alone for species identification with coccidia, although 18S rDNA sequences have clear utility for phylogenetic reconstruction of apicomplexan parasites at the genus and higher taxonomic ranks. Copyright © 2013. Published by Elsevier Ltd.

Anticonvulsant and reproductive toxicological studies of the imidazole-based histamine H3R antagonist 2-18 in mice

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Bastaki SM

2018-01-01

Full Text Available Salim M Bastaki,1 Yousef M Abdulrazzaq,2 Mohamed Shafiullah,1 Małgorzata Więcek,3 Katarzyna Kieć-Kononowicz,3 Bassem Sadek1 1Department of Pharmacology and Therapeutics, College of Medicine and Health Science, United Arab Emirates University, Al Ain, 2Department of Medical Education, Dubai Health Authority, Dubai, UAE; 3Department of Technology and Biotechnology of Drugs, Faculty of Pharmacy, Jagiellonian University Medical College, Medyczna, Kraków, Poland Abstract: The imidazole-based H3R antagonist 2-18 with high in vitro H3R antagonist affinity, excellent in vitro selectivity profile, and high in vivo H3R antagonist potency was tested for its anticonvulsant effect in maximal electroshock (MES-induced convulsions in mice having valproic acid (VPA as a reference antiepileptic drug (AED. Additionally, H3R antagonist 2-18 was evaluated for its reproductive toxicity in the same animal species. The results show that acute systemic administration (intraperitoneal; i.p. of H3R antagonist 2-18 (7.5, 15, 30, and 60 mg/kg, i.p. significantly and dose dependently protected male as well as female mice against MES-induced convulsion. The protective action observed for H3R antagonist 2-18 in both mice sexes was comparable to that of VPA and was reversed when mice were pretreated with the selective H3R agonist (R-alpha-methylhistamine (RAMH, 10 mg/kg, i.p.. Moreover, the results show that acute systemic administration of single (7.5, 15, 30, or 60 mg/kg, i.p. or multiple doses (15×3 mg/kg, i.p. of H3R antagonist 2-18 on gestation day (GD 8 or 13 did not affect the maternal body weight of mice when compared with the control group. Furthermore, no significant differences were observed in the average number of implantations and resorptions between the control and H3R antagonist 2-18-treated group at the early stages of gestation and the organogenesis period. However, oral treatment with H3R antagonist 2-18 (15 mg/kg on GD 8 induced a reduced number of

Random cyclic constitutive models of 0Cr18Ni10Ti pipe steel

International Nuclear Information System (INIS)

Zhao Yongxiang; Yang Bing

2004-01-01

Experimental study is performed on the random cyclic constitutive relations of a new pipe stainless steel, 0Cr18Ni10Ti, by an incremental strain-controlled fatigue test. In the test, it is verified that the random cyclic constitutive relations, like the wide recognized random cyclic strain-life relations, is an intrinsic fatigue phenomenon of engineering materials. Extrapolating the previous work by Zhao et al, probability-based constitutive models are constructed, respectively, on the bases of Ramberg-Osgood equation and its modified form. Scattering regularity and amount of the test data are taken into account. The models consist of the survival probability-strain-life curves, the confidence strain-life curves, and the survival probability-confidence-strain-life curves. Availability and feasibility of the models have been indicated by analysis of the present test data

Effect of smelt aluminium on mechanical properties of steels

International Nuclear Information System (INIS)

Ryabov, V.R.; Dykhno, I.S.; Deev, G.F.; Karikh, V.V.

1987-01-01

Effect of smelt aluminium on mechanical properties of armco-iron and 12 Kh18N10T steel is studied. It is stated that in smelt aluminium and aluminium alloy contact with armco-iron the sample ductility is decreased. Corrosion effect of smelt alluminium on (18Kh15N5AM3) steel in the form of reinforced wire in aluminium-steel KAS-1A composite material is investigted. It is stated in experiment that during smelt alluminium-steel contact interaction of heterogeneous phases takes place

Mel-18 negatively regulates stem cell-like properties through downregulation of miR-21 in gastric cancer.

Science.gov (United States)

Wang, Xiao-Feng; Zhang, Xiao-Wei; Hua, Rui-Xi; Du, Yi-Qun; Huang, Ming-Zhu; Liu, Yong; Cheng, Yu Fang; Guo, Wei-Jian

2016-09-27

Mel-18, a polycomb group protein, has been reported to act as a tumor suppressor and be down-regulated in several human cancers including gastric cancer. It was also found that Mel-18 negatively regulates self-renewal of hematopoietic stem cells and breast cancer stem cells (CSCs). This study aimed to clarify its role in gastric CSCs and explore the mechanisms. We found that low-expression of Mel-18 was correlated with poor prognosis and negatively correlated with overexpression of stem cell markers Oct4, Sox2, and Gli1 in 101 gastric cancer tissues. Mel-18 was down-regulated in cultured spheroid cells, which possess CSCs, and overexpression of Mel-18 inhibits cells sphere-forming ability and tumor growth in vivo. Besides, Mel-18 was lower-expressed in ovary metastatic lesions compared with that in primary lesions of gastric cancer, and Mel-18 overexpression inhibited the migration ability of gastric cancer cells. Interestingly, overexpression of Mel-18 resulted in down-regulation of miR-21 in gastric cancer cells and the expression of Mel-18 was negatively correlated with the expression of miR-21 in gastric cancer tissues. Furthermore, miR-21 overexpression partially restored sphere-forming ability, migration potential and chemo-resistance in Mel-18 overexpressing gastric cancer cells. These results suggests Mel-18 negatively regulates stem cell-like properties through downregulation of miR-21 in gastric cancer cells.

A unified model of the strong and electroweak interactions based on the gauge group SU(18)L x SU(18)R

International Nuclear Information System (INIS)

Kim Il Kang

1986-01-01

On the basis of semi-simple gauge group G=SU(18) L x SU(18) R the unified theory of strong, weak and electromagnetic fields is constructed, and it is shown that the Weinberg angle and the energy of unification are in good agreement with the experimental values. (author)

Effect of agressive medium movement of local corrosion of the steel - 12Kh18N10T

International Nuclear Information System (INIS)

Makartsev, V.V.; Pakhomov, V.S.; Abramova, I.M.

1980-01-01

The effect of agressive medium movement on the formation of pitting corrosion of the 12Kh18N10T stainless steel in the acidic chloride-nitrate solution at room temperature is studied. It is established that the agressive medium movement hinders the formation of pitting corrosion at potentials more negative than +0.4 V and practically does not affect it at more positive potentials. The investigations have been carried out on a disc electrode rotating at a speed from 0 to 2000 rot./min

(1R,6R,13R,18R-(Z,Z-1,18-Bis[(4R-2,2-dimethyl-1,3-dioxolan-4-yl]-3,16-dimethylene-8,20-diazadispiro[5.6.5.6]tetracosa-7,19-diene

Directory of Open Access Journals (Sweden)

Stéphanie M. Guéret

2010-07-01

Full Text Available The crystal structure of the title compound, C34H54N2O4, has been solved in order to prove the relative and absolute chirality of the newly-formed stereocentres which were established using an asymmetric Diels–Alder reaction at an earlier stage in the synthesis. This unprecedented stable dialdimine contains a 14-membered ring and was obtained as the minor diastereoisomer in the Diels–Alder reaction. The absolute stereochemistry of the stereocentres of the acetal functionality was known to be R based on the use of a chiral (R-trisubstituted dienophile derived from enantiopure (S-glyceraldehyde. The assignment of the configuration in the dienophile and the title di-aldimine differs from (S-glyceraldehyde due to a change in the priority order of the substituents. The crystal structure establishes the presence of six stereocentres all attributed to be R. The 14-membered ring contains two aldimine bonds [C—N = 1.258 (2 and 1.259 (2 Å]. It adopts a similar conformation to that proposed for trans–trans-cyclotetradeca-1,8-dienes.

[Factors influencing electrocardiogram results in workers exposed to noise in steel-making and steel-rolling workshops of an iron and steel plant].

Science.gov (United States)

Li, Y H; Yu, S F; Gu, G Z; Chen, G S; Zhou, W H; Wu, H; Jiao, J

2016-02-20

To investigate the factors influencing the electrocardiogram results in the workers exposed to noise in steel-making and steel rolling workshops of an iron and steel plant. From September to December, 2013, cluster sampling was used to select 3 150 workers exposed to noise in the steel-making and steel-rolling workshops of an iron and steel plant, and a questionnaire survey and physical examinations were performed. The number of valid workers was 2 915, consisting of 1 606 workers in the steel-rolling workshop and 1 309 in the steel-making workshop. The electrocardiogram results of the workers in steel-making and steel-rolling workshops were analyzed. The overall abnormal rate of electrocardiogram was 26.35%, and the workers in the steel-making workshop had a significantly higher abnormal rate of electrocardiogram than those in the steel-rolling workshop(32.24% vs 21.54%, Pelectrocardiogram than female workers(27.59% vs 18.61%, Pelectrocardiogram than those who did not drink(28.17% vs 23.75%, Pelectrocardiogram than those who were not exposed to high temperature(29.43% vs 20.14%, Pelectrocardiogram in the workers with cumulative noise exposure levels of electrocardiogram results. High cumulative noise exposure, alcohol consumption, and high temperature may affect the abnormal rate of electrocardiogram in the workers exposed to noise in steel-making and steel-rolling workshops.

Experimental investigation of heat transfer of R134a in pool boiling on stainless steel and aluminum tubes

Science.gov (United States)

Wengler, C.; Addy, J.; Luke, A.

2018-03-01

Due to high energy demand required for chemical processes, refrigeration and process industries the increase of efficiency and performance of thermal systems especially evaporators is indispensable. One of the possibilities to meet this purpose are investigations in enhancement of the heat transfer in nucleate boiling where high heat fluxes at low superheat are transferred. In the present work, the heat transfer in pool boiling is investigated with pure R134a over wide ranges of reduced pressures and heat fluxes. The heating materials of the test tubes are aluminum and stainless steel. The influence of the thermal conductivity on the heat transfer coefficients is analysed by the surface roughness of sandblasted surfaces. The heat transfer coefficient increases with increasing thermal conductivity, surface roughness and reduced pressures. The experimental results show a small degradation of the heat transfer coefficients between the two heating materials aluminum and stainless steel. In correlation with the VDI Heat Atlas, the experimental results are matching well with the predictions but do not accurately consider the stainless steel material reference properties.

Familial ring (18) mosaicism in a 23-year-old young adult with 46,XY,r(18) (::p11→q21::)/46,XY karyotype, intellectual disability, motor retardation and single maxillary incisor and in his phenotypically normal mother, karyotype 47,XX,+r(18)(::p11→q21::)/46,XX.

Science.gov (United States)

Balci, Sevim; Tümer, Celal; Karaca, Ciğdem; Bartsch, Oliver

2011-05-01

We report on a 23-year-old man with craniofacial findings of the holoprosencephaly spectrum disorder (microcephaly, hypotelorism, depressed nasal bridge, single median maxillary central incisor), fusion of C2-C3 vertebrae, intellectual disability, and severe sleep apnea. Chromosome analysis of blood lymphocytes showed 75% ring (18) cells and 25% normal cells, karyotype mos 46,XY,r(18)(::p11→q21::)[75]/46,XY[25]. His mother was phenotypically normal except for a double ureter and bifid renal pelvis as in his son. She had a supernumerary ring (18) in 10% of blood lymphocytes, karyotype mos 47,XX,+r(18)(::p11→q21::)[10]/46,XX[90]. Familial ring (18) is a rare cytogenetic abnormality. This is the first report of a mother with a supernumerary ring (18) and a son with ring (18) mosaicism. Interestingly, the son showed a true mosaicism (mixoploidy) of ring (18) and normal cells. The mother's 46,XX cells could be easily explained by mitotic instability and ring loss during cell division. However, the coexistence of ring (18) and normal cells in the son is unusual. Possibly, during early postzygotic divisions of a 47,XY,+r(18) zygote, two (possibly subsequent) genetic events could have occurred, one when one normal chromosome 18 was lost (resulting in a cell line with ring 18), and one when the ring 18 was lost (resulting in a cell line without ring, "escape to normal"). Alternatively, the zygote of the son could have been 46,XY,r(18), and postzygotic loss of the ring 18 could have resulted in monosomy 18 cells followed by duplication of chromosome 18 in these cells (a rare mechanism for cell survival previously described as "compensatory" isodisomy). Copyright © 2011 Wiley-Liss, Inc.

Enhancement of tribological properties of 9Cr18 stainless steel by dual Mo and S Co implantation

International Nuclear Information System (INIS)

Zhang Tao; Song Jiaohua; Li Guoqing; Chu, Paul K.; Brown, Ian G.

2001-01-01

Mo and S ions were simultaneously implanted into 9Cr18 stainless steel samples. The frictional properties of the implanted samples were assessed using a pin-on-disk tester and the elemental depth profiles were measured by Auger electron spectroscopy. The hardness of the samples was also measured. We find that this dual-element implantation process reduces the coefficient of friction by a factor of 2 and increases the low-friction lifetime by a factor of 4 compared to the 9Cr18 surface with Mo or S implantation alone. This enhancement is related to the synergistic coexistence of the implanted elements at the same place. We have also investigated the process using computer simulation. The simulation results help disclose the characteristics of the modified layer and explain the effects of dual-element ion implantation

Study of the effect of an increase in phosphorus content on the corrosion resistance of austenitic stainless steels type 18-10

International Nuclear Information System (INIS)

Charbonnier, J.C.; Thomas, B.

1982-01-01

The work is carried out on Z 6 CN 18-10 steels with P concentrations in the range of 0.004 to 0.127%, to examine intercrystalline corrosion, pitting corrosion and cavern corrosion. It is concluded that a slight increase in the P content above 0.04% is compatible with an acceptable corrosion behaviour [fr

Molecular technique reveals high variability of 18S rDNA distribution in harvestmen (Opiliones, Phalangiidae) from South Africa.

Science.gov (United States)

Šťáhlavský, František; Opatova, Vera; Just, Pavel; Lotz, Leon N; Haddad, Charles R

2018-01-01

The knowledge of cytogenetics in the harvestmen family Phalangiidae has been based on taxa from the Northern Hemisphere. We performed cytogenetic analysis on Guruia africana (Karsch, 1878) (2n=24) and four species of the genus Rhampsinitus Simon, 1879 (2n=24, 26, 34) from South Africa. Fluorescence in situ hybridization with an 18S rDNA probe was used to analyze the number and the distribution of this cluster in the family Phalangiidae for the first time. The results support the cytogenetic characteristics typical for the majority of harvestmen taxa, i.e. the predominance of small biarmed chromosomes and the absence of morphologically well-differentiated sex chromosomes as an ancestral state. We identified the number of 18S rDNA sites ranging from two in R. qachasneki Kauri, 1962 to seven in one population of R. leighi Pocock, 1903. Moreover, we found differences in the number and localization of 18S rDNA sites in R. leighi between populations from two localities and between sexes of R. capensis (Loman, 1898). The heterozygous states of the 18S rDNA sites in these species may indicate the presence of XX/XY and ZZ/ZW sex chromosomes, and the possible existence of these systems in harvestmen is discussed. The variability of the 18S rDNA sites indicates intensive chromosomal changes during the differentiation of the karyotypes, which is in contrast to the usual uniformity in chromosomal morphology known from harvestmen so far.

Influence of stainless steel Internals on Corrosion of tower wall materials

Science.gov (United States)

Chen, Bing; Ren, Ke

2017-12-01

In view of the galvanic corrosion of the tower wall material in the tower of a refinery atmospheric vacuum distillation unit, the electrochemical behavior of Q345R steel, stainless steel (201, 304 cold-rolled plate, 304 hot rolled plate and 316L) in 3.5%NaCl solution was studied by electrochemical method. The results show that the corrosion potential of Q345R is much lower than that of stainless steel, and the corrosion rate of Q345R is higher than that of stainless steel. As the anode is etched as the anode corrosion, the anode polarizability of stainless steel shows strong polarization ability, which is anodic polarization control, and Q345R is anode Active polarization control; Q345R / 201 galvanic pair may be the most serious corrosion, and Q345R/316L galvanic couple may be relatively slight. Therefore, in the actual production of tower equipment, material design or tower to upgrade the replacement, it are recommended to use the preferred anode and cathode potential difference with the use of materials.

Analysis of the Behaviour of Composite Steel and Steel Fiber Reinforced Concrete Slabs

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Mindaugas Petkevičius

2011-04-01

Full Text Available There was a pending influence of steel fiber on the strength and stiffness of composite steel–concrete slabs under statical short–time load. Steel profiled sheeting and steel fiber reinforced concrete were used for specimens. Four composite slabs were made. Experimental investigations into the behaviour and influence of steel fiber reinforced concrete in composite slabs were conducted. Transverse, longitudinal, shear deformation and deflection of the slab were measured. The results indicated that the use of steel fiber in composite slabs was effective: strength was 20–24 % higher and the meanings of deflections under the action of the bending moment were 0,6MR (where MR is the bending moment at failure of the slabs and were 16–18 % lower for slabs with usual concrete. Article in Lithuanian

Effect of shot peening on the residual stress and mechanical behaviour of low-temperature and high-temperature annealed martensitic gear steel 18CrNiMo7-6

DEFF Research Database (Denmark)

Yang, R.; Zhang, X.; Mallipeddi, D.

2017-01-01

A martensitic gear steel (18CrNiMo7-6) was annealed at 180 degrees C for 2h and at similar to 750 degrees C for 1h to design two different starting microstructures for shot peening. One maintains the original as-transformed martensite while the other contains irregular-shaped sorbite together...... with ferrite. These two materials were shot peened using two different peening conditions. The softer sorbite + ferrite microstructure was shot peened using 0.6 mm conditioned cut steel shots at an average speed of 25 m/s in a conventional shot peening machine, while the harder tempered martensite steel...

Kinetics of phase transformations of undercooled austenite in 18CrNiMo7-6 steel applied for toothed wheels

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J. Krawczyk

2010-07-01

Full Text Available Toothed wheels constitute essential part of the steel structural elements market. The most often hypereutectoid structural steels forcarburizing are used for toothed wheels. The final producers of toothed wheels are not demanding regarding a microstructure, providedthat the determined requirements will be fulfilled (e.g. metallurgical purity determined by ultrasounds. Therefore delivered forgings can be in an annealed or quenched state. This results from the situation that the final heat treatment or heat-chemical one is being done at one of the last stages of the toothed wheel production. An essential factor allowing to develop the proper heat treatment is the knowledge of the kinetics of phase transformations of undercooled austenite and its relating to technological conditions, being at the producer disposal, as well as to forging dimensions. Such investigations should be carried out on real melts used for forgings for toothed wheels production together with an analysis of microstructure changes on the forging cross-section. They should be based on calculation methods determining the distribution of cooling rates on its cross-section in dependence of an applied cooling medium.The mentioned above problems in relation to 18CrNiMo7-6 steel - are elucidated in this paper. The aim of the investigations wasthe description of the kinetics of phase transformations of undercooled austenite in this steel. The CCT diagram was constructed for the austenitizing temperature determined on the basis of phase transformations temperatures (the so-called critical points.

Additional materials for welding of the EP99 heat resisting alloy with the EI868 alloy and 12Kh18N9T steel

International Nuclear Information System (INIS)

Sorokin, L.I.; Filippova, S.P.; Petrova, L.A.

1978-01-01

Presented are the results of the studies aimed at selecting an additive material for argon-arc welding process involving heat-resistant nickel EP99 alloy to be welded to the EI868 alloy and 12Kh18N9T steel. As the additive material use was made of wire made of nickel-chromium alloys and covered electrodes made of the EP367 alloy with additions of tungsten. It has been established that in order to improve the resistance of metal to hot-crack formation during argon arc welding of the EP99 alloy with the EI868 alloy, it is advisable to use an additive material of the EP533 alloy, and while welding the same alloy with the 12Kh18N9T steel, filler wire of the EP367 alloy is recommended

Effect of partial oxygen pressure on physicochemical properties of Kh18N10T steel at isothermal oxidation. Vliyanie partsial'nogo davleniya kisloroda na fiziko-khimicheskie svojstva poverkhnosti stali Kh18N10T pri izotermicheskom okislenii

Energy Technology Data Exchange (ETDEWEB)

Alekseev, V N; Oshe, E K; Fokin, M N; Bogdanova, S V; Loskutov, A I [AN SSSR, Moscow (USSR). Inst. Fizicheskoj Khimii

1990-10-01

Auger-electron spectroscopy, photoelectric polarization, conductometry methods have been used to analyze chemical and defect composition of surface oxide layers, formed on stainless steel Kh18N10T in vacuum (10{sup -9} - 10{sup -2} torr) and at temperatures 593-673 K. The boundary conditions of manifestation of extermal behaviour of the dependence of the surface oxide growth rate at isothermal oxidation of this steel are determined. The relation between passivation properties of the surface oxide and the magnitude of the edge angle of the surface wetting with molten tin is revealed.

On the corrosion resistance of 01Kh25 ferritic steel

International Nuclear Information System (INIS)

Eremeeva, R.A.; Koval', E.K.

1989-01-01

Effect of non-ferrous metal ions on corrosion behaviour of 01Kh25 specific low carbon steel as compared to austenitic 12Kh18N10T and 06KhN28MDT steels in boiling solutions of sulfuric and nitric acids and their mixture is studied. Compositions initating commercial ones are chosen the media. It is shown that trough corrosion resistance of 01Kh25 steel in 10% H 2 SO 4 is two order below 06KhN28MDT austenitic steel in presence of Cu 2+ ions as a result of the surface passivation corrosion resistance of ferritic steel is an order higher the austenitic ones. Ferrite steel resistance in the nitric acid and its mixture with sulfuric acid is five timesas much as in 12Kh18N10T austenitic steel

Formed electroslag welded joint from austenitic steel 18/10 CrNi

International Nuclear Information System (INIS)

Jilek, L.; Kusak, L.; Martinak, A.

1987-01-01

The electroslag welded joint from titanium stabilized steel 18/10 CrNi of 150 mm in thickness showed positive results for both nondestructive and destructive testing. Czechoslovak flux VUZ-4F and the optimized welding mode were completely proven. The weldment was subject to deformation by forging with a removal of 20 to 50% and to bending deformation. A 40% to 50% deformation was necessary for breaking the coarse-grain casting structure. The bending deformation resulted in breaking the coarse-grain casting structure in the entire cross-section, it was, however, only acting in a narrow band corresponding to the largest curvature. At the same time, the heat affected zone decayed. Following heat treatment, especially forming, the delta ferrite content in the weld metal decreased, the mechanical properties of the weld metal and the welded joint following welding and heat treatment showed a relatively large scatter. Forming reduced the scatter and improved plastic properties. Machining within 40 and 50% resulted in good echogenicity of the welded joint in ultrasound testing. The welded joint showed equal properties as the base material of the weldment. (author). 15 figs., 2 tabs., 16 refs

Effect of 4-(N,N-diethylamino)benzaldehyde thiosemicarbazone on the corrosion of aged 18 Ni 250 grade maraging steel in phosphoric acid solution

International Nuclear Information System (INIS)

Poornima, T.; Nayak, Jagannath; Nityananda Shetty, A.

2011-01-01

Highlights: → DEABT as corrosion inhibitor for maraging steel in phosphoric acid. → Inhibition efficiency increases with increase in inhibitor concentration. → Inhibition efficiency decreases with increase in temperature. → Adsorption obeys Langmuir adsorption isotherm. - Abstract: 4-(N,N-diethylamino)benzaldehyde thiosemicarbazone (DEABT) was studied for its corrosion inhibition property on the corrosion of aged 18 Ni 250 grade maraging steel in 0.67 M phosphoric acid at 30-50 deg. C by potentiodynamic polarization, EIS and weight loss techniques. Inhibition efficiency of DEABT was found to increase with the increase in DEABT concentration and decrease with the increase in temperature. The activation energy E a and other thermodynamic parameters (ΔG ads 0 , ΔH ads 0 , ΔS ads 0 ) have been evaluated and discussed. The adsorption of DEABT on aged maraging steel surface obeys the Langmuir adsorption isotherm model and the inhibitor showed mixed type inhibition behavior.

Recent progress in reduced activation ferritic steels R and D in Japan

International Nuclear Information System (INIS)

Kimura, A.; Kohyama, A.; Sawai, T.; Shiba, K.; Hishinuma, A.; Jitsukawa, S.; Ukai, S.

2003-01-01

The Japanese RAFSs R and D road map toward DEMO is shown. Important steps include high-dose irradiation by fission reactors, such as HFIR in ORNL, irradiation tests by 14 MeV neutrons in IFMIF and application to ITER test blanket modules to provide an adequate database of RAFS for the design of DEMO. Current status of RAFS development is also introduced. The major properties of concern are well within our knowledge and process technologies are mostly ready for fusion application. The RAFSs are now certainly ready to proceed to the next stage. Material database is already in hand and further progress is anticipated for the design of ITER test blanket. Oxide Dispersion strengthening (ODS) steels are quite promising for high temperature operation of the blanket system with potential improvements in radiation resistance of mechanical performances and of corrosion. (author)

Comparative assessment of cyclic J-R curve determination by different methods in a pressure vessel steel

Energy Technology Data Exchange (ETDEWEB)

Chowdhury, Tamshuk, E-mail: tamshuk@gmail.com [Deep Sea Technologies, National Institute of Ocean Technology, Chennai, 600100 (India); Sivaprasad, S.; Bar, H.N.; Tarafder, S. [Fatigue & Fracture Group, Materials Science and Technology Division, CSIR-National Metallurgical Laboratory, Jamshedpur, 831007 (India); Bandyopadhyay, N.R. [School of Materials Science and Engineering, Indian Institute of Engineering, Science and Technology, Shibpur, Howrah, 711103 (India)

2016-04-15

Cyclic J-R behaviour of a reactor pressure vessel steel using different methods available in literature has been examined to identify the best suitable method for cyclic fracture problems. Crack opening point was determined by moving average method. The η factor was experimentally determined for cyclic loading conditions and found to be similar to that of ASTM value. Analyses showed that adopting a procedure analogous to the ASTM standard for monotonic fracture is reasonable for cyclic fracture problems, and makes the comparison to monotonic fracture results straightforward. - Highlights: • Different methods of cyclic J-R evaluation compared. • A moving average method for closure point proposed. • η factor for cyclic J experimentally validated. • Method 1 is easier, provides a lower bound and direct comparison to monotonic fracture.

Formation of non-equilibrium structures in R6M5 steel under strong pulse beams action

International Nuclear Information System (INIS)

Rusin, Yu.G.; Plotnikov, S.V.

2001-01-01

Formation of non-equilibrium structures in R6M5 steel surface layer in the supply state under irradiation by strong pulse beams (SPB) is examined. Cylindric samples with diameter 10 mm and height 15 mm of R6M5 fast-cutting steel with following content (weight %): 0.85% C, 0.4% Mn, 0.5% Si, 4.0 Cr; 2.1% V; 5.3% Mo, 6.0% W; 0.4% Ni, Fe (the rest) were examined. Irradiation by SPB was conducted on the 'TEMP' modified accelerator operating in a technological regime with carbon beams parameters: energy from 0.3 up o 0.4 MeV, beam density in an impulse from 20 to 250 A/cm 2 , pulse duration from 60 tp 100 ns. The beam consists of 70 % carbon ions and 30 % hydrogen ions. Phase identification and its structural phase analysis have been studied on the DRON-3 X-ray diffractometer of common assignment. Topography of metallographic specimen surface has been examined on the REM-200 scanning electron microscope. Doping elements redistribution and phases quantitative characteristics after SPB action were studied with help of the X-ray spectral microanalysis (XRSA) on the MS-46 Camebax microanalyzer. Character of doping elements redistribution in the alloy (XRSA data) show its appreciably redistribution, moreover in the melted zone the increased content of molybdenum, tungsten, vanadium is observing, and in the zone of thermal action its increase relatively to matrix values

Properties of high temperature low cycle fatigue in austenitic stainless steel

International Nuclear Information System (INIS)

Kim, D. H.; Han, C. H.; Ryu, W. S.

2002-01-01

Tensile and fatigue tests were conducted at R. T. and 300 .deg. C for type 304 and 316 stainless steel. Tensile strength and elongation decreased and fatigue life increased with temperature for both type 304 and 316 stainless steel. Dislocation structures were mixed with cell and planar at R. T. and 300 .deg. C for both type 304 and 316 stainless steel. Strain induced martensite of type 316 stainless steel was less than that of type 304 stainless steel and decreased with temperature. It is considered that strain induced martensite is an important factor to increase fatigue life at 300 .deg. C

Inclusion Modification by Al Deoxidation and Ca Treatment in Ti Containing 18%Cr Stainless Steel Melts

International Nuclear Information System (INIS)

Kim, Kyung-Ho; Do, Kyung-Hyo; Choi, Won-Jin; Kim, Dong-Sic; Pak, Jong-Jin; Lee, Sang-Beum

2013-01-01

Titanium is added to ferritic stainless steels in the range of 0.2-0.3 wt% to improve corrosion resistance and mechanical properties. However, titanium is very reactive with oxygen in liquid steel, and it can cause an unstable Ti yield. Therefore, titanium is generally added after the aluminum deoxidation process in the ladle. However, the inclusions formed by Al-Ti deoxidation can cause nozzle clogging and various defects in final products. Calcium injection can be carried out to resolve these problems. In this study, two different deoxidation patterns of Al→Ti and Al→Ti→Ca additions were carried out in Fe-18%Cr ferritic stainless steel melt at 1873 K. The melt composition and the inclusion morphology changes during the deoxidation process were investigated. With Al→Ti addition, the Al_2O_3 inclusions changed to dual phase Al_2O_3-TiO_X inclusions with time by the reaction with Ti in the melt. The morphology of the inclusions in the melt finally changed to a polygonal type indicating that the inclusions were solid phase. The size and number of inclusions in the melt did not change with time after Ti addition. With of Al→Ti→Ca addition, Ca reacted with Al_2O_3-TiO_X inclusions to form liquid CaOAl_2O_3 inclusions embedded with solid CaTiO_3 particles. The morphology of the inclusions in the melt were observed to be spherical and polygonal. The size of inclusions in the melt increased and the number of inclusions decreased by the coalescence of liquid inclusions.

Local corrosion of high alloy steels under biodeposits

International Nuclear Information System (INIS)

Korovyakova, M.D.; Nikitin, V.M.; Speshneva, N.V.

1999-01-01

Impact of the bacteriozenosis different structural-functional state under biodeposits on corrosion resistance of the 12Kh18N10T and Kh18N10T high-alloy steels in the natural seawater is studied. It is shown that saturation of natural micro communities by separate aerobic and facultative-anaerobic bacterial monocultures increases corrosion resistance of these steels by their overgrow with biodeposits [ru

Current status of reduced-activation ferritic/martensitic steels R and D for fusion energy

International Nuclear Information System (INIS)

Kimura, Akihiko

2005-01-01

Reduced-activation ferritic/martensitic (RAF/M) steels have been considered to be the prime candidate for the fusion blanket structural material. The irradiation data obtained up to now indicates rather high feasibility of the steels for application to fusion reactors because of their high resistance to degradation of material performance caused by both the irradiation-induced displacement damage and transmutation helium atoms. The martensitic structure of RAF/M steels consists of a large number of lattice defects before the irradiation, which strongly retards the formation of displacement damage through absorption and annihilation of the point defects generated by irradiation. Transmutation helium can be also trapped at those defects in the martensitic structure so that the growth of helium bubbles at grain boundaries is suppressed. The major properties of the steels are well within our knowledge, and processing technologies are mostly developed for fusion application. RAF/M steels are now certainly ready to proceed to the next stage, that is, the construction of International Thermo-nuclear Experimental Reactor Test Blanket Modules (ITER-TBM). Oxide dispersion strengthening (ODS) steels have been developed for higher thermal efficiency of fusion power plants. Recent irradiation experiments indicated that the steels were quite highly resistant to neutron irradiation embrittlement, showing hardening accompanied by no loss of ductility. High-Cr ODS steels whose chromium concentration was in the range from 14 to 19 mass% showed high resistance to corrosion in supercritical pressurized water. It is shown that the 14Cr-ODS steel is susceptible to neither hydrogen nor helium embrittlement. A combined utilization of ODS steels with RAF/M steels will be effective to realize fusion power early at a reasonable thermal efficiency. (author)

Stainless steels for cryogenic bolts and nuts

International Nuclear Information System (INIS)

Leroy, F.; Rabbe, P.; Odin, G.

1975-01-01

Stainless steel for cryogenic applications are generally austenitic steels which, under the effect of cold-drawing, can or cannot undergo a partial martensitic transformation according to their composition. It has been shown that very high ductility and endurance characteristics at low temperatures, together with very high yield strength and resistances values, can be attained with grades of nitrogenous steels of types Z2CN18-10N and Z3CMN18-8-6N. Optimum ductility values are obtained by employing to the best possible, the martensitic transformations which develop during cold-drawing. From the plotting of the rational traction curves, it is possible to analyse very simply the influence of the composition on the martensitic transformations [fr

Residual stress relief in MAG welded joints of dissimilar steels

International Nuclear Information System (INIS)

Seodek, P.; Brozda, J.; Wang, L.; Withers, P.J.

2003-01-01

This paper addresses the relief of residual stress in welded joints between austenitic and non-alloyed ferritic-pearlitic steels. A series of similar and dissimilar steel joints based on the 18G2A (ferritic-pearlitic) and 1H18N10T (austenitic) steels were produced, some of which were stress relieved by annealing and some by mechanical prestressing. For the as-welded and stress relieved test joints the residual stresses were measured by trepanning. To aid the interpretation of these results, 2D plane stress finite element analysis has been performed to simulate the residual stress relieving methods. Analysis of the results has shown that thermal stress relieving of welded joints between dissimilar steels is not effective and may even increase residual stresses, due to the considerable difference in thermal expansion of the joined steels. It was found that, for the loads imposed, the effectiveness of the mechanical stress relieving of dissimilar steel welded joints was much lower than that of similar steel joints

The creep-rupture behaviour of the martensitic steel X18CrMoVNb 121 (no.1.4914) in liquid Pb-17 Li at 550 and 6000C

International Nuclear Information System (INIS)

Grundmann, M.; Borgstedt, H.U.; Schirra, M.

1988-01-01

One of the candidate structural materials for the NET blanket is the martensitic steel X18 CrMoVNb 12 1 (no.1.4914). Its compatibility with the molten eutectic Pb-17Li, which might be used as liquid breeder and coolant in a self-cooled liquid metal blanket, should be satisfying even under superimposed mechanical stress. The mechanical high-temperature strength of the steel should not be significantly reduced by the interaction with the liquid metal which is in close contact with the surface of the components of such a blanket. The corrosion behaviour of this steel in flowing Pb-17Li eutectic is also studied, results will be presented at this conference. A certain influence of a liquid metal environment on the creep-rupture behaviour of steels was observed earlier in a study on the mechanical properties of austenitic stainless steel in liquid sodium. Therefore, a test programme was initiated to evaluate the effects of liquid Pb-17Li alloy on the creep strength of the steel no. 1.4914. Liquid lithium environment showed an influence on the fracture of this material in short time tests at moderate temperature

Tool life equation for blanking 18-8 stainless steel strips

Directory of Open Access Journals (Sweden)

Faura, F.

1998-08-01

Full Text Available Hereinafter it is presented a model for the behaviour and life of circular blanking tool used in sheet forming processes of 18-8 stainless steel (sheet thickness: 1 mm. Firstly it has analyzed the different studies that have previously delt with this problem. Secondly taking into account recently made experiments, it is proposed a simple formulation to predict tool life with enough reliability. To this purpose it has examined different parameters in the wear process, inferring from these the fundamental parameters that regulate them and about which the different equations have been configurated. Blanking tests were performed using a 20 t press at a speed of 150 strokes/min. Punch materials used in these tests were AISI A2 and AISI D2 with diameters between 1.5 and 10 mm. The blanking tests were performed at a clearance between 5 and 20 % of the work material thickness.

En el presente artículo se presenta un modelo de ecuación de vida de herramientas para punzonado circular de chapa de acero inoxidable 18-8 (1 mm de espesor. Se han analizado inicialmente los diferentes estudios que previamente han abordado este problema. Posteriormente, teniendo en cuenta los experimentos realizados recientemente, se propone una formulación simple para predecir con Habilidad suficiente la vida de la herramienta. Para este propósito se han examinado los diferentes parámetros que afectan al proceso de desgaste, infiriendo a partir de estos, los parámetros fundamentales que lo regulan y sobre los cuales se han configurado las diferentes ecuaciones. Los ensayos fueron realizados en una prensa de 20 t y una velocidad de punzonado de 150 golpes/min. Los materiales de los punzones usados en los ensayos fueron AISI A2 y AISI D2 con diámetros comprendidos entre 1,5 y 10 mm. Los ensayos se realizaron para juegos de corte comprendidos entre un 5 y 20 % del espesor de la chapa.

Steel alloys

International Nuclear Information System (INIS)

Bloom, E.E.; Stiegler, J.O.; Rowcliffe, A.F.; Leitnaker, J.M.

1977-01-01

The invention deals with a fuel element for fast breeder reactors. It consits essentially of a uranium oxide, nitride, or carbide or a mixture of these fuels with a plutonium or thorium oxide, nitride, or carbide. The fuel elements are coated with an austenitic stainless steel alloy. Inside the fuel elements, vacancies or small cavities are produced by neutron effects which causes the steel coating to swell. According to the invention, swelling is prevented by a modification of type 304, 316, 321, or 12 K 72HV commercial steels. They consist mainly of Fe, Cr, and Ni in a ratio determined by a temary diagram. They may also contain 1.8 to 2.3% by weight of Mo and a fraction of Si (0.7 to 2% by weight) and Ti(0.10 to 0.5% by weight) to prevent cavity formation. They are structurally modified by cold working. (IHOE) [de

Evidence that two types of 18S rDNA coexist in the genome of Dugesia (Schmidtea) mediterranea (Platyhelminthes, Turbellaria, Tricladida).

Science.gov (United States)

Carranza, S; Giribet, G; Ribera, C; Baguñà; Riutort, M

1996-07-01

Sequences of 18S ribosomal DNA (rDNA) are increasingly being used to infer phylogenetic relationships among living taxa. Although the 18S rDNA belongs to a multigene family, all its copies are kept homogeneous by concerted evolution (Dover 1982; Hillis and Dixon 1991). To date, there is only one well-characterized exception to this rule, the protozoan Plasmodium (Gunderson et al. 1987; Waters, Syin, and McCutchan 1989; Qari et al. 1994). Here we report the 1st case of 18S rDNA polymorphism within a metazoan species. Two types (I and II) of 18S rDNA have been found and sequenced in the platyhelminth Dugesia (Schmidtea) mediterranea (Turbellaria, Seriata, Tricladida). Southern blot analysis suggested that both types of rDNA are present in the genome of this flatworm. This was confirmed through sequence comparisons and phylogenetic analysis using the neighbor-joining method and bootstrap test. Although secondary structure analysis suggests that both types are functional, only type I seems to be transcribed to RNA, as demonstrated by Northern blot analysis. The finding of different types of 18S rDNAs in a single genome stresses the need for analyzing a large number of clones whenever 18S sequences obtained by PCR amplification and cloning are being used in phylogenetic reconstruction.

Detection and evaluation of embedded mild steel can material into 18 Cr-oxide dispersion strengthened steel tubes by magnetic Barkhausen emission

Science.gov (United States)

Kishore, G. V. K.; Kumar, Anish; Rajkumar, K. V.; Purnachandra Rao, B.; Pramanik, Debabrata; Kapoor, Komal; Jha, Sanjay Kumar

2017-12-01

The paper presents a new methodology for detection and evaluation of mild steel (MS) can material embedded into oxide dispersion strengthened (ODS) steel tubes by magnetic Barkhausen emission (MBE) technique. The high frequency MBE measurements (125 Hz sweep frequency and 70-200 kHz analyzing frequency) are found to be very sensitive for detection of presence of MS on the surface of the ODS steel tube. However, due to a shallow depth of information from the high frequency MBE measurements, it cannot be used for evaluation of the thickness of the embedded MS. The low frequency MBE measurements (0.5 Hz sweep frequency and 2-20 kHz analyzing frequency) indicate presence of two MBE RMS voltage peaks corresponding to the MS and the ODS steel. The ratio of the two peaks changes with the thickness of the MS and hence, can be used for measurement of the thickness of the MS layer.

The Structure of the Silumin Coat on Alloy Cast Steels

Directory of Open Access Journals (Sweden)

T. Szymczak

2012-04-01

Full Text Available The work presents the analysis results of the structure of the coat obtained by dipping in silumin AlSi5 of two grades of alloy cast steel: GX6CrNiTi18-10 (LH18N9T and GX39Cr13 (LH14. The temperature of the silumin bath was 750±5°C, and the hold-up time of the cast steel element τ = 180 s. The absolute thickness of the coat obtained in the given conditions was g = 104 μm on cast steel GX6CrNiTi18-10 and g = 132 μm on GX39Cr13. The obtained coat consisted of three layers of different phase structure. The first layer from the base “g1`” was constructed of the phase AlFe including Si and alloy additives of the tested cast steel grades: Cr and Ni (GX6CrNiTi18-10 and Cr (GX39Cr13. The second layer “g1``” of intermetallic phases AlFe which also contains Si and Cr crystallizes on it. The last, external layer “g2” of the coat consists of the silumin containing the intermetallic phases AlFeSi which additionally can contain alloy additives of the cast steel. It was shown that there were no carbides on the coat of the tested cast steels which are the component of their microstructure, as it took place in the case of the coat on the high speed steels.

[18S-25S rDNA variation in tissue culture of some Gentiana L. species].

Science.gov (United States)

Mel'nyk, V M; Andrieiev, I O; Spiridonova, K V; Strashniuk, N M; Kunakh, V A

2007-01-01

18S-25S rDNA of intact plants and tissue cultures of G. acaulis, G. punctata and G. lutea have been investigated by using blot-hybridization. The decrease of rDNA amount was found in the callus cultures as compared with the plants. In contrast to other species, G. lutea showed intragenome heterogeneity of rRNA genes as well as qualitative rDNA changes in tissue culture, in particular appearance of altered repeats. The relationship between the peculiarities of rRNA gene structure and their rearrangements in in vitro culture was suggested.

Topic 1. Steels for light water reactor pressure vessels

International Nuclear Information System (INIS)

Brumovsky, M.; Brynda, J.; Kepka, M.; Barackova, L.; Vacek, M.; Havel, S.; Cukr, B.; Protiva, K.; Petrman, I.; Tvrdy, M.; Hyspecka, L.; Mazanec, K.; Kupca, L.; Brezina, M.

1980-01-01

Part 1 of the Proceedings consists of papers on the criteria for the selection and comparison of the properties of steel for pressure vessels and on the metallurgy of the said steels, the selection of suitable material for internal tubing systems, the manufacture of high-alloy steels for WWER components, the mechanical and metallurgical properties of steel 22K for WWER 440 pressure components, and of steel 10MnNi2Mo for the WWER primary coolant circuit, and the metallographic assessment of steel 0Kh18N10T. (J.P.)

Spectroscopic characterisation of iodine deposits on 18%Cr/8%Ni and mild steel surfaces oxidised in CO2/CH3I gas mixtures

International Nuclear Information System (INIS)

Tyler, J.W.

1987-08-01

An understanding and quantification of iodine-131 attenuation within the gas circuit of a Commercial Advanced Gas-cooled Reactor is required for reactor safety assessments. To this end it is desirable to identify the chemical state of iodine in the gas phase or when deposited on reactor surfaces. Samples of 18%Cr/8%Ni and mild steel pipe, with iodine deposited on their surfaces following oxidation in CO 2 /CH 3 I gas mixtures, have been characterised in the present work using a variety of different spectroscopic techniques including X-ray photoelectron spectroscopy, scanning electron microscopy, energy dispersive X-ray analysis, scanning Auger microscopy and X-ray diffraction. The chemical nature of the deposited iodine has been determined by X-ray photoelectron spectroscopy to be a metal iodide by correlating I 3d binding energies with those obtained from well characterised standards; the binding energies of the ejected I 3d photoelectrons being sensitive to the chemical environment experienced by the iodine atoms. The distribution of iodine throughout the oxide layers formed on these steels was determined by repeated cycles of argon-ion bombardment and analysis to build up an elemental depth profile whilst at the same time determining the chemical state of the elements present. Differences in oxide composition and morphology are discussed in relation to the deposition behaviour observed on 18%Cr/8%Ni and mild steel and it is suggested that gradual incorporation of the iodine occurs throughout the oxidation/deposition period. (U.K.)

High Cr ODS steels R and D for high burnup fuel cladding

International Nuclear Information System (INIS)

Kimura, A.; Kasada, R.; Kishimoto, H.; Iwata, N.; Cho, H.-S.; Toda, N.; Yutani, K.; Ukai, S.; Fujiwara, M.

2007-01-01

High-performance cladding materials is essential to realize highly efficient and high-burnup operation over 150 GWd/t of so called Generation IV nuclear energy systems, such as supercritical-water-cooled reactor (SCWR) and lead-cooled fast reactor (LFR). Oxide dispersion strengthening (ODS) ferritic/ martensitic steels, which contain 9-12%Cr, show rather high resistance to neutron irradiation embrittlement and high strength at elevated temperatures. However, their corrosion resistance is not good enough in SCW and in lead at high temperatures. High-Cr ODS steels have been developed to improve corrosion resistance. An increase in Cr content an addition resulted in a drastic improvement of corrosion resistance in SCW and in lead. On the contrary, high-Cr steels often show an enhancement of aging embrittlement as well as irradiation embrittlement. Anisotropy in tensile properties is another issue. In order to overwhelm these issues, surveillance tests of the material performance have been performed for high Cr-ODS steels produced by new processing technologies. It is demonstrated that the dispersion of nono-sized oxide particles in high density is effective to attain high-performance and high-Cr ODS steels have a high potential as fuel cladding materials for SCWR and LFR with high efficiency and high burnup. (authors)

Aging Behaviour and Mechanical Performance of 18-Ni 300 Steel Processed by Selective Laser Melting

Directory of Open Access Journals (Sweden)

Riccardo Casati

2016-09-01

Full Text Available An 18-Ni 300 grade maraging steel was processed by selective laser melting and an investigation was carried out on microstructural and mechanical behaviour as a function of aging condition. Owing to the rapid cooling rate, the as-built alloy featured a full potential for precipitate strengthening, without the need of a solution treatment prior to aging. The amount of reversed austenite found in the microstructure increased after aging and revealed to depend on aging temperature and time. Similarly to the corresponding wrought counterpart, also in the selective laser-melted 18-Ni 300 alloy, aging promoted a dramatic increase in strength with respect to the as-built condition and a drop in tensile ductility. No systematic changes were found in tensile properties as a function of measured amount of austenite. It is proposed that the submicrometric structure and the phase distribution inherited by the rapid solidification condition brought by selective laser melting are such that changes in tensile strength and ductility are mainly governed by the effects brought by the strengthening precipitates, whereas the concurrent reversion of the γ-Fe phase in different amounts seems to play a minor role.

Hot Ductility Behaviors in the Weld Heat-Affected Zone of Nitrogen-Alloyed Fe-18Cr-10Mn Austenitic Stainless Steels

Science.gov (United States)

Moon, Joonoh; Lee, Tae-Ho; Hong, Hyun-Uk

2015-04-01

Hot ductility behaviors in the weld heat-affected zone (HAZ) of nitrogen-alloyed Fe-18Cr-10Mn austenitic stainless steels with different nitrogen contents were evaluated through hot tension tests using Gleeble simulator. The results of Gleeble simulations indicated that hot ductility in the HAZs deteriorated due to the formation of δ-ferrite and intergranular Cr2N particles. In addition, the amount of hot ductility degradation was strongly affected by the fraction of δ-ferrite.

Fatigue Strength of Weathering Steel

Czech Academy of Sciences Publication Activity Database

Kunz, Ludvík; Lukáš, Petr; Klusák, Jan

2012-01-01

Roč. 18, č. 1 (2012), s. 18-22 ISSN 1392-1320 Grant - others:GA MPO(CZ) FT/TA5/076 Institutional support: RVO:68081723 Keywords : fatigue of weathering steel * corrosion pits * fatigue notch factor Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 0.522, year: 2012

Research of Technological Properties of Steel X6CRNITI18-10 Welded Joints Exploited in Nitric Acid Medium

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Gediminas Mikalauskas

2016-04-01

Full Text Available The repair of chemical industry equipments often requires to replace long time operated pipes or welded inserts with the simi-lar chemical composition. During the study the joints from corro-sion resistant steel X6CrNiTi18-10 were welded by manual metal arc welding with covered electrodes (MMA process 111 and tungsten inert gas welding (TIG process 141 at different welding parameters. The visual, radiographic, penetrant control and ferrite content analysis were carried out. The transverse tensile and bending samples were produced from welded samples; also the macroscopic and microscopic analyse were carried out.

Omvårdnadsåtgärder för att minska rädsla, oro och ångest hos barn 0-18 år i samband med en röntgenundersökning : En litteraturstudie

OpenAIRE

Mohsen, Nadja; Imsirovic, Amela

2016-01-01

Bakgrund: Att besöka en röntgenavdelning kan vara något nytt och skrämmande för många barn. Den nya miljön kan orsaka rädsla, oro och ångest hos barn. Därför är det viktigt att röntgensjuksköterskan har kunskap om barnets behov för att upplevelsen på röntgenavdelningen ska vara så bra som möjligt. Syfte: Syftet med den här studien är att beskriva omvårdnadsåtgärder för att minska rädsla, oro och ångest hos barn 0-18 år i samband med röntgenundersökning. Metod: Detta arbete är en litteraturstu...

Feasibility study on decontamination of the contaminated stainless steel with HBF4 solution

International Nuclear Information System (INIS)

Dong Ruilin; Zhang Yuan; Qiu Dangui; Huang Yuying; Ren Xianwen

2002-01-01

Decontamination experiments were carried out with HBF 4 solution on the following four kinds of sample: 1Cr18Ni9Ti stainless steel with and without welding line, 1Cr18Ni9Ti stainless steel with oxide layer formed in boiling concentrated nitric acid solution, natural uranium and 230 Th contaminated stainless steel pipe sample from one decommissioning nuclear facility. The results indicated that the oxide layer, the welding line of the 1Cr18Ni9Ti stainless steel and itself can be dissolved in the HBF 4 decontamination solution. The solubility of the 1Cr18Ni9Ti stainless steel in the HBF 4 solution used in the test is more than 5 g/L, which means that the 0.13 m 2 stainless steel could be dissolved up to a thickness of 5 μm in one liter of decontamination solution. The decontamination efficiency is more than 85% in 30 minutes for the 230 Th contaminated sample, and 87% in 2 hours for the natural uranium contaminated sample. Both samples could be decontaminated to the background level after several runs of the decontamination

Notch aspects of RSP steel microstructure

Directory of Open Access Journals (Sweden)

Michal Černý

2012-01-01

Full Text Available For a rather long time, basic research projects have been focused on examinations of mechanical properties for Rapid Solidification Powder (RSP steels. These state-of-art steels are commonly known as “powdered steels“. In fact, they combine distinctive attributes of conventional steel alloys with unusual resistance of construction material manufactured by so called “pseudo-powdered” metallurgy.Choice of suitable materials for experimental verification was carried out based on characteristic application of so called “modern steel”. First, groups of stainless and tool steel types (steel grades ČSN 17 and 19 were selected. These provided representative specimens for the actual comparison experiment. For stainless steel type, two steel types were chosen: hardenable X47Cr14 (ČSN 17 029 stainless steel and non-hardenable X2CrNiMo18-14-3 (ČSN 17 350 steel. They are suitable e.g. for surgical tools and replacements (respectively. For tooling materials, C80U (ČSN 19 152 carbon steel and American D2 highly-alloyed steel (ČSN “equivalent” being 19 572 steel were chosen for the project. Finally, the M390 Böhler steel was chosen as representative of powdered (atomized steels. The goal of this paper is to discuss structural aspects of modern stainless and tool steel types and to compare them against the steel made by the RSP method. Based on the paper's results, impact of powdered steel structural characteristics on the resistance to crack initiation shall be evaluated.

Precipitation and impact toughness of Nb–V stabilised 18Cr–2Mo ferritic stainless steel during isothermal aging

International Nuclear Information System (INIS)

Han, Jian; Li, Huijun; Barbaro, Frank; Jiang, Laizhu; Zhu, Zhixiong; Xu, Haigang; Ma, Li

2014-01-01

The effect of isothermal aging on precipitation behaviour and Charpy impact toughness of Nb–V stabilised 18Cr–2Mo ferritic stainless steel was investigated by means of Thermo-Calc prediction, scanning electron microscopy, transmission electron microscopy, X-ray diffraction and Charpy impact toughness testing. The results show that, niobium, vanadium carbides and nitrides, Fe 2 Nb (Laves phase) and Cr 23 C 6 formed after 2 h aging at 800 °C, and the equilibrium solvus temperature of Fe 2 Nb phase increases to above 750 °C, higher than the calculated temperature (730 °C) using Thermo-Calc. After isothermal aging at 750–950 °C, 2 h aging resulted in a decrease in toughness due to the formation of precipitation, especially (Nb,V)(C,N) and Fe 2 Nb. When isothermally aged at 800 °C for up to 24 h, the coarsening rate of Fe 2 Nb particle is much higher than that of (Nb,V)(C,N), and the impact toughness of the steel is dependent on quantity and sizes of (Nb,V)(C,N) and Fe 2 Nb particles

Precipitation and impact toughness of Nb–V stabilised 18Cr–2Mo ferritic stainless steel during isothermal aging

Energy Technology Data Exchange (ETDEWEB)

Han, Jian, E-mail: jh595@uowmail.edu.au [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522 (Australia); Li, Huijun [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522 (Australia); Barbaro, Frank [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522 (Australia); CBMM Technology Suisse, 14, Rue du Rhone, Geneve 1204 (Switzerland); Jiang, Laizhu [Baoshan Iron and Steel Co., Ltd., Shanghai 200431 (China); Zhu, Zhixiong [School of Mechanical, Materials and Mechatronic Engineering, University of Wollongong, Wollongong, NSW 2522 (Australia); Xu, Haigang; Ma, Li [Baoshan Iron and Steel Co., Ltd., Shanghai 200431 (China)

2014-08-26

The effect of isothermal aging on precipitation behaviour and Charpy impact toughness of Nb–V stabilised 18Cr–2Mo ferritic stainless steel was investigated by means of Thermo-Calc prediction, scanning electron microscopy, transmission electron microscopy, X-ray diffraction and Charpy impact toughness testing. The results show that, niobium, vanadium carbides and nitrides, Fe{sub 2}Nb (Laves phase) and Cr{sub 23}C{sub 6} formed after 2 h aging at 800 °C, and the equilibrium solvus temperature of Fe{sub 2}Nb phase increases to above 750 °C, higher than the calculated temperature (730 °C) using Thermo-Calc. After isothermal aging at 750–950 °C, 2 h aging resulted in a decrease in toughness due to the formation of precipitation, especially (Nb,V)(C,N) and Fe{sub 2}Nb. When isothermally aged at 800 °C for up to 24 h, the coarsening rate of Fe{sub 2}Nb particle is much higher than that of (Nb,V)(C,N), and the impact toughness of the steel is dependent on quantity and sizes of (Nb,V)(C,N) and Fe{sub 2}Nb particles.

Recent progress of R and D activities on reduced activation ferritic/martensitic steels

Energy Technology Data Exchange (ETDEWEB)

Huang, Q., E-mail: qunying.huang@fds.org.cn [Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, P.O. Box 1135, Hefei, Anhui 230031 (China); Baluc, N. [CRPP-EPFL, ODGA C110 5232 Villigen PSI (Switzerland); Dai, Y. [LNM, PSI, 5232 Villigen PSI (Switzerland); Jitsukawa, S. [JAEA, 2-4 Shirakata, Tokai-Mura, Ibaraki-Ken 319-1195 (Japan); Kimura, A. [IAE, Kyoto University, Gokasho, Uji, Kyoto 611-0011 (Japan); Konys, J. [KIT, P.O. Box 3640, 76021 Karlsruhe (Germany); Kurtz, R.J. [PNNL, Richland, WA 99352 (United States); Lindau, R. [KIT, P.O. Box 3640, 76021 Karlsruhe (Germany); Muroga, T. [NIFS, Oroshi, Toki, Gifu 509-5292 (Japan); Odette, G.R. [UCSB, Santa Barbara, CA (United States); Raj, B. [IGCAR, Kalpakkam 603 102 (India); Stoller, R.E.; Tan, L. [ORNL, P.O. Box 2008, Oak Ridge, TN 37831 (United States); Tanigawa, H. [JAEA, Naka, Ibaraki 311-0193 (Japan); Tavassoli, A.-A.F. [DMN/Dir, DEN, CEA Saclay, 91191 Gif-sur-Yvette cedex (France); Yamamoto, T. [UCSB, Santa Barbara, CA (United States); Wan, F. [DMPC, USTB, Beijing 100083 (China); Wu, Y. [Institute of Nuclear Energy Safety Technology, Chinese Academy of Sciences, P.O. Box 1135, Hefei, Anhui 230031 (China)

2013-11-15

Several types of reduced activation ferritic/martensitic (RAFM) steel have been developed over the past 30 years in China, Europe, India, Japan, Russia and the USA for application in ITER test blanket modules (TBMs) and future fusion DEMO and power reactors. The progress has been particularly important during the past few years with evaluation of mechanical properties of these steels before and after irradiation and in contact with different cooling media. This paper presents recent RAFM steel results obtained in ITER partner countries in relation to different TBM and DEMO options.

[Phylogeny of protostome moulting animals (Ecdysozoa) inferred from 18 and 28S rRNA gene sequences].

Science.gov (United States)

Petrov, N B; Vladychenskaia, N S

2005-01-01

Reliability of reconstruction of phylogenetic relationships within a group of protostome moulting animals was evaluated by means of comparison of 18 and 28S rRNA gene sequences sets both taken separately and combined. Reliability of reconstructions was evaluated by values of the bootstrap support of major phylogenetic tree nodes and by degree of congruence of phylogenetic trees inferred by various methods. By both criteria, phylogenetic trees reconstructed from the combined 18 and 28S rRNA gene sequences were better than those inferred from 18 and 28S sequences taken separately. Results obtained are consistent with phylogenetic hypothesis separating protostome animals into two major clades, moulting Ecdysozoa (Priapulida + Kinorhyncha, Nematoda + Nematomorpha, Onychophora + Tardigrada, Myriapoda + Chelicerata, Crustacea + Hexapoda) and unmoulting Lophotrochozoa (Plathelminthes, Nemertini, Annelida, Mollusca, Echiura, Sipuncula). Clade Cephalorhyncha does not include nematomorphs (Nematomorpha). Conclusion was taken that it is necessary to use combined 18 and 28S data in phylogenetic studies.

Overview of Materials R&D at Oak Ridge National Laboratory

Science.gov (United States)

2010-08-23

Commercial Bainitic Steel ORNL “Super” Bainitic Steel 500 400 300 200 100 0 0 2 4 6 8 10 12 TIME (h) C R E E P S T R A IN (% ) 347HFG SS...14 trillion BTU/yr Laser-Assisted Friction Stir Welding  Enable Solid-State Joining of High Temperature Materials, Steel and... Steel structures – Complex and thick sectioned structures – On-site construction capability 12 Field Deployable FSW • Capability for joining of

Structure and properties of joints of two-ply steel using ''elastic'' explosives

International Nuclear Information System (INIS)

Gel'man, A.S.; Savel'ev, S.A.; Kulakevich, Ya.S.; Sharypov, N.A.; Drogovejko, I.Z.; Domolego, I.E.

1980-01-01

Some experimental data on structure and properties of compounds during cladding of sheets made of St3 with sheets of nichrome and steel 12Kh18N10T with the use of ''elastic'' explosives are presented. It is shown that the use of ''elastic'' explosives permits to decrease r parameter sufficiently, (where r - is the ratio of explosive mass to the mass of throwen phate) that reduces considerably the specific consumption explosives in comparison with the consumption conventional mixture explosives. Peculiarities of tested ''elastic'' explosives make their application perspective in two cases - at cladding of complex curved surfaces (drums, tube blanks etc.), as sell as at applications of burst chambers, where explosive mass limits dimensions of cladding blanks and details [ru

Stainless steels in boiling water reactors. Corrosion problems and possible solutions

International Nuclear Information System (INIS)

Combrade, P.; Desestret, A.; Leroy, F.; Coriou, H.

1977-01-01

In boiling water reactors, the heat-carrying water may have an up to 0.1 or even 0.2 ppm oxygen content, which can make it highly agressive at operating temperature for stainless steels subject to high physical stresses. Several metallurgical solutions can be considered, and in particular the use of stainless steels having a mixed austenitic-ferritic structure or of standard austenitic steels (18.10 or 18.10 Mo, such as AISI 304 and 316) with carefully controlled carbon and alloy element contents. The behavior of these steels during prolonged tests in water at 288 0 C with a 30 and even 100 ppm oxygen content turned out to be quite satisfactory [fr

Effect of nitrogen alloying of stainless steels on their corrosion stability

International Nuclear Information System (INIS)

Chigal, V.; Knyazheva, V.M.; Pitter, Ya.; Babich, S.G.; Bogolyubskij, S.D.

1986-01-01

Results of corrosion tests and structural investigations of 03Cr18Ni10 and 03Cr18Ni10Mo3 steels without nitrogen and with nitrogen content of 0.15-0.3% are presented. Corrosion-electrochemical behaviour of Cr20Ni20 steel with ultralow carbon content (0.004-0.006%) and nitrogen content with 0-0.5% as well as Cr 2 N nitride behaviour are investigated. A conclusion is made on nitrogen and excessive nitride phase effect on corrosion stability of steel in corrosive media with different reduction-oxidation properties

Characterization of Hydrocortisone Biometabolites and 18S rRNA Gene in Chlamydomonas reinhardtii Cultures

Directory of Open Access Journals (Sweden)

Seyed Bagher Mosavi-Azam

2008-10-01

Full Text Available A unicellular microalga, Chlamydomonas reinhardtii, was isolated from rice paddy-field soil and water samples and used in the biotransformation of hydrocortisone (1. This strain has not been previously tested for steroid bioconversion. Fermentation was carried out in BG-11 medium supplemented with 0.05% substrate at 25ºC for 14 days of incubation. The products obtained were chromatographically purified and characterized using spectroscopic methods. 11b,17b-Dihydroxyandrost-4-en-3-one (2, 11b-hydroxyandrost-4-en-3,17-dione (3, 11b,17a,20b,21-tetrahydroxypregn-4-en-3-one (4 and prednisolone (5 were the main products of the bioconversion. The observed bioreaction features were the side chain degradation of the substrate to give compounds 2 and 3 and the 20-ketone reduction and 1,2-dehydrogenation affording compounds 4 and 5, respectively. A time course study showed the accumulation of product 2 from the second day of the fermentation and of compounds 3, 4 and 5 from the third day. All the metabolites reached their maximum concentration in seven days. Microalgal 18S rRNA gene was also amplified by PCR. PCR products were sequenced to confirm their authenticity as 18S rRNA gene of microalgae. The result of PCR blasted with other sequenced microalgae in NCBI showed 100% homology to the 18S small subunit rRNA of two Chlamydomonas reinhardtii spp.

Characterization of hydrocortisone biometabolites and 18S rRNA gene in Chlamydomonas reinhardtii cultures.

Science.gov (United States)

Ghasemi, Younes; Rasoul-Amini, Sara; Morowvat, Mohammad Hossein; Raee, Mohammad Javad; Ghoshoon, Mohammad Bagher; Nouri, Fatemeh; Negintaji, Narges; Parvizi, Rezvan; Mosavi-Azam, Seyed Bagher

2008-10-31

A unicellular microalga, Chlamydomonas reinhardtii, was isolated from rice paddy-field soil and water samples and used in the biotransformation of hydrocortisone (1). This strain has not been previously tested for steroid bioconversion. Fermentation was carried out in BG-11 medium supplemented with 0.05% substrate at 25 degrees C for 14 days of incubation. The products obtained were chromatographically purified and characterized using spectroscopic methods. 11b,17 beta-Dihydroxyandrost-4-en-3-one (2), 11 beta-hydroxyandrost-4-en-3,17-dione (3), 11 beta,17 alpha,20 beta,21-tetrahydroxypregn-4-en-3-one (4) and prednisolone (5) were the main products of the bioconversion. The observed bioreaction features were the side chain degradation of the substrate to give compounds 2 and 3 and the 20-ketone reduction and 1,2-dehydrogenation affording compounds 4 and 5, respectively. A time course study showed the accumulation of product 2 from the second day of the fermentation and of compounds 3, 4 and 5 from the third day. All the metabolites reached their maximum concentration in seven days. Microalgal 18S rRNA gene was also amplified by PCR. PCR products were sequenced to confirm their authenticity as 18S rRNA gene of microalgae. The result of PCR blasted with other sequenced microalgae in NCBI showed 100% homology to the 18S small subunit rRNA of two Chlamydomonas reinhardtii spp.

Simple Heat Treatment for Production of Hot-Dip Galvanized Dual Phase Steel Using Si-Al Steels

Science.gov (United States)

Equihua-Guillén, F.; García-Lara, A. M.; Muñíz-Valdes, C. R.; Ortíz-Cuellar, J. C.; Camporredondo-Saucedo, J. E.

2014-01-01

This work presents relevant metallurgical considerations to produce galvanized dual phase steels from low cost aluminum-silicon steels which are produced by continuous strip processing. Two steels with different contents of Si and Al were austenized in the two-phase field ferrite + austenite (α + γ) in a fast manner to obtain dual phase steels, suitable for hot-dip galvanizing process, under typical parameters of continuous annealing processing line. Tensile dual phase properties were obtained from specimens cooled from temperature below Ar3, held during 3 min, intermediate cooling at temperature above Ar1 and quenching in Zn bath at 465 °C. The results have shown typical microstructure and tensile properties of galvanized dual phase steels. Finally, the synergistic effect of aluminum, silicon, and residual chromium on martensite start temperature ( M s), critical cooling rate ( C R), volume fraction of martensite, and tensile properties has been studied.

Engineering of rolled constructional microalloyed steel products

International Nuclear Information System (INIS)

Adamczyk, J.

2003-01-01

Flexibility of the microalloyed steels on manufacturing of products with high mechanical and technological properties at not exaggerated production costs, it caused of their application for different constructions and machines in many branches of economy. It is a reason of the big interest of this steel group and the improvement of metallurgical and technological processing. In the work the examples of applications of C-Mn microalloyed steels with V and N microadditions for production of long shape products of R p0.2 > 650 MPa and KCU2 > 57 Jcm -2 are presented. They are manufactured in the controlled rolling process. Moreover this work presents liquid metal treatment in ladlemann process and influence of ingots solidification conditions, controlled rolling of weldable plates with Nb, Ti, V and B microadditions which after quenching and tempering have R p0.2 > 870 MPa, KV -50 o C > 27 J and plastic strain ratio equals 1.2. This work also presents the energy saving rolling technology with controlled recrystallization (method of thermomechanical treatment) of improved Weldox 960 steel plates with Mb, Ti, V and B microadditions which have after high-temperature tempering R p0.2 > 100 MPa, KV -50 o C >90 J and plastic strain ratio is less than 1.2. The introduction of microalloyed constructional steels and the appropriate technology in the domestic industry will contribute to high-processed products with properties competitive to products manufactured in high-industrialized countries. Thanks to that it will be possible to increase the technical level as well as to reduce production costs and import. (author)

Technology Roadmap Research Program for the Steel Industry

Energy Technology Data Exchange (ETDEWEB)

Joseph R. Vehec

2010-12-30

The steel industry's Technology Roadmap Program (TRP) is a collaborative R&D effort jointly sponsored by the steel industry and the United States Department of Energy. The TRP program was designed to develop new technologies to save energy , increase competitiveness, and improve the environment. TRP ran from July, 1997 to December, 2008, with a total program budget of $38 million dollars. During that period 47 R&D projects were performed by 28 unique research organizations; co-funding was provided by DOE and 60 industry partners. The projects benefited all areas of steelmaking and much know-how was developed and transferred to industry. The American Iron and Steel Institute is the owner of all intellectual property developed under TRP and licenses it at commercial rates to all steelmakers. TRP technologies are in widespread use in the steel industry as participants received royalty-free use of intellectual property in return for taking the risk of funding this research.

An updated 18S rRNA phylogeny of tunicates based on mixture and secondary structure models

Directory of Open Access Journals (Sweden)

Shenkar Noa

2009-08-01

Full Text Available Abstract Background Tunicates have been recently revealed to be the closest living relatives of vertebrates. Yet, with more than 2500 described species, details of their evolutionary history are still obscure. From a molecular point of view, tunicate phylogenetic relationships have been mostly studied based on analyses of 18S rRNA sequences, which indicate several major clades at odds with the traditional class-level arrangements. Nonetheless, substantial uncertainty remains about the phylogenetic relationships and taxonomic status of key groups such as the Aplousobranchia, Appendicularia, and Thaliacea. Results Thirty new complete 18S rRNA sequences were acquired from previously unsampled tunicate species, with special focus on groups presenting high evolutionary rate. The updated 18S rRNA dataset has been aligned with respect to the constraint on homology imposed by the rRNA secondary structure. A probabilistic framework of phylogenetic reconstruction was adopted to accommodate the particular evolutionary dynamics of this ribosomal marker. Detailed Bayesian analyses were conducted under the non-parametric CAT mixture model accounting for site-specific heterogeneity of the evolutionary process, and under RNA-specific doublet models accommodating the occurrence of compensatory substitutions in stem regions. Our results support the division of tunicates into three major clades: 1 Phlebobranchia + Thaliacea + Aplousobranchia, 2 Appendicularia, and 3 Stolidobranchia, but the position of Appendicularia could not be firmly resolved. Our study additionally reveals that most Aplousobranchia evolve at extremely high rates involving changes in secondary structure of their 18S rRNA, with the exception of the family Clavelinidae, which appears to be slowly evolving. This extreme rate heterogeneity precluded resolving with certainty the exact phylogenetic placement of Aplousobranchia. Finally, the best fitting secondary-structure and CAT-mixture models

Gradient microstructure and microhardness in a nitrided 18CrNiMo7-6 gear steel

Science.gov (United States)

Yang, R.; Wu, G. L.; Zhang, X.; Fu, W. T.; Huang, X.

2017-07-01

A commercial gear steel (18CrNiMo7-6) containing a tempered martensite structure was nitrided using a pressurized gas nitriding process under a pressure of 5 atm at 530 °C for 5 hours. The mechanical properties and microstructure of the nitrided sample were characterized by Vickers hardness measurements, X-ray diffraction, and backscatter electron imaging in a scanning electron microscope. A micro-hardness gradient was identified over a distance of 500 μm with hardness values of 900 HV at the top surface and 300 HV in the core. This micro-hardness gradient corresponds to a gradient in the microstructure that changes from a nitride compound layer at the top surface (∼ 20 μm thick) to a diffusion zone with a decreasing nitrogen concentration and precipitate density with distance from the surface, finally reaching the core matrix layer with a recovered martensite structure.

Fatigue and fracture behavior of low alloy ferritic forged steels

International Nuclear Information System (INIS)

Chaudhry, V.; Sharma, A.K.; Muktibodh, U.C.; Borwankar, Neeraj; Singh, D.K.; Srinivasan, K.N.; Kulkarni, R.G.

2016-01-01

Low alloy ferritic steels are widely used in nuclear industry for the construction of pressure vessels. Pressure vessel forged low alloy steels 20MnMoNi55 (modified) have been developed indigenously. Experiments have been carried out to study the Low Cycle Fatigue (LCF) and fracture behavior of these forged steels. Fully reversed strain controlled LCF testing at room temperature and at 350 °C has been carried out at a constant strain rate, and for different axial strain amplitude levels. LCF material behavior has been studied from cyclic stress-strain responses and the strain-life relationships. Fracture behavior of the steel has been studied based on tests carried out for crack growth rate and fracture toughness (J-R curve). Further, responses of fatigue crack growth rate tests have been compared with the rate evaluated from fatigue precracking carried out for fracture toughness (J-R) tests. Fractography of the samples have been carried out to reveal dominant damage mechanisms in crack propagation and fracture. The fatigue and fracture properties of indigenously developed low alloy steel 20MnMoNi55 (modified) steels are comparable with similar class of steels. (author)

Corrosion fatigue crack growth in clad low-alloy steels: Part 1, medium-sulfur forging steel

International Nuclear Information System (INIS)

James, L.A.; Poskie, T.J.; Auten, T.A.; Cullen, W.H.

1996-01-01

Corrosion fatigue crack propagation tests were conducted on a medium- sulfur ASTM A508-2 forging steel overlaid with weld-deposited Alloy EN82H cladding. The specimens featured semi-elliptical surface cracks penetrating approximately 6.3 mm of cladding into the underlying steel. The initial crack sizes were relatively large with surface lengths of 30.3--38.3 mm, and depths of 13.1--16.8 mm. The experiments were conducted in a quasi-stagnant low-oxygen (O 2 < 10 ppb) aqueous environment at 243 degrees C, under loading conditions (ΔK, R, and cyclic frequency) conductive to environmentally-assisted cracking (EAC) in higher-sulfur steels under quasi-stagnant conditions. Earlier experiments on unclad compact tension specimens of this heat of steel did not exhibit EAC, and the present experiments on semi-elliptical surface cracks penetrating cladding also did not exhibit EAC

High yttria ferritic ODS steels through powder forging

Science.gov (United States)

Kumar, Deepak; Prakash, Ujjwal; Dabhade, Vikram V.; Laha, K.; Sakthivel, T.

2017-05-01

Oxide dispersion strengthened (ODS) steels are being developed for future nuclear reactors. ODS Fe-18%Cr-2%W-0.2%Ti steels with 0, 0.35, 0.5, 1 and 1.5% Y2O3 (all compositions in weight%) dispersion were fabricated by mechanical alloying of elemental powders. The powders were placed in a mild steel can and forged in a stream of hydrogen gas at 1473 K. The steels were forged again to final density. The strength of ODS steel increased with yttria content. Though this was accompanied by a decrease in tensile elongation, all the steels showed significant ductility. The ductility in high yttria alloys may be attributed to improved inter-particle bonding between milled powders due to reduction of surface oxides by hydrogen. This may permit development of ODS steels with yttria contents higher than the conventional limit of 0.5%. It is suggested that powder forging is a promising route to fabricate ODS steels with high yttria contents and improved ductility.

Microstructural Characterization of Friction Stir Welded Aluminum-Steel Joints

Science.gov (United States)

2013-08-01

Sterling, R.J. Steel, C.-O. Pettersson. “Microstructure and mechanical properties of friction stir welded SAF 2507 super duplex stainless steel.” Mater...MICROSTRUCTURAL CHARACTERIZATION OF FRICTION STIR WELDED ALUMINUM-STEEL JOINTS By ERIN ELIZABETH PATTERSON A thesis submitted in...for his work producing the dissimilar weld samples used in this study. Without his work, this project would not have been possible. I would also

Microstructural investigations of fatigued 12% Cr-steel 1.4914 (X 18 Cr Mo V Nb 12 1)

International Nuclear Information System (INIS)

Gersinska, R.

1992-10-01

The low cycle fatigue properties of a tempered steel X18 Cr Mo V Nb 12 1 (DIN 1.4914) have been investigated at different temperatures, strain amplitudes, mean strains and strain rates. The role of martensite lath structure and of precipitates and dislocations on the strengthening mechanisms and fatigue damage have been analysed. Plastic deformation results in a slip band formation on the surface and in a cellular dislocation structure in the interior of the specimens. A reduced strain rate is causing lower stress amplitudes and greater cells at higher temperatures. At lower temperatures the influence of strain rate is small. Fatigue mechanisms are soon dominant at lower strain rates. REM-investigations of the specimen surfaces are revealing the development of cracks at slip bands. The cracks start always at the surfaces of the specimen, and they are transcristalline in nature. The influence of the ageing temperature has been investigated. A reduced ageing temperature of 600degC results in a higher dislocation density and a lower martensite lath distance in the undeformed material. Strain ageing was initially observed in tensile experiments. The influence of dynamic strain ageing on the mechanical properties and the microstructure of tempered steel 1.4914 is investigated. A correlation of mechanical and microstructural data has been performed. (orig./MM) [de

Microstructural defect evolution in neutron – Irradiated 12Cr18Ni9Ti stainless steel during subsequent isochronous annealing

Energy Technology Data Exchange (ETDEWEB)

Tsay, K.V.; Maksimkin, O.P.; Turubarova, L.G.; Rofman, O.V. [Institute of Nuclear Physics NNC RK, Almaty (Kazakhstan); Garner, F.A., E-mail: frank.garner@dslextreme.com [Radiation Effects Consulting, Richland, WA (United States)

2013-08-15

Transmission electron microscopy and microhardness measurements were used to examine changes in microstructure and associated strengthening induced in austenitic stainless steel 12Cr18Ni9Ti irradiated to ∼0.001 and ∼5 dpa in the WWR-K reactor before and after being subjected to post-irradiation isochronal annealing. The relatively low values of irradiation temperature and dpa rate (∼80 °C and ∼1.2 × 10{sup −8} dpa/s) experienced by this steel allowed characterization of defect microstructures over a wide range of defect ensembles, all at constant composition, produced first by irradiation and then by annealing at temperatures between 450 and 1050 °C. It was shown that the dispersed barrier hardening model with commonly accepted physical properties successfully predicted the observed hardening. It was also observed that when TiC precipitates form at higher annealing temperatures, the alloy does not change in hardness, reflecting a balance between precipitate-hardening and matrix-softening due to removal of solute-strengthening elements titanium and carbon. Such matrix-softening is not often considered in other studies, especially where the contribution of precipitates to hardening is a second-order effect.

Microstructural defect evolution in neutron – Irradiated 12Cr18Ni9Ti stainless steel during subsequent isochronous annealing

International Nuclear Information System (INIS)

Tsay, K.V.; Maksimkin, O.P.; Turubarova, L.G.; Rofman, O.V.; Garner, F.A.

2013-01-01

Transmission electron microscopy and microhardness measurements were used to examine changes in microstructure and associated strengthening induced in austenitic stainless steel 12Cr18Ni9Ti irradiated to ∼0.001 and ∼5 dpa in the WWR-K reactor before and after being subjected to post-irradiation isochronal annealing. The relatively low values of irradiation temperature and dpa rate (∼80 °C and ∼1.2 × 10 −8 dpa/s) experienced by this steel allowed characterization of defect microstructures over a wide range of defect ensembles, all at constant composition, produced first by irradiation and then by annealing at temperatures between 450 and 1050 °C. It was shown that the dispersed barrier hardening model with commonly accepted physical properties successfully predicted the observed hardening. It was also observed that when TiC precipitates form at higher annealing temperatures, the alloy does not change in hardness, reflecting a balance between precipitate-hardening and matrix-softening due to removal of solute-strengthening elements titanium and carbon. Such matrix-softening is not often considered in other studies, especially where the contribution of precipitates to hardening is a second-order effect

Influence of aging condition and reversion austenite on fatigue property of the 300 grade 18Ni maraging steel

International Nuclear Information System (INIS)

Moriyama, Michihiko; Takaki, Setsuo; Kawagoishi, Norio

2000-01-01

The influence of aging condition on fatigue strength of the 300 grade 18Ni maraging steel has been investigated in relation to the behavior of age hardening and the formation of reversion austenite. In this study, rotating bending fatigue tests were performed for three series of specimens with different aging condition; as solution-treated without aging, aged for various time at 753 K which is the temperature applied for the industrial aging treatment, and over-aged to form a small amount of reversion austenite. Effect of reversion austenite on fatigue strength was examined using specimens with the same static strength which had been controlled by varying aging temperature and time, namely under-aging or over-aging. The main results obtained are as follows. (1) In the case of 753 K aging, the fatigue limits of specimens aged for 11 ks to 48 ks were nearly the same value, although an under-aged (2.8 ks) specimen has as much lower value as a solution-treated specimen without aging treatment. (2) A small amount of reversion austenite is effective for increasing fatigue resistance. For instance, 2 vol% of austenite was enough for improving fatigue limit of the maraging steel used, from 580 MPa to 640 MPa at the same hardness level of Hv 610. (author)

Creep modelling of type 316LN stainless steel

International Nuclear Information System (INIS)

Kim, W. G.; Kim, D. H.; Ryu, W. S.

2000-01-01

Creep curve for type 316LN stainless steel was modelled by using the K-R damage equations. Seven coefficients used in the model, i. e., A, B, κ, m, λ, r, and q were determined from theoretical and calculated data, and their meanings were also analyzed. To quantify damage formation parameter(ω), cavity amount was measured on the crept specimen taken from an interrupted creep test with time variation, and then the amount was reflected into K-R damage equations. Coefficient λ which is regarded as a creep tolerance feature of a material increased with increase of creep strain. Theoretical curve in λ= 3.0 well coincided with an experimental one to the full level of lifetime. Master curve between damage parameter and life fraction matched with the theoretical one in exponent γ= 24 value, which decreased with increase of parameter ω which increased rapidly after 80% life fraction. It is concluded that K-R equation was reliable as the modelling equation for 316LN stainless steel. Coefficient data obtained from 316LN stainless steel can be utilized for remaining life prediction of operating material

W–steel and W–WC–steel composites and FGMs produced by hot pressing

Czech Academy of Sciences Publication Activity Database

Matějíček, Jiří; Boldyryeva, Hanna; Brožek, Vlastimil; Sachr, P.; Chráska, Tomáš; Pala, Zdeněk

2015-01-01

Roč. 100, November (2015), s. 364-370 ISSN 0920-3796 R&D Projects: GA ČR(CZ) GAP108/12/1872 EU Projects: European Commission(DE) WP11-MAT-WWALLOY Institutional support: RVO:61389021 Keywords : FGM * Composite * Tungsten * Steel * Fusion reactor material Subject RIV: JF - Nuclear Energetics OBOR OECD: Nuclear related engineering Impact factor: 1.301, year: 2015 http://www.sciencedirect.com/science/article/pii/S0920379615302106

Plasticity of low carbon stainless steels

International Nuclear Information System (INIS)

Bulat, S.I.; Fel'dgandler, Eh.G.; Kareva, E.N.

1975-01-01

In the temperature range 800-1200 0 C and with strain rates of from 10 -3 to 3 s -1 , austenitic (000Kh18N12) and austenitic-ferrite (000Kh26N6) very low carbon stainless steels containing 0.02-0.03% C exhibit no higher resilience than corresponding ordinary steels containing 0.10-0.12% C. However, the plasticity of such steels (particularly two-phase steels) at 900-1100 0 C is appreciably inferior owing to the development of intergranular brittle fracture. Pressure treatment preceded by partial cooling of the surface to 850 0 C yields rolled and forged products with acceptable indices but is inconvenient technically. At the Zlatoustovsk and Ashin metallurgical plants successful tests have been performed involving the forging and rolling of such steels heated to 1280-1300 0 C without partial cooling; it was necessary to improve the killing conditions, correct the chemical composition (increasing the proportion of ferrite) and take measures against heat loss. (author)

Influence of cerium, zirconium and boron on the oxidation resistance of heat-resistant steels in air

International Nuclear Information System (INIS)

Gala, A.; Schendler, W.

1981-01-01

Isothermal and cyclic oxidation experiments were carried out in air to investigate the influence of the minor elements such as Cerium, Zirkonium and Boron on the oxidation resistance of heat resistant ferritic and austenitic steels like X10Cr18, X10CrAl18 and X15CrNiSi2012. In the case of cyclicexperiments samples were exposed at constant temperatures for 100 h and then cooled to R.T. This cycle was repeated 10 times. The corrosion was determined as weight change and was continuously measured by a thermo-balance. The distribution of the alloying elements on the phase boundary scale/steel was examined by Scanning-Electron-Microscope. Addition of small amounts of Ce (0.3 wt-% max.) could reduce the oxidation rate in the case of isothermal and cyclic conditions. Zirkonium concentrations below 0.1 wt-% could have a beneficial effect, but at higher concentrations the oxidation rate increases with increasing amounts of Zr. Small Boron concentrations of 0.02 wt-% lead to catastrophic oxidation at temperatures above 1000 0 C. (orig.) [de

Non-destructive automated express method for determining the inclination of chromium-nickel steels IGC

International Nuclear Information System (INIS)

Nazarov, A.A.; Kamenev, Yu.B.; Kuusk, L.V.; Kormin, E.G.; Vasil'ev, A.N.; Sumbaeva, T.E.

1986-01-01

Methods of automated control of 18-10-type steel inclination to IGC are developed and a corresponding automated testing complex (ATS) is created. 08Kh18N10T steel samples had two variants of thermal treatment: 1) 1200 deg (5 h), 600 deg (50 h); 2) 1200 deg (5 h). Methods of non-destructive automated control of 18-10-type steel inclination to IGC are developed on the basis of potentiodynamic reactivation (PR) principle. Automated testing complex is developed, which has undergone experimental running and demonstrated a high confidence of results, reliability and easy operation

Formation of an 18R long-period stacking ordered structure in rapidly solidified Mg88Y8Zn4 alloy

International Nuclear Information System (INIS)

Garcés, Gerardo; Requena, Guillermo; Tolnai, Domonkos; Pérez, Pablo; Medina, Judit; Stark, Andreas; Schell, Norbert; Adeva, Paloma

2016-01-01

The formation of the long-period stacking ordered structure (LPSO) in a Mg 88 Y 8 Zn 4 (at%) ribbon produced by melt spinning was studied using high energy X-ray synchrotron radiation diffraction during in-situ isochronal heating and transmission electron microscopy. The microstructure of the rapidly solidified ribbons is characterised by fine magnesium grains with yttrium and zinc in solid solution and primary 18R LPSO-phase segregated at grain boundaries. Using differential scanning calorimetry, a strong exothermal peak was observed around 300 °C which was associated with the development of the 18R-type LPSO-phase in the magnesium grains. The apparent activation energy calculated using the Kissinger model was 125 KJmol −1 and it is related to simultaneous diffusion of Y and Zn through magnesium basal plane. - Highlights: •The formation of the LPSO phase in rapidly solidified ribbons was studied. •The formation of the 18R LPSO starts at around 300 °C. •LPSO formation have to steps: Stacking faults along basal plane and then growth of 18R structure along the c direction.

Fatigue behaviour of friction welded medium carbon steel and austenitic stainless steel dissimilar joints

International Nuclear Information System (INIS)

Paventhan, R.; Lakshminarayanan, P.R.; Balasubramanian, V.

2011-01-01

Research highlights: → Fusion welding of dissimilar metals is a problem due to difference in properties. → Solid state welding process such as friction welding is a solution for the above problem. → Fatigue life of friction welded carbon steel and stainless steel joints are evaluated. → Effect of notch on the fatigue life of friction welded dissimilar joints is reported. → Formation of intermetallic is responsible for reduction in fatigue life of dissimilar joints. -- Abstract: This paper reports the fatigue behaviour of friction welded medium carbon steel-austenitic stainless steel (MCS-ASS) dissimilar joints. Commercial grade medium carbon steel rods of 12 mm diameter and AISI 304 grade austenitic stainless steel rods of 12 mm diameter were used to fabricate the joints. A constant speed, continuous drive friction welding machine was used to fabricate the joints. Fatigue life of the joints was evaluated conducting the experiments using rotary bending fatigue testing machine (R = -1). Applied stress vs. number of cycles to failure (S-N) curve was plotted for unnotched and notched specimens. Basquin constants, fatigue strength, fatigue notch factor and notch sensitivity factor were evaluated for the dissimilar joints. Fatigue strength of the joints is correlated with microstructure, microhardness and tensile properties of the joints.

Water requirements of the iron and steel industry

Science.gov (United States)

Walling, Faulkner B.; Otts, Louis Ethelbert

1967-01-01

Twenty-nine steel plants surveyed during 1957 and 1958 withdrew from various sources about 1,400 billion gallons of water annually and produced 40.8 million tons of ingot steel. This is equivalent to about 34,000 gallons of water per ton of steel. Fifteen iron ore mines and fifteen ore concentration plants together withdrew annually about 89,000 million gallons to produce 15 million tons of iron ore concentrate, or 5,900 gallons per ton of concentrate. About 97 percent of the water used in the steel plants came from surface sources, 2.2 percent was reclaimed sewage, and 1.2 percent was ground water. Steel plants supplied about 96 percent of their own water requirements, although only three plants used self-supplied water exclusively. Water used by the iron ore mines and concentration plants was also predominantly self supplied from surface source. Water use in the iron and steel industry varied widely and depended on the availability of water, age and condition of plants and equipment, kinds of processes, and plant operating procedures. Gross water use in integrated steel plants ranged from 11,200 to 110,000 gallons per ton of steel ingots, and in steel processing plants it ranged from 4,180 to 26,700 gallons per ton. Water reuse also varied widely from 0 to 18 times in integrated steel plants and from 0 to 44 times in steel processing plants. Availability of water seemed to be the principal factor in determining the rate of reuse. Of the units within steel plants, a typical (median) blast furnace required 20,500 gallons of water per ton of pig iron. At the 1956-60 average rate of pig iron consumption, this amounts to about 13,000 gallons per ton of steel ingots or about 40 percent of that required by a typical integrated steel plant 33,200 gallons per ton. Different processes of iron ore concentration are devised specifically for the various kinds of ore. These processes result in a wide range of water use from 124 to 11,300 gallons of water per ton of iron ore

Tribological properties and surface structures of ion implanted 9Cr18Mo stainless steels

Science.gov (United States)

Fengbin, Liu; Guohao, Fu; Yan, Cui; Qiguo, Sun; Min, Qu; Yi, Sun

2013-07-01

The polished quenched-and-tempered 9Cr18Mo steels were implanted with N ions and Ti ions respectively at a fluence of 2 × 1017 ions/cm2. The mechanical properties of the samples were investigated by using nanoindenter and tribometer. The results showed that the ion implantations would improve the nanohardness and tribological property, especially N ion implantation. The surface analysis of the implanted samples was carried out by using XRD, XPS and AES. It indicated that the surface exhibits graded layers after ion implantation. For N ion implantation, the surface about 20 nm thickness is mainly composed of supersaturated interstitial N solid solution, oxynitrides, CrxCy phase and metal nitrides. In the subsurface region, the metal nitrides dominate and the other phases disappear. For Ti ion implantation, the surface of about 20 nm thickness is mainly composed of titanium oxides and carbon amorphous phase, the interstitial solid solution of Ti in Fe is abundant in the subsurface region. The surface components and structures have significant contributions to the improved mechanical properties.

Tribological properties and surface structures of ion implanted 9Cr18Mo stainless steels

International Nuclear Information System (INIS)

Fengbin, Liu; Guohao, Fu; Yan, Cui; Qiguo, Sun; Min, Qu; Yi, Sun

2013-01-01

The polished quenched-and-tempered 9Cr18Mo steels were implanted with N ions and Ti ions respectively at a fluence of 2 × 10 17 ions/cm 2 . The mechanical properties of the samples were investigated by using nanoindenter and tribometer. The results showed that the ion implantations would improve the nanohardness and tribological property, especially N ion implantation. The surface analysis of the implanted samples was carried out by using XRD, XPS and AES. It indicated that the surface exhibits graded layers after ion implantation. For N ion implantation, the surface about 20 nm thickness is mainly composed of supersaturated interstitial N solid solution, oxynitrides, Cr x C y phase and metal nitrides. In the subsurface region, the metal nitrides dominate and the other phases disappear. For Ti ion implantation, the surface of about 20 nm thickness is mainly composed of titanium oxides and carbon amorphous phase, the interstitial solid solution of Ti in Fe is abundant in the subsurface region. The surface components and structures have significant contributions to the improved mechanical properties

Measurement of high temperature elastic moduli of an 18Cr-9Ni-2.95 Cu-0.58 Nb-0.1C (Wt %) austenitic stainless steel

Science.gov (United States)

Tripathy, Haraprasanna; Hajra, Raj Narayan; Sudha, C.; Raju, S.; Saibaba, Saroja

2018-04-01

The Young's modulus (E) and Shear modulus (G) of an indigenously developed 18Cr-9Ni-0.1C-2.95 Cu-0.58Nb (wt %) austenitic stainless steel has been evaluated in the temperature range 298 K to 1273 K (25 °C to 1000 °C), using Impulse excitation technique (IET). The Bulk modulus (K) and the poison's ratio have been estimated from the measured values of E and G. It is observed that the elastic constants (E, G and K) are found to decrease in a nonlinear fashion with increase in temperature. The Cu precipitation is found to influence the elastic moduli of the steel in the cooling cycle. The observed elastic moduli are fitted to 3rd order polynomial equations in order to describe the temperature dependence of E, G, K moduli in the temperature range 298-1273 K (25 °C to 1000 °C). The room temperature values of E,G and K moduli is found to be 207, 82 and 145 GPa respectively for the present steel.

Influence of titanium on the tempering structure of austenitic steels

International Nuclear Information System (INIS)

Ghuezaiel, M.J.

1985-10-01

The microstructure of titanium-stabilized and initially deformed (approximately 20%) austenitic stainless steels used in structures of fast neutrons reactors has been studied after one hour duration annealings (500 0 C) by X-ray diffraction, optical microscopy, microhardness and transmission electron microscopy. The studied alloys were either of industrial type CND 17-13 (0.23 to 0.45 wt% Ti) or pure steels (18% Cr, 14% Ni, 0 or 0.3 wt% Ti). During tempering, the pure steels presented some restauration before recristallization. In the industrial steels, only recristallization occurred, and this only in the most deformed steel. Precipitation does not occur in the titanium-free pure steel. In industrial steels, many intermetallic phases are formed when recristallization starts [fr

Influence of quantity of non-martensite products of transformation on resistance to fracture of improving structural steel

International Nuclear Information System (INIS)

Gulyaev, A.P.; Golovanenko, Yu.S.; Zikeev, V.N.

1978-01-01

18KhNMFA, low-carbon, alloyed steel and 42KhMFA medium-carbon, alloyed steel have been examined. For the purpose of obtaining different structures in hardening the steel, different cooling rates, different temperatures and isothermal holding times are applied. The following has been shown: on tempering to the same hardness (HV 300), the presence of non-martensite structures in hardened state does not practically influence the standard mechanical properties of steel (sigmasub(B), sigmasub(0.2), delta, PSI). The resistance of steel to the brittle failure is enhanced by the uniform, fine-disperse distribution of the carbide phase in the structure of lower bainite (up to 80 % bainite in martensite for 42KhMF steel to be improved), as well as strongly fragmented packages of rack martensite-bainite (up to 50 % lower bainite in martensite of 18KhNMFA steel). The formation of the upper bainite in the structure of the hardened steels 18KhNMFA and 42KhMF results on tempering in the formation of coarse, non-uniform, branched carbide inclusions, and this, in its turn, leads to raising the cold-shortness threshold and to lowering the amount of work as required for propagation of a crack. The presence of ferritic-pearlitic structures in the structural steels hardened to martensite and bainite results in reducing the resistance of steel to the brittle failure; the presence of every 10 % ferritic-pearlitic component in martensite of the structural steels 18KhNMFA and 42KhMFA to be thermally improved, raises T 50 by 8 deg and 20 deg C, respectively

A Critical Analysis of Grain-Size and Yield-Strength Dependence of Near-Threshold Fatigue-Crack Growth in Steels.

Science.gov (United States)

1981-07-15

of high-strength steel ), and a host of microstructural types (ferritic, martensitic, pearlitic, bainitic , austenitic). Accession For NTIS GRA&l DTIC...IN STEELS , : RPRNGO.RPRTNMR 1~A Tw.R CONTRACT OA4A&XMUt8~ G/~ ! R./koderl L.A./Cooleyad T.W./Crooker 2 .{I 9PERFORMING ORGANIZATION NAME AND A10R4SI...growth Steels Microstructure Ferrous alloys Structure-sensitive crack growth 20 ABSTRACT (Con~tinue an r*,er.. side it necesar and Identity by black

[Studies on the tolerance of the organism to X 5 CrNiMo 18.10 steel (Königsee). II. Light microscopic studies of the surrounding tissue of metal implants (X 5 CrNiMo 18.10 steel) in guinea pigs].

Science.gov (United States)

Höhndorf, H; Drössler, K; Stiehl, P

1977-06-01

The tissue around X 5 CrNiMo 18.10-steel implantates with different surfaces was examined in 72 guinea-pigs. Aside from controls, these animals were preoperatively sensibilized against chromium and nickel. The results can be summarized since the histologic findings showed no different peculiarities. The authors describe an intussusception of the implantate in connective tissue which evidently depends on time and surface. Further the spreading of alien material in the surrounding of the implantate, and morphologic findings are reported. The morphologic evidences are described and discussed in detail, since they are interpreted as signs of cell-mediated immune reactions. The presence of lymphocytes, lymphoblasts, histiocytes (mostly carrying alien material), and granulocytes, as well as proliferations at the arterioles suggest an overlapping of immune reactions.

Study of the damage processes induced by thermal fatigue in stainless steels F17TNb and R20-12 for automobile application; Etude de l'endommagement en fatigue thermique des aciers inoxydables F17TNb et R20-12 pour application automobile

Energy Technology Data Exchange (ETDEWEB)

Bucher, L.

2004-12-15

Thermal cycling is the main cause of fatigue failure in automobile exhaust manifolds for which the use of stainless steel now rivals that of cast iron which has been traditionally used. An original fatigue test has been developed by Ugine and ALZ, a stainless steel producer, so as to be able to compare different grades of stainless steel alloys. This test is representative of the thermal conditions encountered in the critical zones of exhaust manifolds. However, it has revealed significant differences in damage processes in the ferritic and austenitic grades tested. The subject of this thesis is the damage processes induced by thermal fatigue in stainless steels used for automotive exhaust manifolds. Two stainless steels were studied: a ferritic grade, F17TNb (17%Cr and stabilized with Ti and Nb), and an austenitic grade, R20-12, containing 20% Cr and 12% Ni. The first objective was to understand the different damage processes induced by thermal fatigue in the ferritic and austenitic grades. The second was to develop a numerical design tool of the thermally tested structures. (author)

Effect of aging on the tribological and mechanical properties of a high-nitrogen stainless austenitic steel

International Nuclear Information System (INIS)

Korshunov, L.G.; Chernenko, N.L.; Tereshchenko, N.A.; Uvarov, A.I.

2005-01-01

The effect of aging, associated with predominant precipitation of vanadium nitrides (VN), on tribological and mechanical properties of austenitic steel 10Kh18AG18N5MF hardened from 1100 Deg C is studied. Metallographic, X-ray diffraction and electron microscopical methods are used to study structural transformations proceeding in the steel on aging as well as on friction loading under conditions of dry slipping friction in steel-abrasive and steel-steel pairs. It is shown that the aging at temperatures of 600-700 Deg C resulting in a considerable increase of strength properties of the steel demonstrates a relatively weak positive effect on steel resistance to abrasive and adhesive wear. It is stated that the use of aging by continuous mechanism permits attaining favourable mechanical and tribological properties in vanadium-alloying nitrogen-bearing austenitic steels [ru

Effect of nitrogen on the stabilization of austenite in a tungsten-molybdenum high-speed steel

International Nuclear Information System (INIS)

Popandopulo, A.N.; Zhukova, L.T.

1986-01-01

A study was made of the tendency of steels R6M5 and R6Am5 to austenite stabilization after subzero treatment and high-temperature tempering in hot-rolled bars. Data indicate that in steel R6AM5 during quenching there is almost instantaneous austenite stabilization. The data was derived from a study of phase composition (exposure from a microsection in DRON-2.0 equipment in iron K /SUB alpha/ radiation), microstructure, and hardness. The authors conclude that in view of serious difficulties in metallurgical and tool production, steel R6AM5 should be supplied only at the request of the customer

Structural Characterization of Highly Corrosion-resistant Steel

Czech Academy of Sciences Publication Activity Database

Lančok, Adriana; Kmječ, T.; Štefánik, M.; Sklenka, L.; Miglierini, M.

2015-01-01

Roč. 88, č. 4 (2015), s. 355-361 ISSN 0011-1643 R&D Projects: GA ČR(CZ) GA14-12449S Institutional support: RVO:61388980 Keywords : Mossbauer spectroscopy * corrosion-resistant steel * LC200 * CEMS Subject RIV: CA - Inorganic Chemistry Impact factor: 0.732, year: 2015

The comparison of 18C(n; γ)19C and 18C(α; n)21O reaction rates: consequences for the r-process

International Nuclear Information System (INIS)

Dan, M.; Singh, G.; Chatterjee, R.; Shubhchintak

2017-01-01

Neutron rich light and medium mass nuclei play a major role in determining the reaction flow towards the r-process seed nuclei production. In this text, we calculate the neutron capture rate of 18 C and compare it with that of α-capture by the same nucleus in the temperature range T 9 = 0:1 - 10. This temperature range roughly equals to an energy range of 1 keV to 1 MeV in centre of mass frame, where it is very difficult to perform direct reaction experiments. Further, the theoretical construction of 18 C-n continuum state for the 18 C(n; γ) 19 C direct reaction is a tedious job

Cooperation on impingement wastage experiment of Mod. 9Cr-1Mo steel using SWAT-1R sodium-water reaction test facility

International Nuclear Information System (INIS)

Beauchamp, F.; Allou, A.; Nishimura, M.; Umeda, R.

2013-01-01

Conclusion: • 6 experiments were carried out in the SWAT-1R facility of JAEA Oarai R&D Center to study the wastage resistance of the Mod. 9Cr-1Mo steel (T91) straight tubes. • These experiments were performed under the cooperation between CEA and JAEA. • The experiments were conducted successfully: - all the tubes were punctured by the reaction jet, - wastage and steam/water leak rates were obtained, - experimental results brought some new determining sets of wastage data on T91. • This fruitful cooperation has contributed to: - expanding the wastage database on T91, - upgrading wastage rates prediction from modelling, - the safety demonstration of future steam generators units

Performance of Retrofitted Self-Compacting Concrete-Filled Steel Tube Beams Using External Steel Plates

Directory of Open Access Journals (Sweden)

Ahmed A. M. AL-Shaar

2018-01-01

Full Text Available Self-compacting concrete-filled steel tube (SCCFST beams, similar to other structural members, necessitate retrofitting for many causes. However, research on SCCFST beams externally retrofitted by bolted steel plates has seldom been explored in the literature. This paper aims at experimentally investigating the retrofitting performance of square self-compacting concrete-filled steel tube (SCCFST beams using bolted steel plates with three different retrofitting schemes including varied configurations and two different steel plate lengths under flexure. A total of 18 specimens which consist of 12 retrofitted SCCFST beams, three unretrofitted (control SCCFST beams, and three hollow steel tubes were used. The flexural behaviour of the retrofitted SCCFST beams was examined regarding flexural strength, failure modes, and moment versus deflection curves, energy absorption, and ductility. Experimental results revealed that the implemented retrofitting schemes efficiently improve the moment carrying capacity and stiffness of the retrofitted SCCFST beams compared to the control beams. The increment in flexural strength ranged from 1% to 46%. Furthermore, the adopted retrofitting schemes were able to restore the energy absorption and ductility of the damaged beams in the range of 35% to 75% of the original beam ductility. Furthermore, a theoretical model was suggested to predict the moment capacity of the retrofitted SCCFST beams. The theoretical model results were in good agreement with the test results.

Anodized Steel Electrodes for Supercapacitors.

Science.gov (United States)

Sagu, Jagdeep S; Wijayantha, K G Upul; Bohm, Mallika; Bohm, Siva; Kumar Rout, Tapan

2016-03-09

Steel was anodized in 10 M NaOH to enhance its surface texture and internal surface area for application as an electrode in supercapacitors. A mechanism was proposed for the anodization process. Field-emission gun scanning electron microscopy (FEGSEM) studies of anodized steel revealed that it contains a highly porous sponge like structure ideal for supercapacitor electrodes. X-ray photoelectron spectroscopy (XPS) measurements showed that the surface of the anodized steel was Fe2O3, whereas X-ray diffraction (XRD) measurements indicated that the bulk remained as metallic Fe. The supercapacitor performance of the anodized steel was tested in 1 M NaOH and a capacitance of 18 mF cm(-2) was obtained. Cyclic voltammetry measurements showed that there was a large psueudocapacitive contribution which was due to oxidation of Fe to Fe(OH)2 and then further oxidation to FeOOH, and the respective reduction of these species back to metallic Fe. These redox processes were found to be remarkably reversible as the electrode showed no loss in capacitance after 10000 cycles. The results demonstrate that anodization of steel is a suitable method to produce high-surface-area electrodes for supercapacitors with excellent cycling lifetime.

Improving composition of protective coatings for steel casting

International Nuclear Information System (INIS)

Kuz'kina, N.N.; Pegov, V.G.; Bogatenkov, V.F.; Shub, L.G.; Raspopova, N.A.

1983-01-01

A radically new fuel-free slag-forming mixture used as protective coating for steel casting is introduced. The lack of combustible powders precludes explosion and fire Lazard in mixture preparation. Usage of the new mixture in stainless steel casting of Kh18N10T type permitted to improve the ingot surface quality and reduce spoilage from 1.16 to 0.66%

Steel for nuclear applications

International Nuclear Information System (INIS)

Zorev, N.N.; Astafiev, A.A.; Loboda, A.S.

1978-01-01

A steel contains, in percent by weight, the following constituents: carbon from 0.13 to 0.18, silicon from 0.17 to 0.37, manganese from 0.30 to 0.60, chromium from 1.7 to 2.4, nickel from 1.0 to 1.5, molybdenum from 0.5 to 0.7, vanadium from 0.05 to 0.12, aluminium from 0.01 to 0.035, nitrogen from 0.05 to 0.012, copper from 0.11 to 0.20, arsenic from 0.0035 to 0.0055, iron and impurities, the balance. This steel is preferable for use in the manufacture of nuclear reactors. 1 table

X-ray diffraction study of slags forming during corrosion resistant steel production

International Nuclear Information System (INIS)

Slavov, V.I.; Zadorozhnaya, V.N.; Shurygina, A.V.

1990-01-01

Using X-ray diffraction analysis slags, forming during corrosion-resistant 12Kh18N10T grade steel production by two flowsheets, are studied. Standard two-slag technology of steel production does not provide efficient disintegration of chromospinelides in slags, gives high steel contamination with respect to nonmetallic impurities, coarse structure and, as a consequence, presence of macrodefects on rolled products surface. One-slag steel melting technology with titanium alloying of the steel at vacuum causes fast removal of chromospinelides at the beginning of reduction period, promotes titanium absorption by the steel, refines nonmetallic inclusions, provides more fine structure and steel plasticity, removes surface defects

Ferritic stainless steels: corrosion resistance + economy

International Nuclear Information System (INIS)

Remus, A.L.

1976-01-01

Ferritic stainless steels provide corrosion resistance at lower cost. They include Type 409, Type 439, 18SR, 20-Mo (1.6 Mo), 18-2 (2 Mo), 26-1S, E-Brite 26-1, 29 Cr-4 Mo, and 29 Cr-4 Mo-2 Ni. Their corrosion and mechanical properties are examined. Resistance to stress-corrosion cracking is an advantage compared to austenitic types

Analysis of Helical Stainless Steel 08X18H10 Spring Relaxation at High Temperature

Directory of Open Access Journals (Sweden)

H. Sun

2015-01-01

Full Text Available The object of this paper is to study a cylindrical helical spring to be applied at high temperatures. The aim of this work is to study the regularity of relaxation stresses in spring and evaluate its long-term stresses.The work allowed us to establish relaxation dependencies of springs under high temperatures. According to the results of creep tests at 600°, the theoretical equation of steel creep was defined concretely. It was then used for the analysis at 350°.The paper presents a created finite element model of spring relaxation. It is the stainless steel 08Х18Н10 spring to be used at the temperature of 350°.In this paper describes the basic theory of creep, considers the relationship between the creep speed and parameters. The changing compression force of springs is analyzed under fixed compression amount.The paper also analyzes the changing length of springs in the free state after various stages of high-temperature relaxation test. It determines the results of compression forces and free length under different amount of compression.The analysis to compare the theoretical calculation of the compression forces with the experimental results is conducted. Computer modeling is created in Abaqus for calculation. Spring relaxation experiments are carried out under fixed compression amount and at the temperature of 350°. It is shown that the simulation results, which are carried out in Abaqus coincide with experimental results. The study shows that it is possible to use the creep equation parameters, based on the experimental results at high temperatures, to predict creep and relaxation properties of springs, which work at less high temperatures. The work results can be used as a basis in designing the springs working at high temperatures.

Aging degradation of cast stainless steel

International Nuclear Information System (INIS)

Chopra, O.K.; Chung, H.M.

1985-10-01

A program is being conducted to investigate the significance of in-service embrittlement of cast-duplex stainless steels under light-water reactor operating conditions. Data from room-temperature Charpy-impact tests for several heats of cast stainless steel aged up to 10,000 h at 350, 400, and 450 0 C are presented and compared with results from other studies. Microstructures of cast-duplex stainless steels subjected to long-term aging either in the laboratory or in reactor service have been characterized. The results indicate that at least two processes contribute to the low-temperature embrittleent of duplex stainless steels, viz., weakening of the ferrite/austenite phase boundary by carbide precipitation and embrittlement of ferrite matrix by the formation of additional phases such as G-phase, Type X, or the α' phase. Carbide precipitation has a significant effect on the onset of embrittlement of CF-8 and -8M grades of stainless steels aged at 400 or 450 0 C. The existing correlations do not accurately represent the embrittlement behavior over the temperature range 300 to 450 0 C. 18 refs., 13 figs

Estimation of quasi-static J–R curves from Charpy energy and adaptation to ASTM E 1921 reference temperature estimation of ferritic steels

International Nuclear Information System (INIS)

Sreenivasan, P.R.

2014-01-01

Many researchers had suggested a sort of scaling procedure for predicting the quasi-static J–R curves from dynamic J–R curves obtained from instrumented Charpy V-notch (CVN) impact tests using key-curve, compliance or other procedures. Chaouadi, based on extensive tests and literature data, had quantitatively formalized the method and suggested general applicability of his method for a class of steels. In this paper, first, the Chauoadi-procedure is tried on some selected data from the literature (including the data used by Chaouadi and other workers) and an adaptation of the method is suggested using Wallin's as well as Landes's lower bound methods for upper-shelf J–R curve estimation from CVN energy. Using Chaouadi and other data as the benchmark, suitable scaling factors have been determined that enable estimation of quasi-static J–R curves from CVN energy alone, without the need for dynamic CVN J–R curves. The final formulae are given. This new method can be called modified Wallin–Landes procedure. Then this method is applied to fracture toughness and reference temperature (T 0 – ASTM E-1921) estimation from the full Charpy-transition data. The results are compared with those from the author's IGC-procedure, and modifications, if any, are suggested. Based on the new results, it is suggested that the IGC-procedure may be modified as: final T Q-est = T Q-IGC for T Q-Sch dy ≤ 20 °C (in the IGC-procedure the dividing temperature was 60 °C); and for T Q-Sch dy > 20 °C, T Q-IGC = T Q-WLm (different from the IGC-procedre and subscript WLm indicating modified Wallin–Landes procedure). For the 59 or more steels examined (including highly irradiated steels), the T Q-WL estimates at higher temperatures are consistent and conservative; a few non-conservative values are acceptably less than 20 °C, whereas other predictions show non-conservatism of up to 40–50 °C. At lower temperatures, T Q-IGC is consistently conservative and not over

Estimation of quasi-static J–R curves from Charpy energy and adaptation to ASTM E 1921 reference temperature estimation of ferritic steels

Energy Technology Data Exchange (ETDEWEB)

Sreenivasan, P.R., E-mail: sreeprs@yahoo.co.in

2014-04-01

Many researchers had suggested a sort of scaling procedure for predicting the quasi-static J–R curves from dynamic J–R curves obtained from instrumented Charpy V-notch (CVN) impact tests using key-curve, compliance or other procedures. Chaouadi, based on extensive tests and literature data, had quantitatively formalized the method and suggested general applicability of his method for a class of steels. In this paper, first, the Chauoadi-procedure is tried on some selected data from the literature (including the data used by Chaouadi and other workers) and an adaptation of the method is suggested using Wallin's as well as Landes's lower bound methods for upper-shelf J–R curve estimation from CVN energy. Using Chaouadi and other data as the benchmark, suitable scaling factors have been determined that enable estimation of quasi-static J–R curves from CVN energy alone, without the need for dynamic CVN J–R curves. The final formulae are given. This new method can be called modified Wallin–Landes procedure. Then this method is applied to fracture toughness and reference temperature (T{sub 0} – ASTM E-1921) estimation from the full Charpy-transition data. The results are compared with those from the author's IGC-procedure, and modifications, if any, are suggested. Based on the new results, it is suggested that the IGC-procedure may be modified as: final T{sub Q-est} = T{sub Q-IGC} for T{sub Q-Sch}{sup dy} ≤ 20 °C (in the IGC-procedure the dividing temperature was 60 °C); and for T{sub Q-Sch}{sup dy} > 20 °C, T{sub Q-IGC} = T{sub Q-WLm} (different from the IGC-procedre and subscript WLm indicating modified Wallin–Landes procedure). For the 59 or more steels examined (including highly irradiated steels), the T{sub Q-WL} estimates at higher temperatures are consistent and conservative; a few non-conservative values are acceptably less than 20 °C, whereas other predictions show non-conservatism of up to 40–50 °C. At lower temperatures

Application of the EPR technique in welded couplings in 08X18H10T (AISI 321) stainless steel

International Nuclear Information System (INIS)

Fuentes, D.A.; Menendez, C.M.; Dominguez, H.; Sendoya, F.

1993-01-01

Stainless steel samples, one AISI 304 and the other 08X18H10T of Soviet origin (equivalent to AISI 320) were welded for the TIG method, submitted to a thermal treatment in order to its sensitization against the intergranular corrosion, then the samples were submitted to the EPR technique in order to establish the sensitization degree which is an indicative of susceptibility to intergranular corrosion. The result were corroborated by two different methodologies, the ASTM A262 standard and the soviet standard GOST 6032-89. The state of the tested surface was analyzed using optical microscopy in order to quantify the number of pricking since its presence disturbs the normalized charge, Pa. (Author)

Effect of helium ion bombardment on hydrogen behaviour in stainless steel

International Nuclear Information System (INIS)

Guseva, M.I.; Stolyarova, V.G.; Gorbatov, E.A.

1987-01-01

The effect of helium ion bombardment on hydrogen behaviour in 12Kh18N10T stainless steel is investigated. Helium and hydrogen ion bombardment was conducted in the ILU-3 ion accelerator; the fluence and energy made up 10 16 -5x10 17 cm -2 , 30 keV and 10 16 -5x10 18 cm -2 , 10 keV respectively. The method of recoil nuclei was used for determination of helium and hydrogen content. Successive implantation of helium and hydrogen ions into 12Kh18N10T stainless steel results in hydrogen capture by defects formed by helium ions

A methodology for replacement of conventional steel by microalloyed steel in bus tubular structures

International Nuclear Information System (INIS)

Cruz, Magnus G.H.; Viecelli, Alexandre

2008-01-01

The aim of this article is to show the use of a methodology that allows, in a trustful way and without the need to build up a complete physical model, the replacement of conventional steel by structural microalloyed steel (HSLA) in tubular structure, concerning passengers transport in vehicles with capacity of more than 20 people. The validation of the methodology is based on the ECE R66-00 regulation and on the Brazilian CONTRAN 811/96 resolution, which regulate minimal conditions of safety for this kind of vehicle. The methodology has four sequential and dependent stages, where the main focus is related to the experimental tests through the models that are simplified initially for later calibration using finite element method. Modular structures made of two different materials were tested and analyzed to confirm the present methodology, first the structure made of steel that is used by the bus industry in Brazil was tested and then it was compared with the new microalloyed steel. Experimental values are compared with calculated ones, foreseeing parametric optimisation and keeping the security levels according to legislation

A methodology for replacement of conventional steel by microalloyed steel in bus tubular structures

Energy Technology Data Exchange (ETDEWEB)

Cruz, Magnus G.H. [Marcopolo S.A., Unidade Ana Rech, Av. Rio Branco, 4889, Ana Rach, 95060-650 Caxias do Sul (Brazil)], E-mail: magnus@verbonet.com.br; Viecelli, Alexandre [Mechanical Engineering Department, Universidade de Caxias do Sul, Rua Francisco Getulio Vargas, 1130, 95070-560 Caxias do Sul, RS (Brazil)], E-mail: avieceli@ucs.br

2008-07-01

The aim of this article is to show the use of a methodology that allows, in a trustful way and without the need to build up a complete physical model, the replacement of conventional steel by structural microalloyed steel (HSLA) in tubular structure, concerning passengers transport in vehicles with capacity of more than 20 people. The validation of the methodology is based on the ECE R66-00 regulation and on the Brazilian CONTRAN 811/96 resolution, which regulate minimal conditions of safety for this kind of vehicle. The methodology has four sequential and dependent stages, where the main focus is related to the experimental tests through the models that are simplified initially for later calibration using finite element method. Modular structures made of two different materials were tested and analyzed to confirm the present methodology, first the structure made of steel that is used by the bus industry in Brazil was tested and then it was compared with the new microalloyed steel. Experimental values are compared with calculated ones, foreseeing parametric optimisation and keeping the security levels according to legislation.

The crack growth resistance of thin steel sheets under eccentric ...

Indian Academy of Sciences (India)

Ľ AMBRIŠKO

2018-03-10

Mar 10, 2018 ... of zinc-coated automotive steel sheets (IF – deep drawing interstitial free steel ..... to determine; therefore, the Ji was determined for observ- able crack initiation .... M R S, da Silva L F M and de Castro P M S T 2011. Analysis of ...

Effect of nickel chloride on Arabidopsis genomic DNA and methylation of 18S rDNA

Directory of Open Access Journals (Sweden)

Zhongai Li

2015-01-01

Conclusions: NiCl2 application caused variation of DNA methylation of the Arabidopsis genomic and offspring's. NiCl2 also resulted in nucleolar injury and deformity of root tip cells. The methylation rate of 18S rDNA also changed by adding NiCl2.

Effect of copper, tin, phosphorous and arsenic on the surface cracking of a 18-8 stainless steel during hot compression tests

International Nuclear Information System (INIS)

Botella, J.; Fernandez, M.T.; Fernandez de Castillo, I.

1998-01-01

The effect of certain different concentrations of Cu, Sn, P and As on the surface cracking of 18-8 austenitic stainless steel hot compressed specimens has been studied, at 1,123 and 1,273 K, in an oxidizing atmosphere (air). A procedure for determining surface cracking has been established, and the cracking factor obtained in this ways is correlated with the chemical composition of the materials at both temperatures. The cracking factors obtained at 1,273 K have been compared with the reduction of area drops obtained by hot tension tests at the same temperature. (Author) 5 refs

Resistance to pitting corrosion in ferritic and austenitic/ferritic steels

International Nuclear Information System (INIS)

De Bouvier, O.

1995-01-01

Stainless steel tubes carrying raw water are potentially vulnerable to pitting corrosion. With a view to minimizing the corrosion risk in the river-water-cooled condensers at PWR power plant, a study was conducted to determine initiation conditions and incubation durations for pitting corrosion in stagnant water. As a result, condenser tubes in Z2 CI 18 (439) or Z2 CT 18-10 (304L) steels were phased out in favour of Z2 CND 16-32 (316L) stainless steel. The same question can be yield for other applications and especially for all types of exchangers for use in electrical applications. This study sought to assess alternative methods for estimating pitting corrosion, and to check the results of these methods against the actual behaviour of studied steels. The study covered ferritic steels (439, 444, 290Mo), austenitic steel (316L) and austenitic/ferritic steels (Uranus 35N, 45N, 47N, 52N). Two approaches were adopted: laboratory tests to compare pitting corrosion risks on different materials, and tests for characterizing the behaviour of steels exposed to river water. The study begins with a laboratory tests that yield an arbitrary parameter for quantifying pitting corrosion resistance. One method involves measuring the pitting temperature in an aggressive ferric chloride solution. Other methods measure the pitting potential, either statistically (Multipit method) or deterministically (polarization curve). We then go on to discuss tests under simulated life-like conditions, involving repeated immersions in water from the Seine. (author). 9 refs., 13 figs, 9 tabs

SU-F-R-13: Decoding 18F-FDG Uptake Heterogeneity for Primary and Lymphoma Tumors by Using Texture Analysis in PET Images

Energy Technology Data Exchange (ETDEWEB)

Ma, C; Yin, Y [Shandong Cancer Hospital and Institute, Jinan, Shandong (China)

2016-06-15

Purpose: To explore 18F-FDG uptake heterogeneity of primary tumor and lymphoma tumor by texture features of PET image and quantify the heterogeneity difference between primary tumor and lymphoma tumor. Methods: 18 patients with primary tumor and lymphoma tumor in lung cancer were enrolled. All patients underwent whole-body 18F-FDG PET/CT scans before treatment. Texture features, based on Gray-level Co-occurrence Matrix, second and high order matrices are extracted from code using MATLAB software to quantify 18F-FDG uptake heterogeneity. The relationships of volume between energy, entropy, correlation, homogeneity and contrast were analyzed. Results: For different cases, tumor heterogeneity was not the same. Texture parameters (contrast, entropy, and correlation) of lymphoma were lower than primary tumor. On the contrast, the texture parameters (energy, homogeneity and inverse different moment) of lymphoma were higher than primary tumor. Significantly, correlations were observed between volume and energy (primary, r=−0.194, p=0.441; lymphoma, r=−0.339, p=0.582), homogeneity (primary, r=−0.146, p=0.382; lymphoma, r=−0.193, p=0.44), inverse difference moment (primary, r=−0.14, p=0.374; lymphoma, r=−0.172, p=0.414) and a positive correlation between volume and entropy (primary, r=0.233, p=0.483; lymphoma, r=0.462, p=0.680), contrast (primary, r=0.159, p=0.399; lymphoma, r=0.341, p=0.584), correlation (primary, r=0.027, p=0.165; lymphoma, r=0.046, p=0.215). For the same patient, energy for primary and lymphoma tumor is equal. The volume of lymphoma is smaller than primary tumor, but the homogeneity were higher than primary tumor. Conclusion: This study showed that there were effective heterogeneity differences between primary and lymphoma tumor by FDG-PET image texture analysis.

SU-F-R-13: Decoding 18F-FDG Uptake Heterogeneity for Primary and Lymphoma Tumors by Using Texture Analysis in PET Images

International Nuclear Information System (INIS)

Ma, C; Yin, Y

2016-01-01

Purpose: To explore 18F-FDG uptake heterogeneity of primary tumor and lymphoma tumor by texture features of PET image and quantify the heterogeneity difference between primary tumor and lymphoma tumor. Methods: 18 patients with primary tumor and lymphoma tumor in lung cancer were enrolled. All patients underwent whole-body 18F-FDG PET/CT scans before treatment. Texture features, based on Gray-level Co-occurrence Matrix, second and high order matrices are extracted from code using MATLAB software to quantify 18F-FDG uptake heterogeneity. The relationships of volume between energy, entropy, correlation, homogeneity and contrast were analyzed. Results: For different cases, tumor heterogeneity was not the same. Texture parameters (contrast, entropy, and correlation) of lymphoma were lower than primary tumor. On the contrast, the texture parameters (energy, homogeneity and inverse different moment) of lymphoma were higher than primary tumor. Significantly, correlations were observed between volume and energy (primary, r=−0.194, p=0.441; lymphoma, r=−0.339, p=0.582), homogeneity (primary, r=−0.146, p=0.382; lymphoma, r=−0.193, p=0.44), inverse difference moment (primary, r=−0.14, p=0.374; lymphoma, r=−0.172, p=0.414) and a positive correlation between volume and entropy (primary, r=0.233, p=0.483; lymphoma, r=0.462, p=0.680), contrast (primary, r=0.159, p=0.399; lymphoma, r=0.341, p=0.584), correlation (primary, r=0.027, p=0.165; lymphoma, r=0.046, p=0.215). For the same patient, energy for primary and lymphoma tumor is equal. The volume of lymphoma is smaller than primary tumor, but the homogeneity were higher than primary tumor. Conclusion: This study showed that there were effective heterogeneity differences between primary and lymphoma tumor by FDG-PET image texture analysis.

Low-Cycle Fatigue Behaviour of AISI 18Ni300 Maraging Steel Produced by Selective Laser Melting

Directory of Open Access Journals (Sweden)

Ricardo Branco

2018-01-01

Full Text Available Selective laser melting has received a great deal of attention in recent years. Nevertheless, research has been mainly focused on the technical issues and their relationship with the final microstructure and monotonic properties. Fatigue behaviour has rarely been addressed, and the emphasis has been placed on high-cycle regimes. The aim of this paper is, therefore, to study, in a systematic manner, the cyclic plastic behaviour of AISI 18Ni300 maraging steel manufactured by selective laser melting. For this purpose, low-cycle fatigue tests, under fully-reversed strain-controlled conditions, with strain amplitudes ranging from 0.3% to 1.0%, were performed. After testing, fracture surfaces were examined by scanning electron microscopy to identify the main fatigue damage mechanisms. The analysis of results showed a non-Masing material, with a slight strain-softening behaviour, and non-linear response in both the elastic and plastic regimes. In addition, this steel exhibited a very low transition life of about 35 reversals, far below the values of conventional materials with equivalent monotonic mechanical properties, which can be attributed to the combination of high strength and low ductility. The total strain energy density, irrespective of strain amplitude, revealed itself to be a quite stable parameter throughout the lifetime. Finally, the SEM analysis showed for almost all the tested samples cracks initiated from the surface and inner defects which propagated through the rest of the cross section. A ductile/brittle fracture, with a predominance of brittle fracture, was observed in the samples, owing to the presence of defects which make it easier to spread the microcracks.

miR-18a promotes cell proliferation of esophageal squamous cell carcinoma cells by increasing cylin D1 via regulating PTEN-PI3K-AKT-mTOR signaling axis

Energy Technology Data Exchange (ETDEWEB)

Zhang, Weiguo, E-mail: weiguozhangHU@gmail.com; Lei, Caipeng; Fan, Junli; Wang, Jing

2016-08-12

Esophageal squamous cell carcinoma (ESCC) is one of the lethal cancers with a high incidence rate in Asia. Cyclin D1 is overexpressed and plays an important role in the carcinogenesis of ESCC; however the mechanism of the deregulation of Cyclin D1 in ESCC remains to be determined. In the study, we found that miR-18a promotes the expression Cyclin D1 by targeting PTEN in eophageal squamous cell carcinoma TE13 and Eca109 cells. Transfection of miR-18a mimetics increased cyclin D1, while transfection of miR-18a antagomir decreased D1. Moreover, miR-18a-mediated upregulation of cyclin D1 was accompanied with downregulation of PTEN, which is a direct target of miR-18a, and increase of the phosphorylation of AKT and S6K1. In addition, pharmacologic inhibition of AKT or mTOR kinases abolished the increase of cyclinD1 by miR-18a, which was accompanied with decreased phosphorylation of Rb−S780 and inhibition of cell proliferation. Our results demonstrated the upregulation of miR-18a promoted cell proliferation by increasing cylin D1 via regulating PTEN-PI3K-AKT-mTOR signaling axis, suggesting that small molecule inhibitors of AKT-mTOR signaling are potential agents for the treatment of ESCC patients with upregulation of miR-17-92 cluster. - Highlights: • miR-18a promotes the proliferation of ESCC cells. • miR-18a increase cyclin D1 expression in ESCC cells. • miR-18a directly targets PTEN in ESCC cells. • Inhibition of AKT-mTOR prevents miR-18a-induced cyclin D1 in ESCC cells. • miR-18a antagomir sensitizes ESCC cells to cisplatin.

Laser beam welding of new ultra-high strength and supra-ductile steels

OpenAIRE

Dahmen, M.

2015-01-01

Ultra-high strength and supra-ductile are entering fields of new applications. Those materials are excellent candidates for modern light-weight construction and functional integration. As ultra-high strength steels the stainless martensitic grade 1.4034 and the bainitic steel UNS 53835 are investigated. For the supra-ductile steels stand two high austenitic steels with 18 and 28 % manganese. As there are no processing windows an approach from the metallurgical base on is required. Adjusting t...

Hypereutectoid steel in early medieval sword production in Europe

Czech Academy of Sciences Publication Activity Database

Kucypera, P.; Hošek, Jiří

2014-01-01

Roč. 27, [1] (2014), s. 31-39 ISSN 0860-0007 R&D Projects: GA ČR GAP405/12/2289 Institutional support: RVO:67985912 Keywords : swords * Early Middle Ages * hypereutectoid steel Subject RIV: AC - Archeology, Anthropology, Ethnology

Joint formation of dissimilar steels in pressure welding with superposition of ultrasonic oscillations

Energy Technology Data Exchange (ETDEWEB)

Surovtsev, A P; Golovanenko, S A; Sukhanov, V E; Kazantsev, V F

1983-12-01

Investigation results of kinetics and quality of carbon steel joints with the steel 12Kh18N10T, obtained by pressure welding with superposition of ultrasonic oscillations with the frequency 16.5-18.0 kHz are given. The effect of ultrasonic oscillations on the process of physical contact development of the surfaces welded, formation of microstructure and impact viscosity of the compound, is shown.

The application of DCPD method to evaluating dynamic J-R fracture resistance characteristics

International Nuclear Information System (INIS)

Yoon, Ji Hyun; Hong, Jun Hwa; Lee, Bong Sang; Chi, Se Whan; Kim, Joo Hag; Oh, Yong Jun; Kwun, Sun Chil; Oh, Jong Myung

1999-06-01

The reliable DCPD (Direct Current Potential Drop) test and data acquisition system were developed on the basis of analysis of various technical problems to accompanied with the application of DCPD method to J-R fracture resistance test. The test system contains electric insulation rod and high performance data acquisition system. The test and analysis method was applied to J-R fracture resistance test for SA516-Gr.70 steel for nuclear primary coolant system elbow. The reliabilities of test and analysis method were confirmed through the load-ratio method in case of dynamic loading test, and through the standard unloading compliance test in case of static loading test. (author). 17 refs., 1 tab., 18 figs

The application of DCPD method to evaluating dynamic J-R fracture resistance characteristics

Energy Technology Data Exchange (ETDEWEB)

Yoon, Ji Hyun; Hong, Jun Hwa; Lee, Bong Sang; Chi, Se Whan; Kim, Joo Hag; Oh, Yong Jun; Kwun, Sun Chil; Oh, Jong Myung

1999-06-01

The reliable DCPD (Direct Current Potential Drop) test and data acquisition system were developed on the basis of analysis of various technical problems to accompanied with the application of DCPD method to J-R fracture resistance test. The test system contains electric insulation rod and high performance data acquisition system. The test and analysis method was applied to J-R fracture resistance test for SA516-Gr.70 steel for nuclear primary coolant system elbow. The reliabilities of test and analysis method were confirmed through the load-ratio method in case of dynamic loading test,and through the standard unloading compliance test in case of static loading test. (author). 17 refs., 1 tab., 18 figs.

Mechanistic studies of carbon steel corrosion inhibition by cashew ...

African Journals Online (AJOL)

The phenoxide, R-Ar-O- ions from the CNSL inhibitor were found to be responsible for the reduction of the corrosion rate of the carbon steel. Also, it was observed that the surface charge of the carbon steel electrodes was positive with respect to the solutions containing CNSL inhibitor. It is likely that the mechanism of the ...

Mechanical Properties, Short Time Creep, and Fatigue of an Austenitic Steel

Directory of Open Access Journals (Sweden)

Josip Brnic

2016-04-01

Full Text Available The correct choice of a material in the process of structural design is the most important task. This study deals with determining and analyzing the mechanical properties of the material, and the material resistance to short-time creep and fatigue. The material under consideration in this investigation is austenitic stainless steel X6CrNiTi18-10. The results presenting ultimate tensile strength and 0.2 offset yield strength at room and elevated temperatures are displayed in the form of engineering stress-strain diagrams. Besides, the creep behavior of the steel is presented in the form of creep curves. The material is consequently considered to be creep resistant at temperatures of 400 °C and 500 °C when subjected to a stress which is less than 0.9 of the yield strength at the mentioned temperatures. Even when the applied stress at a temperature of 600 °C is less than 0.5 of the yield strength, the steel may be considered as resistant to creep. Cyclic tensile fatigue tests were carried out at stress ratio R = 0.25 using a servo-pulser machine and the results were recorded. The analysis shows that the stress level of 434.33 MPa can be adopted as a fatigue limit. The impact energy was also determined and the fracture toughness assessed.

Mechanical Properties, Short Time Creep, and Fatigue of an Austenitic Steel.

Science.gov (United States)

Brnic, Josip; Turkalj, Goran; Canadija, Marko; Lanc, Domagoj; Krscanski, Sanjin; Brcic, Marino; Li, Qiang; Niu, Jitai

2016-04-20

The correct choice of a material in the process of structural design is the most important task. This study deals with determining and analyzing the mechanical properties of the material, and the material resistance to short-time creep and fatigue. The material under consideration in this investigation is austenitic stainless steel X6CrNiTi18-10. The results presenting ultimate tensile strength and 0.2 offset yield strength at room and elevated temperatures are displayed in the form of engineering stress-strain diagrams. Besides, the creep behavior of the steel is presented in the form of creep curves. The material is consequently considered to be creep resistant at temperatures of 400 °C and 500 °C when subjected to a stress which is less than 0.9 of the yield strength at the mentioned temperatures. Even when the applied stress at a temperature of 600 °C is less than 0.5 of the yield strength, the steel may be considered as resistant to creep. Cyclic tensile fatigue tests were carried out at stress ratio R = 0.25 using a servo-pulser machine and the results were recorded. The analysis shows that the stress level of 434.33 MPa can be adopted as a fatigue limit. The impact energy was also determined and the fracture toughness assessed.

Corrosion properties of plasma deposited high-alloy steel

Czech Academy of Sciences Publication Activity Database

Voleník, Karel; Pražák, M.; Kalabisová, E.; Kreislová, K.; Neufuss, Karel

2002-01-01

Roč. 47, - (2002), s. 243-254 ISSN 0001-7043 R&D Projects: GA ČR GA106/99/0298 Institutional research plan: CEZ:AV0Z2043910 Keywords : plasma deposits, high-alloy steel, polarization curves, corrosion test Subject RIV: BL - Plasma and Gas Discharge Physics

Phenomenological study of the microdeformations produced at the beginning of primary creep under low stresses in an austenitic stainless steel of Z3CND 18-13 type

International Nuclear Information System (INIS)

Calvet, J.-N.; Le Bret, P.; Roulliay, R.

1975-01-01

A creep machine was modified enabling tests to be carried out at 550 deg C under 8hbar. The modulus of elasticity, yield strength, plastic deformation on loading, creep deformation and total plastic deformation were determined in an austenitic stainless steel of Z3CND 18-13 type. A relationship was established between the plastic deformation on loading and the creep deformation [fr

Effect of Isothermal Bainitic Quenching on Rail Steel Impact Strength and Wear Resistance

Science.gov (United States)

Çakir, Fatih Hayati; Çelik, Osman Nuri

2017-09-01

The effect of heat treatment regimes on hardness, impact strength, and wear resistance of rail steel for high-speed tracks (rail quality category R350HT) is studied. Analysis of steel properties with a different structure is compared: pearlitic, and upper and lower bainite. It is shown that the steel with bainitic structure has the best impact strength, but wear resistance is better for steel with a lower bainite structure.

miR-18b overexpression identifies mantle cell lymphoma patients with poor outcome and improves the MIPI-B prognosticator

DEFF Research Database (Denmark)

Husby, Simon; Ralfkiær, Ulrik Methner; Garde, Christian

2015-01-01

Recent studies show that mantle cell lymphoma (MCL) express aberrant microRNA (miRNA) profiles; however, the clinical effect of miRNA expression has not previously been examined and validated in large prospective homogenously treated cohorts. We performed genome-wide miRNA microarray profiling...... by decelerating cell proliferation. We conclude that overexpression of miR-18b identifies patients with poor prognosis in 2 large prospective MCL cohorts and adds prognostic information to the MIPI-B. MiR-18b may reduce the proliferation rate of MCL cells as a mechanism of chemoresistance....

Possible influences on textures in unalloyed steels and their effects on steel properties

International Nuclear Information System (INIS)

Grossterlinden, R.; Imlau, K.P.; Kawalla, R.; Lotter, U.; Reip, C.-P.

1996-01-01

Textures in steels play an essential role for applications where anisotropic properties are favourable. For the example of deep-drawing steel sheet the correlation between parameters characterising the behaviour in the deep-drawing process, as Lankford r-value and planar anisotropy Δr, and the crystallographic texture is considered. Furthermore, the development of texture in the course of manufacturing cold strip is followed for unalloyed and microalloyed deep-drawing grades. For representation of typical features of textures the method of orientation distribution functions (ODF) together with the description of texture by characteristic fibres is used. In detail, the parameters influencing textures, such as chemical composition, finishing temperature in the hot-rolling mill (in relation to the austenite or ferrite region), transformation behaviour, cold-rolling reduction and the course of temperature during recrystallizing annealing, are discussed. From the given survey it may be concluded, that in the manufacturing process there are many possibilities to control the texture of the finished product. Finally, it is shown that the impact of textures on the r-value can be calculated with high precision. On the other hand, the formation of texture itself, particularly during hot-rolling, transformation and recrystallization after cold-rolling, at present can be calculated and modelled only in simple cases. (orig.)

Mechanical Behavior of Additive Manufactured Layered Materials, Part 2: Stainless Steels

Science.gov (United States)

2015-04-30

materials. Elsevier, Oxford; 2007: 416 -420. [19] Deng, D., Chen, R., Sun, Q. and Li, X. Microstructural study of 17-4PH stainless steel after plasma...1 Mechanical Behavior of Additive Manufactured Layered Materials, Part 2: Stainless Steels * Todd M. Mower † and Michael J. Long M.I.T. Lincoln... stainless steel alloys produced with Direct Metal Laser Sintering (DMLS) was measured and is compared to that of similar conventional materials

A Simple Method to Decode the Complete 18-5.8-28S rRNA Repeated Units of Green Algae by Genome Skimming.

Science.gov (United States)

Lin, Geng-Ming; Lai, Yu-Heng; Audira, Gilbert; Hsiao, Chung-Der

2017-11-06

Green algae, Chlorella ellipsoidea , Haematococcus pluvialis and Aegagropila linnaei (Phylum Chlorophyta) were simultaneously decoded by a genomic skimming approach within 18-5.8-28S rRNA region. Whole genomic DNAs were isolated from green algae and directly subjected to low coverage genome skimming sequencing. After de novo assembly and mapping, the size of complete 18-5.8-28S rRNA repeated units for three green algae were ranged from 5785 to 6028 bp, which showed high nucleotide diversity (π is around 0.5-0.6) within ITS1 and ITS2 (Internal Transcribed Spacer) regions. Previously, the evolutional diversity of algae has been difficult to decode due to the inability design universal primers that amplify specific marker genes across diverse algal species. In this study, our method provided a rapid and universal approach to decode the 18-5.8-28S rRNA repeat unit in three green algal species. In addition, the completely sequenced 18-5.8-28S rRNA repeated units provided a solid nuclear marker for phylogenetic and evolutionary analysis for green algae for the first time.

Corrosion-resistant coating technique for oxide-dispersion-strengthened ferritic/martensitic steel

International Nuclear Information System (INIS)

Sakasegawa, Hideo; Tanigawa, Hiroyasu; Ando, Masami

2014-01-01

Oxide-dispersion-strengthened (ODS) steels are attractive materials for application as fuel cladding in fast reactors and first-wall material of fusion blanket. Recent studies have focused more on high-chromium ferritic (12-18 wt% Cr) ODS steels with attractive corrosion resistance properties. However, they have poor material workability, require complicated heat treatments for recrystallization, and possess anisotropic microstructures and mechanical properties. On the other hand, low-chromium ferritic/martensitic (8-9 wt% Cr) ODS steels have no such limitations; nonetheless, they have poor corrosion resistance properties. In our work, we developed a corrosion-resistant coating technique for a low-chromium ferritic/martensitic ODS steel. The ODS steel was coated with the 304 or 430 stainless steel, which has better corrosion resistances than the low-chromium ferritic/martensitic ODS steels. The 304 or 430 stainless steel was coated by changing the canning material from mild steel to stainless steel in the conventional material processing procedure for ODS steels. Microstructural observations and micro-hardness tests proved that the stainless steels were successfully coated without causing a deterioration in the mechanical property of the low-chromium ferritic/martensitic ODS steel. (author)

Magnetoacoustic measurements on steel samples at low magnetizing frequencies

Czech Academy of Sciences Publication Activity Database

Perevertov, Oleksiy; Stupakov, Alexandr

2015-01-01

Roč. 66, č. 7 (2015), s. 58-61 ISSN 1335-3632 R&D Projects: GA ČR GA13-18993S; GA ČR GB14-36566G Institutional support: RVO:68378271 Keywords : magneto-acoustic emission * surface magnetic field * steel * magnetic hysteresis Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 0.407, year: 2015

Long-term Stability of 9- to 12 % Cr Steels

DEFF Research Database (Denmark)

Hald, John

2004-01-01

In the recent 25 years creep rupture strength of 9- to 12 %Cr steels for steam pipes and turbines has been doubled by development of new alloys. This development has formed a basis for improved efficiency of fossil fired steam power plants by introduction of advanced steam temperatures...... and pressures. Newly developed steam pipe steels are based on modifications of well-established steels like the X 20CrMoV12 1. Balanced addition of V, Nb and N to a 9Cr 1 Mo steel led to the Modified 9 Cr steel P 91. Addition of 1% W to a 9Cr 1 MoVNbN base composition led to steel E 911 and partial replacement...... of Mo with 1.8 % W combined with a slight amount of Boron led to steel P 92. The creep rupture strength of these new alloys are now secured with long-term tests up to 100,000 hours, which demonstrate improvements of 50% (P 91), 75 % (E 911) and 100 % (P 92) in strength compared to X 20CrMoV12 1....

Expression of IL-18, IL-18 Binding Protein, and IL-18 Receptor by Normal and Cancerous Human Ovarian Tissues: Possible Implication of IL-18 in the Pathogenesis of Ovarian Carcinoma

Directory of Open Access Journals (Sweden)

Liat Medina

2014-01-01

Full Text Available Proinflammatory cytokine IL-18 has been shown to be elevated in the sera of ovarian carcinoma patients. The aim of the study was to examine the levels and cellular origin of IL-18, IL-18 binding protein, and IL-18 receptor in normal and cancerous ovarian tissues. Ovarian tissue samples were examined by immunohistochemical staining for IL-18, IL-18BP, and IL-18R and mRNA of these cytokines was analyzed with semiquantitative PT-PCR. IL-18 levels were significantly higher in cancerous ovarian tissues (P=0.0007, IL-18BP levels were significantly higher in normal ovarian tissues (P=0.04, and the ratio of IL-18/IL-18BP was significantly higher in cancerous ovarian tissues (P=0.036. Cancerous ovarian tissues expressed significantly higher IL-18 mRNA levels (P=0.025, while there was no difference in the expression of IL-18BP mRNA and IL-18R mRNA between cancerous and normal ovarian tissues. IL-18 and IL-18BP were expressed dominantly in the epithelial cells of both cancerous and normal ovarian tissues, while IL-18R was expressed dominantly in the epithelial cells of cancerous ovarian tissues but expressed similarly in the epithelial and stromal cells of normal cancerous tissues. This study indicates a possible role of IL-18, IL-18BP, and IL-18R in the pathogenesis of epithelial ovarian carcinoma.

18FDG-PET predicts pharmacodynamic response to OSI-906, a dual IGF-1R/IR inhibitor, in preclinical mouse models of lung cancer.

Science.gov (United States)

McKinley, Eliot T; Bugaj, Joseph E; Zhao, Ping; Guleryuz, Saffet; Mantis, Christine; Gokhale, Prafulla C; Wild, Robert; Manning, H Charles

2011-05-15

To evaluate 2-deoxy-2-[(18)F]fluoro-d-glucose positron emission tomography imaging ((18)FDG-PET) as a predictive, noninvasive, pharmacodynamic (PD) biomarker of response following administration of a small-molecule insulin-like growth factor-1 receptor and insulin receptor (IGF-1R/IR) inhibitor, OSI-906. In vitro uptake studies of (3)H-2-deoxy glucose following OSI-906 exposure were conducted evaluating correlation of dose with inhibition of IGF-1R/IR as well as markers of downstream pathways and glucose metabolism. Similarly, in vivo PD effects were evaluated in human tumor cell line xenografts propagated in athymic nude mice by (18)FDG-PET at 2, 4, and 24 hours following a single treatment of OSI-906 for the correlation of inhibition of receptor targets and downstream markers. Uptake of (3)H-2-deoxy glucose and (18)FDG was significantly diminished following OSI-906 exposure in sensitive tumor cells and subcutaneous xenografts (NCI-H292) but not in an insensitive model lacking IGF-1R expression (NCI-H441). Diminished PD (18)FDG-PET, collected immediately following the initial treatment agreed with inhibition of pIGF-1R/pIR, reduced PI3K (phosphoinositide 3-kinase) and MAPK (mitogen activated protein kinase) pathway activity, and predicted tumor growth arrest as measured by high-resolution ultrasound imaging. (18)FDG-PET seems to serve as a rapid, noninvasive PD marker of IGF-1R/IR inhibition following a single dose of OSI-906 and should be explored clinically as a predictive clinical biomarker in patients undergoing IGF-1R/IR-directed cancer therapy. ©2011 AACR.

Complete sequence analysis of 18S rDNA based on genomic DNA extraction from individual Demodex mites (Acari: Demodicidae).

Science.gov (United States)

Zhao, Ya-E; Xu, Ji-Ru; Hu, Li; Wu, Li-Ping; Wang, Zheng-Hang

2012-05-01

The study for the first time attempted to accomplish 18S ribosomal DNA (rDNA) complete sequence amplification and analysis for three Demodex species (Demodex folliculorum, Demodex brevis and Demodex canis) based on gDNA extraction from individual mites. The mites were treated by DNA Release Additive and Hot Start II DNA Polymerase so as to promote mite disruption and increase PCR specificity. Determination of D. folliculorum gDNA showed that the gDNA yield reached the highest at 1 mite, tending to descend with the increase of mite number. The individual mite gDNA was successfully used for 18S rDNA fragment (about 900 bp) amplification examination. The alignments of 18S rDNA complete sequences of individual mite samples and those of pooled mite samples ( ≥ 1000mites/sample) showed over 97% identities for each species, indicating that the gDNA extracted from a single individual mite was as satisfactory as that from pooled mites for PCR amplification. Further pairwise sequence analyses showed that average divergence, genetic distance, transition/transversion or phylogenetic tree could not effectively identify the three Demodex species, largely due to the differentiation in the D. canis isolates. It can be concluded that the individual Demodex mite gDNA can satisfy the molecular study of Demodex. 18S rDNA complete sequence is suitable for interfamily identification in Cheyletoidea, but whether it is suitable for intrafamily identification cannot be confirmed until the ascertainment of the types of Demodex mites parasitizing in dogs. Copyright © 2012 Elsevier Inc. All rights reserved.

Estimation of fracture toughness of cast stainless steels during thermal aging in LWR systems-revision 1

International Nuclear Information System (INIS)

Chopra, O.K.

1994-08-01

This report presents a revision of the procedure and correlations presented earlier in NUREG/CR-4513, ANL-90/42 (June 1991) for predicting the change in mechanical properties of cast stainless steel components due to thermal aging during service in light water reactors at 280-330 degrees C (535-625 degrees F). The correlations presented in this report are based on an expanded data base and have been optimized with mechanical-property data on cast stainless steels aged up to ∼58,000 h at 290-350 degrees C (554-633 degrees F). The fracture toughness J-R curve, tensile stress, and Charpy-impact energy of aged cast stainless steels are estimated from known material information. Mechanical properties of a specific cast stainless steel are estimated from the extent and kinetics of thermal embrittlement. Embrittlement of cast stainless steels is characterized in terms of room-temperature Charpy-impact energy. Charpy-impact energy as a function of time and temperature of reactor service is estimated from the kinetics of thermal embrittlement, which are also determined from the chemical composition. The initial impact energy of the unaged steel is required for these estimations. Initial tensile flow stress is needed for estimating the flow stress of the aged material. The fracture toughness J-R curve for the material is then obtained by correlating room-temperature Charpy-impact energy with fracture toughness parameters. The values of J IC are determined from the estimated J-R curve and flow stress. A common open-quotes predicted lower-boundclose quotes J-R curve for cast stainless steels of unknown chemical composition is also defined for a given grade of steel, range of ferrite content, and temperature. Examples of estimating mechanical properties of cast stainless steel components during reactor service are presented

Reactor Structural Materials: Reactor Pressure Vessel Steels

International Nuclear Information System (INIS)

Chaouadi, R.

2000-01-01

The objectives of SCK-CEN's R and D programme on Rector Pressure Vessel (RPV) Steels are:(1) to complete the fracture toughness data bank of various reactor pressure vessel steels by using precracked Charpy specimens that were tested statically as well as dynamically; (2) to implement the enhanced surveillance approach in a user-friendly software; (3) to improve the existing reconstitution technology by reducing the input energy (short cycle welding) and modifying the stud geometry. Progress and achievements in 1999 are reported

76 FR 59658 - High Pressure Steel Cylinders From the People's Republic of China: Postponement of Preliminary...

Science.gov (United States)

2011-09-27

... DEPARTMENT OF COMMERCE International Trade Administration [A-570-977] High Pressure Steel... (``Department'') initiated an antidumping duty investigation on high pressure steel cylinders from the People's... for this investigation is currently due no later than October 18, 2011. \\1\\ See High Pressure Steel...

Fatigue characteristics of dual-phase steel sheets

Energy Technology Data Exchange (ETDEWEB)

Onn, Irwan Herman; Ahmad, Norhayati; Tamin, Mohd Nasir [Universiti Teknologi Malaysia, Skudai (Malaysia)

2015-01-15

Fatigue characteristics of dual-phase steel sheets, commonly used in automobile body construction were established. For this purpose, a series of fatigue tests, each at constant stress amplitude were conducted on 1.2 mm-thick, dual-phase DP600 steel sheet specimens with two different load ratios of minimum-to-maximum stress, R = 0.1 and -1. The resulting fatigue behavior is expressed in terms of fatigue strength-life (S-N) curves. Fatigue behavior of the steel sheets in the high-cycle fatigue region can be represented by Basquin's equation with coefficient and exponent value of 921.2 and 0.093, respectively. An endurance limit of 255 MPa is observed. In addition, fatigue strengths of the dual-phase steel sheets display lower magnitude than their bulk counterparts. Effect of mean stress on fatigue behavior of the steel sheets is well predicted by Walker's model. Exponential calibration factor is introduced to the models by SWT, Goodman and Morrow with comparable prediction to the Walker's model.

Steel corrosion in tributyl phosphate in the presence of water and ethyl mercaptan

International Nuclear Information System (INIS)

Pischik, L.M.; Tsinman, A.I.

1979-01-01

Studied is the corrosion of steels St3, 15Kh5M, 08Kh13, 10Kh14G14N4T, 08Kh18G8N2T, 10Kh17N13M2T in TBP, in mixtures of TBP with ethyl mercaptan (EM) and two-phase systems TBP-water and TBP-water-EM at 50-150 deg. In pure TBP St3 corrosion rate is low even at 150 deg. In the presence of water St 3 strongly corrodes at above 50 deg temperature in organic and water layers and also in gas phase. The steel-08Kh18G8N2T at 90 deg in acid TBP is passive and its corrosion rate is lower than 0.01 mm/year. In identical conditions the resistance of stainless steels increases together with chromium content but in TBP with acid number 100 and above at 150 deg all tested steels including steel-10Kh17N13M2T are slightly resistant. Thus, even in absence of corrosion active additions of EM the mixture of TBP-water at higher temperature is agressive in relation not only to carbon steel but also to stainless steels

Comparative physical mapping of 18S rDNA in the karyotypes of six leafcutter ant species of the genera Atta and Acromyrmex (Formicidae: Myrmicinae).

Science.gov (United States)

Teixeira, Gisele Amaro; Barros, Luísa Antônia Campos; de Aguiar, Hilton Jeferson Alves Cardoso; das Graças Pompolo, Silvia

2017-10-01

Leafcutter ants of the Atta and Acromyrmex genera are important plagues in different cultures. Cytogenetic data on chromosome number, morphology, and chromosomal banding pattern are only available for 17 species of leafcutter ants. Molecular cytogenetic data for the detection of ribosomal genes by the FISH technique are scarce, and only 15 Neotropical ant species have been studied. This study aimed to physically map the 18S ribosomal RNA genes (rDNA) of six leafcutter ants belonging to the genera Atta and Acromyrmex using FISH. The results were compared with data on the fluorochrome CMA 3 currently available for these species. All analyzed species presented the 18S rDNA on one pair of chromosomes. In Acromyrmex subterraneus molestans and Ac. aspersus, FISH signals were observed in the terminal region of the short arm of the largest subtelocentric pair, while in Atta bisphaerica, A. laevigata, and A. sexdens, FISH signals were observed in the interstitial region of the long arm of the fourth metacentric pair. In Acromyrmex striatus, 18S rDNA was located in the interstitial region of the second metacentric pair. The karyotypic formula for Ac. aspersus was 2n = 38 (8m + 10sm + 16st + 4a), representing the first report in this species. The observed 18S rDNA regions in A. laevigata, A. sexdens, A. bisphaerica, Ac. aspersus, and Ac. subterraneus molestans corresponded to the CMA 3 + bands, while in Ac. striatus, several GC-rich bands and one pair of 18S rDNA bands were observed. No differential bands were visible using the DAPI fluorochrome. Karyotype uniformity with previously studied Atta spp. was also observed at the level of molecular cytogenetics using 18S rDNA FISH. A difference in the size of the chromosomal pair carrying the 18S rDNA gene was observed in Ac. striatus (2n = 22) and Atta spp. (2n = 22) highlighting the dissimilarity between these species. The results from the present study contribute to the description of 18S rDNA clusters

The influence of cold work on the oxidation behaviour of stainless steel

International Nuclear Information System (INIS)

Langevoort, J.C.

1985-01-01

In this thesis the study of the interaction of oxygen gas with stainless steel surfaces is described. Thermogravimetry, microscopy and ellipsometry have been used to follow the oxidation in situ, while EDX, AES and XPS have been used to determine the oxide compositions. The aim of this thesis is to reveal the influence on the oxidation behaviour of stainless steel of i) cold work (rolling, drawing, milling, polishing and Ar ion bombardment) ii) the initially formed oxide and iii) the experimental conditions. Two types of stainless steels have been used (AISI 304 (a 18/8 Cr/Ni steel) and Incoloy 800 H (a 20/30 Cr/Ni steel)). (Auth.)

Structural transformations in austenitic stainless steel induced by deuterium implantation: irradiation at 100 K.

Science.gov (United States)

Morozov, Oleksandr; Zhurba, Volodymyr; Neklyudov, Ivan; Mats, Oleksandr; Rud, Aleksandr; Chernyak, Nikolay; Progolaieva, Viktoria

2015-01-01

Deuterium thermal desorption spectra were investigated on the samples of austenitic stainless steel 18Cr10NiTi preimplanted at 100 K with deuterium ions in the dose range from 3 × 10(15) to 5 × 10(18) D/cm(2). The kinetics of structural transformation development in the implantation steel layer was traced from deuterium thermodesorption spectra as a function of implanted deuterium concentration. At saturation of austenitic stainless steel 18Cr10NiTi with deuterium by means of ion implantation, structural-phase changes take place, depending on the dose of implanted deuterium. The maximum attainable concentration of deuterium in steel is C = 1 (at.D/at.met. = 1/1). The increase in the implanted dose of deuterium is accompanied by the increase in the retained deuterium content, and as soon as the deuterium concentration attains C ≈ 0.5 the process of shear martensitic structural transformation in steel takes place. It includes the formation of bands, body-centered cubic (bcc) crystal structure, and the ferromagnetic phase. Upon reaching the deuterium concentration C > 0.5, the presence of these molecules causes shear martensitic structural transformations in the steel, which include the formation of characteristic bands, bcc crystal structure, and the ferromagnetic phase. At C ≥ 0.5, two hydride phases are formed in the steel, the decay temperatures of which are 240 and 275 K. The hydride phases are formed in the bcc structure resulting from the martensitic structural transformation in steel.

An internal friction peak caused by hydrogen in maraging steel

International Nuclear Information System (INIS)

Usui, Makoto; Asano, Shigeru

1996-01-01

Internal friction in hydrogen-charged iron and steel has so far been studied by a large number of investigators. For pure iron, a well-defined peak of internal friction has been observed under the cold-worked and hydrogen-charged conditions. This is called the hydrogen cold-work peak, or the Snoek-Koester relaxation, which originates from the hydrogen-dislocation interaction. In the present study, a high-strength maraging steel (Fe-18Ni-9Co-5Mo) was chosen as another high-alloy steel which is known to be very susceptible to hydrogen embrittlement. The purpose of this paper is to show a new internal friction peak caused by hydrogen in the maraging steel and to compare it with those found in stainless steels which have so far been studied as typical engineering high-alloy materials

Estimates of the potential for energy conservation in the Chinese steel industry

International Nuclear Information System (INIS)

Lin Boqiang; Wu Ya; Zhang Li

2011-01-01

The study evaluates the energy saving potential of the Chinese steel industry by studying its potential future energy efficiency gap. In order to predict the future energy efficiency gap, a multivariate regression model combined with risk analysis is developed to estimate future energy intensity of China's steel industry. It is found that R and D intensity, energy saving investment, labor productivity and industry concentration are all important variables that affect energy intensity. We assess the possible measures as to how China's steel industry can narrow the energy efficiency gap with Japan by means of scenario analysis. Using Japan's current energy efficiency level as baseline, the energy saving potential of China's steel industry is more than 200 million ton coal equivalent in 2008, and it would fall to zero in 2020. However, if greater efforts were made to conserve energy, it would be possible to narrow down the energy efficiency gap between China and Japan by around 2015. Finally, using the results of the scenario analysis, future policy priorities for energy conservation in China's steel industry are assessed in this paper. - Highlights: → The energy saving potential of the Chinese steel industry is evaluated. → A multivariate regression model combined with risk analysis is developed. → R and D, energy saving investment, labor, and structure affect energy intensity.→ The energy saving potential of China's steel industry would fall to zero in 2020.→ Future policy for energy conservation in China's steel industry are assessed.

The compatibility of various austenitic steels with molten sodium (1963)

International Nuclear Information System (INIS)

Champeix, L.; Sannier, J.; Darras, R.; Graff, W.; Juste, P.

1963-01-01

Various techniques for studying corrosion by molten sodium have been developed and applied to the case of 18/10 austenitic steels. The results obtained are discussed as a function of various parameters: type of steel, temperature, oxygen content of the sodium, surface treatment, welds, mechanical strain. In general, these steels have an excellent resistance to sodium when the oxygen content is limited by a simple purification system of the 'cold trap' type, and when an attempt is made to avoid cavitation phenomena which are particularly dangerous, as is shown by the example given. (authors) [fr

Radiation induced microstructural evolution in ferritic/martensitic steels

International Nuclear Information System (INIS)

Kohno, Y.; Kohyama, A.; Asakura, K.; Gelles, D.S.

1993-01-01

R and D of ferritic/martensitic steels as structural materials for fusion reactor is one of the most important issues of fusion technology. The efforts to characterize microstructural evolution under irradiation in the conventional Fe-Cr-Mo steels as well as newly developed Fe-Cr-Mn or Fe-Cr-W low activation ferritic/ martensitic steels have been continued. This paper provides some of the recent results of heavy irradiation effects on the microstructural evolution of ferritic/martensitic steels neutron irradiated in the FFTF/MOTA (Fast Flux Test Facility/Materials Open Test Assembly). Materials examined are Fe-10Cr-2Mo dual phase steel (JFMS: Japanese Ferritic/Martensitic Steel), Fe-12Cr-XMn-1Mo manganese stabilized martensitic steels and Fe-8Cr-2W Tungsten stabilized low activation martensitic steel (F82H). JFMS showed excellent void swelling resistance similar to 12Cr martensitic steel such as HT-9, while the manganese stabilized steels and F82H showed less void swelling resistance with small amount of void swelling at 640-700 K (F82H: 0.14% at 678 K). As for irradiation response of precipitate behavior, significant formation of intermetallic χ phase was observed in the manganese stabilized steels along grain boundaries which is though to cause mechanical property degradation. On the other hand, precipitates identified were the same type as those in unirradiated condition in F82H with no recognition of irradiation induced precipitates, which suggested satisfactory mechanical properties of F82H after the irradiation. (author)

Corrosion of chromium, nickel, titanium and steels in solutions of sodium and ammonium thiosulfates

International Nuclear Information System (INIS)

Grebenshchikova, S.V.; Kochergin, V.P.; Doronina, I.V.

1983-01-01

Results of gravimetric determinatiion of average rate of chromium, nickel, titatnium and steels 12Kh18N10T and VSt.3 corrosion rate in solutions 50 mass.% (NH 4 ) 2 S 2 O 3 and Na 2 S 2 O 3 in the air and nitrogen atmosphere at 333 K have been generalized. Anodic polarization curves are recorded and stationary potentials of metals and steels under the conditions are measured. It is shown that in (NH 4 ) 2 S 2 O 3 solution the rate of metal and steels corrosion is higher than in Na 2 S 2 O 3 solution indepenent of the nature of gaseous medium contacting with solution. In the series Ni → VSt.3 → 12Kh18N10T → VT1 → chromium in (NH 4 ) 2 S 2 O 3 and Na 2 S 2 O 3 solutions at 333 K corrosion resistance increases. Chromium, titanium and chromium-nickel steel 12Kh18N10T possess a high corrosion resistance

Study of the Weldability of Austenitic PH Steel for Power Plants

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Ziewiec A.

2016-06-01

Full Text Available The article presents the results of Transvarestraint test of a modern precipitation hardened steel X10CrNiCuNb18-9-3 with copper. For comparison, the results of tests of conventional steel without the addition of copper X5CrNi18-10 are presented. The total length of all cracks and the maximum length of cracks were measured. The study of microstructure (LM, SEM showed that the austenitic stainless steel X10CrNiCuNb18-9-3 is very prone to hot cracking. After performing the Transvarestraint tests three types of cracks were observed: solidification cracks occurring during crystallization, liquation cracks due to segregation in the heat affected zone (HAZ and surface cracks. Niobium carbonitrides dispersed in the bands of segregation are the reason of high susceptibility to liquation cracking. Segregation of copper occurring during solidification causes of surface cracking. A combined effect of copper and stresses contributes to formation of hot microcracks. These microcracks propagate to a depth of 20-30 μm.

Laser beam welding of new ultra-high strength and supra-ductile steels

Science.gov (United States)

Dahmen, Martin

2015-03-01

Ultra-high strength and supra-ductile are entering fields of new applications. Those materials are excellent candidates for modern light-weight construction and functional integration. As ultra-high strength steels the stainless martensitic grade 1.4034 and the bainitic steel UNS 53835 are investigated. For the supra-ductile steels stand two high austenitic steels with 18 and 28 % manganese. As there are no processing windows an approach from the metallurgical base on is required. Adjusting the weld microstructure the Q+P and the QT steels require weld heat treatment. The HSD steel is weldable without. Due to their applications the ultra-high strength steels are welded in as-rolled and strengthened condition. Also the reaction of the weld on hot stamping is reflected for the martensitic grades. The supra-ductile steels are welded as solution annealed and work hardened by 50%. The results show the general suitability for laser beam welding.

Changes in structure and phase composition of chromium diffusion layer on stainless steels after long annealing

International Nuclear Information System (INIS)

Knyazev, E.V.; Voshedchenko, B.M.; Voskresenskij, Yu.A.

1985-01-01

A study was made on the effect of elevated temperatures UU and long holdings at heat on structure, phase composition and properties of chromium diffusion layer on austenitic chromium-nickel stainless steels 10Kh18N10TVD, 10Kh15N30M4B, 10Kh11N23T3MR, 10Kh21N28V6M3. The following mechanism of processes taking place in diffusion chromium layer is presented. The steady drop of chromium concentrations is observed after diffusion saturation. Chromium redistribution related with system transformation to more equilibrium state and simultaneous decarburization of steel surfaces takes place in diffusion layers of 10Kh15N30M4B and 10Kh21N28V6M3 steels after annealing at different temperatures and holdings at heat. Decarburization of steel surface layers is practically excluded in diffusion layers of 10Kh18N10T-VD and 10Kh11N23T3MR steels. Diffusion chromium-saturated layer stays effective only on 10Kh18N10T-VD and 10Kh11N23T3MR steels on heating up to 1000 deq C with holding up to 250 h

Low cycle fatigue properties of CLAM steel at 823 K

Energy Technology Data Exchange (ETDEWEB)

Hu, Xue [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); University of Chinese Academy of Sciences, 19 Yuquan Road, Beijing 100049 (China); Huang, Lixin [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Yan, Wei; Wang, Wei [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Sha, Wei [School of Planning, Architecture and Civil Engineering, Queen' s University Belfast, Belfast BT9 5AG (United Kingdom); Shan, Yiyin, E-mail: yyshan@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China); Yang, Ke, E-mail: kyang@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, 72 Wenhua Road, Shenyang 110016 (China)

2014-09-08

China Low Activation Martensitic (CLAM) steel is considered to be the main candidate material for the first wall components of future fusion reactors in China. In this paper, the low cycle fatigue (LCF) behavior of CLAM steel is studied under fully reversed tension–compression loading at 823 K in air. Total strain amplitude was controlled from 0.14% to 1.8% with a constant strain rate of 2.4×10{sup −3} s{sup −1}. The corresponding plastic strain amplitude ranged from 0.023% to 1.613%. The CLAM steel displayed continuous softening to failure at 823 K. The relationship between strain, stress and fatigue life was obtained using the parameters obtained from fatigue tests. The LCF properties of CLAM steel at 823 K followed Coffin–Manson relationship. Furthermore, irregular serration was observed on the stress–strain hysteresis loops of CLAM steel tested with the total strain amplitude of 0.45–1.8%, which was attributed to the dynamic strain aging (DSA) effect. During continuous cyclic deformation, the microstructure and precipitate distribution of CLAM steel changed gradually. Many tempered martensitic laths were decomposed into subgrains, and the size and number of M{sub 23}C{sub 6} carbide and MX carbonitride precipitates decreased with the increase of total strain amplitude. The response cyclic stress promoted the recovery of martensitic lath, while the thermal activation mainly played an important role on the growth of precipitates in CLAM steel at 823 K. In order to have a better understanding of high-temperature LCF behavior, the potential mechanisms controlling stress–strain response, DSA phenomenon and microstructure changes have also been evaluated.

Synthesis of stereo (R and S) and geometric (E and Z) [F-18]fluoro-β-fluoromethylene-M-tyrosine derivatives: specific PET probes for central dopamine systems

International Nuclear Information System (INIS)

Lacan, G.; Barrio, J.R.; Satyamurthy, N.; Yu, D.C.; Huang, S.C.; Phelps, M.E.

1994-01-01

Racemic β-fluoromethylene-m-tyrosine (FMMl) was developed as an aromatic amino acid decarboxylase (AAAD)- activated monoamine oxidase (MAO) suicide inhibitor. Direct [F-18] fluorination of pure enantiomers, R and S-(E)-β- fluoromethylene-m-tyrosine (E-FMMT) and the racemic geometric isomer R,S(Z)-β-fluoromethylene-m-tyrosine (Z-FMMT) with [F- 18] acetylhypofluorite, afforded 6- and 2[F-18] fluoro positional isomers as the major products. Regioselective radiofluorodestannylation of the respective 4-trimethylstannyl R,S- (E) - FMMT with [F-18]F 2 yielded the 4[F-18] fluoro derivative, thus allowing for the systematic evaluation of the regio- and stereo radiofluorinated AAAD probes. Macacca nemestrina monkeys were injected iv with purified radiofluorinated FMMT analogs and the distribution of activity in the central dopaminergic system was studied with positron emission tomography (PET). Radiofluorinated stereo and geometric FMMT derivatives showed significant differences in their in vivo striatal localization, with radioprobe localization decreasing in the order: 6F-S-(E)-FMMT >> 2F-S-(E)- FMMT >> 4F-R,S-(E)-FMMT. Neither radiofluorinated analogs of R-(E)- FMMT and R,S-(Z)-FMMT showed any significant striatal localization in vivo. (author)

HIP bonding between niobium/copper/stainless steel materials

International Nuclear Information System (INIS)

Inoue, Hitoshi; Fujino, Takeo; Hitomi, Nobuteru; Saito, Kenji; Yamada, Masahiro; Shibuya, Junichi; Ota, Tomoko

2000-01-01

We have used niobium flanges for the niobium bulk superconducting RF cavities, however, they are expensive. Stainless steel flanges instead of the niobium flanges will be used in the future large scale production of sc cavities like the KEK/JAERI joint project. For a future R and D of the vacuum sealing related to the clean horizontal assembly method or development of cavities welded a helium vessel in the KEK/JAERI joint project, a converter section of niobium material to stainless steel is required. From these requirements we need to develop the converter. We have tried a HIP bonding method between niobium materials and stainless steel or copper material. It was made clear that the technology could offer an enough bonding strength even higher than niobium tensile strength in the joined surface between niobium and stainless steel or copper. (author)

Microstructure of super-austenitic steels after long-term annealing

Czech Academy of Sciences Publication Activity Database

Kraus, M.; Kroupa, Aleš; Miodownik, P.; Svoboda, Milan; Vřešťál, J.

2010-01-01

Roč. 101, č. 6 (2010), s. 729-735 ISSN 1862-5282 R&D Projects: GA ČR(CZ) GA106/07/1078 Institutional research plan: CEZ:AV0Z20410507 Keywords : phase equilibria * microstructure * super-austenitic steel Subject RIV: BJ - Thermodynamics Impact factor: 0.860, year: 2010

High yttria ferritic ODS steels through powder forging

Energy Technology Data Exchange (ETDEWEB)

Kumar, Deepak [Department of Metallurgical and Materials Engineering, I.I.T-Roorkee, Uttarakhand 247667 (India); Prakash, Ujjwal, E-mail: ujwalfmt@iitr.ac.in [Department of Metallurgical and Materials Engineering, I.I.T-Roorkee, Uttarakhand 247667 (India); Dabhade, Vikram V. [Department of Metallurgical and Materials Engineering, I.I.T-Roorkee, Uttarakhand 247667 (India); Laha, K.; Sakthivel, T. [Mechanical Metallurgy Group, IGCAR, Kalpakkam, Tamilnadu 603102 (India)

2017-05-15

Oxide dispersion strengthened (ODS) steels are being developed for future nuclear reactors. ODS Fe-18%Cr-2%W-0.2%Ti steels with 0, 0.35, 0.5, 1 and 1.5% Y{sub 2}O{sub 3} (all compositions in weight%) dispersion were fabricated by mechanical alloying of elemental powders. The powders were placed in a mild steel can and forged in a stream of hydrogen gas at 1473 K. The steels were forged again to final density. The strength of ODS steel increased with yttria content. Though this was accompanied by a decrease in tensile elongation, all the steels showed significant ductility. The ductility in high yttria alloys may be attributed to improved inter-particle bonding between milled powders due to reduction of surface oxides by hydrogen. This may permit development of ODS steels with yttria contents higher than the conventional limit of 0.5%. It is suggested that powder forging is a promising route to fabricate ODS steels with high yttria contents and improved ductility. - Highlights: •ODS steels with yttria contents beyond the conventional limit of 0.5 wt% were fabricated by powder forging in a hydrogen atmosphere. •All the alloys exhibited significant ductility. •This may be attributed to improved inter-particle bonding due to reduction of surface oxides by hydrogen. •Strength in excess of 300 MPa was obtained at 973 K for 0.5%, 1% and 1.5% yttria ODS alloys. •Powder forging is a promising route to fabricate ODS steels and permits development of compositions with up to 1.5% yttria.

Brain penetrant small molecule 18F-GnRH receptor (GnRH-R) antagonists: Synthesis and preliminary positron emission tomography imaging in rats

International Nuclear Information System (INIS)

Olberg, Dag E.; Bauer, Nadine; Andressen, Kjetil W.; Hjørnevik, Trine; Cumming, Paul; Levy, Finn O.; Klaveness, Jo; Haraldsen, Ira; Sutcliffe, Julie L.

2016-01-01

Introduction: The gonadotropin releasing hormone receptor (GnRH-R) has a well-described neuroendocrine function in the anterior pituitary. However, little is known about its function in the central nervous system (CNS), where it is most abundantly expressed in hippocampus and amygdala. Since peptide ligands based upon the endogenous decapetide GnRH do not pass the blood–brain-barrier, we are seeking a high-affinity small molecule GnRH-R ligand suitable for brain imaging by positron emission tomography. We have previously reported the radiosynthesis and in vitro evaluation of two novel [ 18 F]fluorinated GnRH-R ligands belonging to the furamide class of antagonists, with molecular weight less than 500 Da. We now extend this work using palladium coupling for the synthesis of four novel radioligands, with putatively reduced polar surface area and hydrophilicity relative to the two previously described compounds, and report the uptake of these 18 F-labeled compounds in brain of living rats. Methods: We synthesized reference standards of the small molecule GnRH-R antagonists as well as mesylate precursors for 18 F-labeling. The antagonists were tested for binding affinity for both human and rat GnRH-R. Serum and blood stability in vitro and in vivo were studied. Biodistribution and PET imaging studies were performed in male rats in order to assess brain penetration in vivo. Results: A palladium coupling methodology served for the synthesis of four novel fluorinated furamide GnRH receptor antagonists with reduced heteroatomic count. Radioligand binding assays in vitro revealed subnanomolar affinity of the new fluorinated compounds for both human and rat GnRH-R. The 18 F-GnRH antagonists were synthesized from the corresponding mesylate precursors in 5–15% overall radiochemical yield. The radiolabeled compounds demonstrated good in vivo stability. PET imaging with the 18 F-radiotracers in naive rats showed good permeability into brain and rapid washout, but absence of

Nano-scaled iron-carbon precipitates in HSLC and HSLA steels

Institute of Scientific and Technical Information of China (English)

2007-01-01

This paper studies the composition, quantity and particle size distribution of nano-scaled precipitates with size less than 20 nm in high strength low carbon (HSLC) steel and their effects on mechanical properties of HSLC steel by means of mass balance calculation of nano-scaled precipitates measured by chemical phase analysis plus SAXS method, high-resolution TEM analysis and thermodynamics calculation, as well as temper rapid cooling treatment of ZJ330. It is found that there existed a large quantity of nano-scaled iron-carbon precipitates with size less than 18 nm in low carbon steel produced by CSP and they are mainly Fe-O-C and Fe-Ti-O-C precipitates formed below temperature A1. These precipitates have ob- vious precipitation strengthening effect on HSLC steel and this may be regarded as one of the main reasons why HSLC steel has higher strength. There also existed a lot of iron-carbon precipitates with size less than 36 nm in HSLA steels.

Nano-scaled iron-carbon precipitates in HSLC and HSLA steels

Institute of Scientific and Technical Information of China (English)

FU Jie; WU HuaJie; LIU YangChun; KANG YongLin

2007-01-01

This paper studies the composition, quantity and particle size distribution of nano-scaled precipitates with size less than 20 nm in high strength Iow carbon (HSLC) steel and their effects on mechanical properties of HSLC steel by means of mass balance calculation of nano-scaled precipitates measured by chemical phase analysis plus SAXS method, high-resolution TEM analysis and thermodynamics calculation, as well as temper rapid cooling treatment of ZJ330. It is found that there existed a large quantity of nano-scaled iron-carbon precipitates with size less than 18 nm in Iow carbon steel produced by CSP and they are mainly Fe-O-C and Fe-Ti-O-C precipitates formed below temperature A1. These precipitates have obvious precipitation strengthening effect on HSLC steel and this may be regarded as one of the main reasons why HSLC steel has higher strength. There also existed a lot of iron-carbon precipitates with size less than 36 nm in HSLA steels.

Analysis of a multi pass weld of a thick walled tube made of austenitic stainless steel X6 CrNiNb 18 10

International Nuclear Information System (INIS)

Scholtes, B.; Zinn, W.; Ilg, U.; Backfisch, W.; Gibmeier, J.; Kirch, D.

2006-01-01

In this paper, microstructure and residual stresses of a multi pass welding of a thick-walled tube made of austenitic stainless steel X6 CrNiNb 18 10 (1.4550) are systematically characterized and assessed. Results of microstructural and phase analyses, residual stress and hardness measurements as well as of a tensile test using micro specimen and SEM analyses are presented. Using these data, plastic deformations occurring during the welding process in the vicinity of the weld seam are evaluated. Finally, consequences of an additional heat treatment at 400 C/24 h are studied. (Abstract Copyright [2006], Wiley Periodicals, Inc.) [de

Deformation behaviour of TRIP steel monitoring by in-situ neutrondiffraction

Czech Academy of Sciences Publication Activity Database

Zrnik, J.; Muránsky, O.; Šittner, Petr; Oliver, E.C.

2011-01-01

Roč. 465, č. 1 (2011), s. 390-394 ISSN 1662-9795 R&D Projects: GA ČR GAP107/10/0824; GA ČR GAP108/10/1296; GA AV ČR(CZ) IAA200100627 Institutional research plan: CEZ:AV0Z10100520 Keywords : TRIP steel * austenite conditioning * retained austenite * neutron diffraction Subject RIV: BM - Solid Matter Physics ; Magnetism http://www.scientific.net/KEM

Evaluation of J-R curve testing of nuclear piping materials using the direct current potential drop technique

International Nuclear Information System (INIS)

Hackett, E.M.; Kirk, M.T.; Hays, R.A.

1986-08-01

A method is described for developing J-R curves for nuclear piping materials using the DC Potential Drop (DCPD) technique. Experimental calibration curves were developed for both three point bend and compact specimen geometries using ASTM A106 steel, a type 304 stainless steel and a high strength aluminum alloy. These curves were fit with a power law expression over the range of crack extension encountered during J-R curve tests (0.6 a/W to 0.8 a/W). The calibration curves were insensitive to both material and sidegrooving and depended solely on specimen geometry and lead attachment points. Crack initiation in J-R curve tests using DCPD was determined by a deviation from a linear region on a plot of COD vs. DCPD. The validity of this criterion for ASTM A106 steel was determined by a series of multispecimen tests that bracketed the initiation region. A statistical differential slope procedure for determination of the crack initiation point is presented and discussed. J-R curve tests were performed on ASTM A106 steel and type 304 stainless steel using both the elastic compliance and DCPD techniques to assess R-curve comparability. J-R curves determined using the two approaches were found to be in good agreement for ASTM A106 steel. The applicability of the DCPD technique to type 304 stainless steel and high rate loading of ferromagnetic materials is discussed. 15 refs., 33 figs

The possibility of tribopair lifetime extending by welding of quenched and tempered stainless steel with quenched and tempered carbon steel

Directory of Open Access Journals (Sweden)

V. Marušić

2015-04-01

Full Text Available In the conditions of tribocorrosion wear, extending of parts lifetime could be achieved by using stainless steel,which is hardened to sufficiently high hardness. In the tribosystem bolt/ bushing shell/link plate of the bucket elevator transporter conveyor machine, the previously quenched and tempered martensitic stainless steel for bolts is hardened at ≈47 HRC and welded with the quenched and tempered high yield carbon steel for bolts. Additional material, based on Cr-Ni-Mo (18/8/6 is used. The microstructure and hardness of welded samples are tested. On the tensile tester, resistance of the welded joint is tested with a simulated experiment. Dimensional control of worn tribosystem elements was performed after six months of service.

Neutron Damage in Steels Containing Small Amounts of Boron

Energy Technology Data Exchange (ETDEWEB)

Myers, H P

1961-05-15

Certain low alloy steels contain small amounts (0.003 to 0.007 w/o) of boron which element contributes to the development of the air hardening properties of these steels. Such steels appear attractive for reactor pressure vessel construction but the question arises whether they will, due to the (n,{alpha}) reaction in boron, be more susceptible to neutron radiation damage than other steels which do not contain boron. We have attempted to estimate the importance of damage arising through boron fission relative to that caused by fast neutrons by assuming that the two sources of damage will be proportional to the numbers of displaced atoms produced in the two processes when no annealing or re combination of defects occurs. Within the approximations used we conclude that in a neutron spectrum which may be represented by an equivalent thermal flux {phi}{sub t} and an equivalent fast flux at 1 MeV of {phi}{sub f}, then D, the ratio of damage to boron fission to that caused by fast neutrons, is D = 4.5 x 10{sup -2} {phi}{sub t}/{phi}{sub f} (for 0. 003 w/o B). For the conditions at the inside of the reactor tank to R3 this would imply D = 1.2 x 10{sup -2} , i.e. if the R3 tank were built with a steel containing 0.003 w/o B then damage due to boron fission would be only {approx} 1 % of that caused by fast neutrons. Further problems with such steels as here discussed are the probability of embrittlement due to the introduction of boron fission fragments lithium and helium and the possibility of a radiation enhanced diffusion of boron which might lead to accentuated slow strain rate embrittlement. We argue that none of these problems should arise. It is concluded that a constructional steel containing 0.003 to 0.007 w/o B should not on this account be more susceptible to radiation damage than other non boron containing steels.

Performance of steel wool fiber reinforced geopolymer concrete

Science.gov (United States)

Faris, Meor Ahmad; Abdullah, Mohd Mustafa Al Bakri; Ismail, Khairul Nizar; Muniandy, Ratnasamy; Ariffin, Nurliayana

2017-09-01

In this paper, performance of geopolymer concrete was studied by mixing of Class F fly ash from Manjung power station, Lumut, Perak, Malaysia with alkaline activator which are combination of sodium hydroxide and sodium silicate. Steel wool fiber were added into the geopolymer concrete as reinforcement with different weight percentage vary from 0 % - 5 %. Chemical compositions of Malaysian fly ash was first analyzed by using X-ray fluorescence. All geopolymer concrete reinforced with steel wool fiber with different weight percentage were tested in terms of density, workability, and compression. Result shows Malaysian fly ash identified by using XRF was class F. Density of geopolymer concrete close to density of OPC which is approximately 2400 kg/m3 and the density was increase gradually with the additions of steel fiber. However, the inclusions of steel fibers also shows some reduction to the workability of geopolymer concrete. Besides, the compressive strength was increased with the increasing of fibers addition until maximum of 18.6 % improvement at 3 % of steel fibers.

Nondestructive evaluation of low carbon steel by magnetic adaptive testing

Czech Academy of Sciences Publication Activity Database

Vértesy, G.; Tomáš, Ivan; Kobayashi, S.

2010-01-01

Roč. 25, č. 2 (2010), s. 125-132 ISSN 1058-9759 R&D Projects: GA ČR GA102/06/0866; GA AV ČR 1QS100100508 Institutional research plan: CEZ:AV0Z10100520 Keywords : magnetic NDE * magnetic adaptive testing * steel * magnetic hysteresis Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 0.771, year: 2010

Stainless Steel Round Robin Test: Centrifugally cast stainless steel screening phase

Energy Technology Data Exchange (ETDEWEB)

Bates, D J; Doctor, S R; Heasler, P G; Burck, E

1987-10-01

This report presents the results of the Centrifugally Cast Stainless Steel Round Robin Test (CCSSRRT). The CCSSRRT is the first phase of an effort to investigate and improve the capability and reliability of NDE inspections of light water reactor piping systems. This phase was a screening test to identify the most promising procedures presently available for CCSS. The next phase will be an in-depth program to evaluate the capability and reliability of inservice inspections (ISI) for piping. In the CCSSRRT, 15 centrifugally cast stainless steel pipe sections containing welds and laboratory-grown thermal fatigue cracks in both columnar and equiaxed base material were used. These pipe specimens were inspected by a total of 18 teams from Europe and the United States using a variety of NDE techniques, mostly ultrasonic (UT). The inspections were carried out at the team's facilities and included inspections from both sides of the weld and inspections restricted to one side of the weld. The results of the CCSSRRT make it apparent that a more detailed study on the capability and reliability of procedures to inspect stainless steel materials is needed to better understand the specific material and flaw properties and how they affect the outcome of an inspection.

The Promotion of Liquid Phase Sintering of Boron-Containing Powder Metallurgy Steels by Adding Nickel

Directory of Open Access Journals (Sweden)

Wu Ming-Wei

2015-01-01

Full Text Available Boron is a feasible alloying element for liquid phase sintering (LPS of powder metallurgy (PM steels. This study investigated the effect of nickel (Ni, which is widely used in PM steels, on the liquid phase sintering of boron-containing PM steels. The results showed that the addition of 1.8wt% Ni does not apparently modify the LPS mechanism of boron-containing PM steels. However, adding 1.8wt% Ni slightly improves the LPS densification from 0.60 g/cm3 to 0.65 g/cm3, though the green density is reduced. Thermodynamic simulation demonstrated that the presence of Ni lowers the temperature region of liquid formation, resulting in enhanced LPS densification. Moreover, original graphite powders remains in the steels sintered at 1200 ºC. These graphite powders mostly dissolve into the base iron powder when the sintering temperature is increased from 1200 ºC to 1250 ºC.

TRIP steel microstructure visualized by slow and very slow electrons

Czech Academy of Sciences Publication Activity Database

Mikmeková, Šárka; Yamada, K.; Noro, H.

2013-01-01

Roč. 62, č. 6 (2013), s. 589-596 ISSN 2050-5698 R&D Projects: GA TA ČR TE01020118 Institutional support: RVO:68081731 Keywords : SLEEM * SEM * crystallographic contrast * surface sensitivity * multi-phase steels * cathode lens mode Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

Synergistic enhancing effect of N+C alloying on cyclic deformation behaviors in austenitic steel

Energy Technology Data Exchange (ETDEWEB)

Kang, J. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Zhang, F.C., E-mail: zfc@ysu.edu.cn [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Long, X.Y. [State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004 (China); Yang, Z.N. [National Engineering Research Center for Equipment and Technology of Cold Strip Rolling, Yanshan University, Qinhuangdao 066004 (China)

2014-07-29

Cyclic plastic and elastic strain controlled deformation behaviors of Mn18Cr7 austenitic steel with N0.6C0.3 synergistic enhancing alloying have been investigated using tension-compression low cycle fatigue and three-point bending high cycle fatigue testing. Results of cyclic deformation characteristic and fatigue damage mechanism have been compared to that in Mn12C1.2 steel. Mn18Cr7N0.6C0.3 steel always shows cyclic softening caused by enhanced planar sliding due to the interaction between N+C and the substitutional atoms as well as the dislocation, which is totally different from cyclic hardening in Mn12C1.2 steel caused by the interaction between C members of C–Mn couples with the dislocation. Enhanced effective stress is obtained due to the solid solution strengthening effect caused by the short range order at low strain amplitude while this effect does not work at high strain amplitude. Internal stress contributes most to the cyclic softening with the increase of strain amplitudes. Significant planar slip characteristic can be observed resulting from low stacking fault energy and high short range order effects in Mn18Cr7N0.6C0.3 steel and finally the parallel or intersecting thin sheets with dislocation tangles separated by dislocation free sheets are obtained with the prolonged cycles under cyclic elastic or plastic strain controlled fatigue testing. There exist amounts of small cracks on the surface of the Mn18Cr7N0.6C0.3 steel because fatigue crack initiation is promoted by the cyclic plastic strain localization. However, the zigzag configuration of the cracks reveals that the fatigue crack propagation is highly inhibited by the planar slip characteristic, which eventually improves the fatigue life.

Increased Expression of Herpes Virus-Encoded hsv1-miR-H18 and hsv2-miR-H9-5p in Cancer-Containing Prostate Tissue Compared to That in Benign Prostate Hyperplasia Tissue

Directory of Open Access Journals (Sweden)

Seok Joong Yun

2016-06-01

Full Text Available Purpose: Previously, we reported the presence of virus-encoded microRNAs (miRNAs in the urine of prostate cancer (CaP patients. In this study, we investigated the expression of two herpes virus-encoded miRNAs in prostate tissue. Methods: A total of 175 tissue samples from noncancerous benign prostatic hyperplasia (BPH, 248 tissue samples from patients with CaP and BPH, and 50 samples from noncancerous surrounding tissues from these same patients were analyzed for the expression of two herpes virus-encoded miRNAs by real-time polymerase chain reaction (PCR and immunocytochemistry using nanoparticles as molecular beacons. Results: Real-time reverse transcription-PCR results revealed significantly higher expression of hsv1-miR-H18 and hsv2-miRH9- 5p in surrounding noncancerous and CaP tissues than that in BPH tissue (each comparison, P<0.001. Of note, these miRNA were expressed equivalently in the CaP tissues and surrounding noncancerous tissues. Moreover, immunocytochemistry clearly demonstrated a significant enrichment of both hsv1-miR-H18 and hsv2-miR-H9 beacon-labeled cells in CaP and surrounding noncancerous tissue compared to that in BPH tissue (each comparison, P<0.05 for hsv1-miR-H18 and hsv2- miR-H9. Conclusions: These results suggest that increased expression of hsv1-miR-H18 and hsv2-miR-H95p might be associated with tumorigenesis in the prostate. Further studies will be required to elucidate the role of these miRNAs with respect to CaP and herpes viral infections.

Microstructure characterization in the weld joint of a high nickel austenitic alloy and Cr18-Ni8 stainless steel

Energy Technology Data Exchange (ETDEWEB)

Wu, Na; Li, Yajiang; Wang, Juan [Shandong Univ., Jinan (CN). Key Lab. for Liquid - Solid Structural Evolution and Processing of Materials (Ministry of Education)

2012-06-15

High nickel austenitic alloy, 6 mm thick, and Cr18-Ni8 stainless steel with a thickness of 0.6 mm were joined by pulsed current tungsten inert gas arc welding without filler metal in this work. Metallographic examination, microhardness measurement and electron microprobe analysis were used to reveal microstructural characteristics in the joint. The results indicated that the weld metal consisted of {gamma}-austenite, {delta}-ferrite and carbides without the appearance of martensite. There were dendrite crystals at the edge of the weld metal near the high nickel austenitic alloy and isometric crystals in the center of the weld metal. The microhardness of the weld metal was the highest due to the existence of carbides and its finer structure. Graphite flakes were still embedded in the austenite matrix of the heat-affected zone without the formation of martensite. (orig.)

Investigation of Cr-Ni duplex stainless steel

International Nuclear Information System (INIS)

Lu Shiying

1985-01-01

At temperatures of 450 - 750 0 C, a laminate-shaped intermetallic phase Fe3Cr3Mo2Si2 has been observed. Intergranular brittle fracture is due to the precipitation of the Fe3Cr3Mo2SI2 phase, but quasi-cleavage fracture is connected with the precipitation of chi and σ phases. The formation of chi and σ during aging at 750 - 900 0 C results in a drastic decrease of the SCC resistance of Cr18Ni5 steel. In order to avoid a fully ferritic microstructure in Cr18Ni5 duplex steel after heating at high temperature or welding, the K value must be kept to 0.42 for thin wall tube. The decrease in SCC resistance after cold deformation is not due to the formation of strain-induced martensite but is connected with significant reduction in the resistance to pitting corrosion. (author)

Creep constitutive equation of dual phase 9Cr-ODS steel

International Nuclear Information System (INIS)

Sakasegawa, Hideo; Ukai, Shigeharu; Tamura, Manabu; Ohtsuka, Satoshi; Tanigawa, Hiroyasu; Ogiwara, Hiroyuki; Kohyama, Akira; Fujiwara, Masayuki

2008-01-01

9Cr-ODS (oxide dispersion strengthened) steels developed by JAEA (Japan Atomic Energy Agency) have superior creep properties compared with conventional heat resistant steels. The ODS steels can enormously contribute to practical applications of fast breeder reactors and more attractive fusion reactors. Key issues are developments of material processing procedures for mass production and creep life prediction methods in present R and D. In this study, formulation of creep constitutive equation was performed against the backdrop. The 9Cr-ODS steel displaying an excellent creep property is a dual phase steel. The ODS steel is strengthened by the δ ferrite which has a finer dispersion of oxide particles and shows a higher hardness than the α' martensite. The δ ferrite functions as a reinforcement in the dual phase 9Cr-ODS steel. Its creep behavior is very unique and cannot be interpreted by conventional theories of heat resistant steels. Alternative qualitative model of creep mechanism was formulated at the start of this study using the results of microstructural observations. Based on the alternative creep mechanism model, a novel creep constitutive equation was formulated using the exponential type creep equation extended by a law of mixture

Magnetic Properties and Structure of Non-Oriented Electrical Steel Sheets after Different Shape Processing

Czech Academy of Sciences Publication Activity Database

Bulín, Tomáš; Švábenská, Eva; Hapla, Miroslav; Ondrůšek, Č.; Schneeweiss, Oldřich

2017-01-01

Roč. 131, č. 4 (2017), s. 819-821 ISSN 0587-4246. [CSMAG 2016 - Czech and Slovak Conference on Magnetism /16./. Košice, 13.06.2016-17.06.2016] R&D Projects: GA TA ČR(CZ) TE02000232 Institutional support: RVO:68081723 Keywords : Magnetic properties * Silicon steel * Steel sheet Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 0.469, year: 2016

Effects of Pseudomonas putida WCS358r and its genetically modified phenazine producing derivative on the Fusarium population in a field experiment, as determined by 18S rDNA analysis

NARCIS (Netherlands)

Leeflang, P.; Smit, E.; Glandorf, D.C.M.; Van Hannen, E.J.; Wernars, K.

2002-01-01

We measured effects of Pseudomonas putida WCS358r and its genetically modified phenazine producing derivative on the Fusarium population in the soil of a wheat field in the Netherlands. We used 18S rDNA analysis to study the Fusarium population through a strategy based on screening clone libraries

Intergranular penetration of liquid gold into stainless steel

OpenAIRE

Favez, Denis; Deillon, Léa; Wagnière, Jean-Daniel; Rappaz, Michel

2011-01-01

Intergranular penetration of liquid 18 K gold into a superaustenitic stainless steel, which occurs during laser welding of these two materials, has been studied using a C-ring device which can be put under tensile stresses by a screw. It is shown that liquid gold at 1000 degrees C penetrates the immersed stainless steel C-ring at grain boundaries, but only when tensile stresses are applied. Based on the thickness of the peritectic phase that forms all along the liquid crack and on the transve...

Monitoring of occupational exposure in manufacturing of stainless steel constructions

Czech Academy of Sciences Publication Activity Database

Kučera, Jan; Bencko, V.; Pápayová, A.; Šaligová, D.; Tejral, J.; Borská, L.

2001-01-01

Roč. 9, - (2001), s. 171-175 ISSN 1210-7778 R&D Projects: GA ČR GV202/97/K038 Institutional research plan: CEZ:AV0Z1048901 Keywords : occupational exposure * stainless steel construction industry * instrumental neutron activation analysis Subject RIV: FP - Other Medical Disciplines

J-R Fracture Resistance of SA533 Gr.B-Cl.1 Steel for Reactor Pressure Vessel

Energy Technology Data Exchange (ETDEWEB)

Yoon, Ji-Hyun; Hong, Seokmin; Lee, Bong-Sang [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

A rolled plate might show different mechanical behaviors from a forging, even though they contain same chemical compositions. Furthermore, it is known that the fracture behavior of a rolled plate is very sensitive to material orientation comparing to a forging. In this study, the J-R fracture resistances of SA533 Gr.B-Cl.1 plate were measured at reactor operating temperature and the material orientation sensitivity was discussed. The decrease of fracture resistance of this kind of low alloy steel at an elevated temperature is known as the effect of dynamic strain aging (DSA). It was attributed to that the carbides and grains elongated to primary rolling direction, so that the aspect ratio of carbides and grains in the specimen with T-L orientation is larger. Generally, the hard second phase could take a roll of trigger point of unstable fracture. It is needed that the fracture surfaces of the tested specimens to be examined profoundly.

CASTOR(r) and CONSTOR(r) type transport and storage casks for spent fuel and high active waste

International Nuclear Information System (INIS)

Kuehne, B.; Sowa, W.

2002-01-01

The German company GNB has developed, tested, licensed, fabricated, loaded, transported and stored a large number of casks for spent fuel and high-level waste. CASTOR(r) casks are used at 18 sites on three continents. Spent fuel assemblies of the types PWR, BWR, VVER, RBMK, MTR and THTR as well as vitrified high active waste (HAW) containers are stored in these kinds of casks. More than 600 CASTOR(r) casks have been loaded for long-term storage. The two decades of storage have shown that the basic requirements, which are safe confinement, criticality safety, sufficient shielding and appropriate heat transfer have been fulfilled in each case. There is no indication that problems will arise in the future. Of course, the experience of 20 years has resulted in improvements of the cask design. One basic improvement is GNB's development since the mid 1990s of a sandwich cask design using heavy concrete and steel as basic materials, for economical and technical reasons. This CONSTOR(r) cask concept also fulfils all design criteria for transport and storage given by the IAEA recommendations and national authorities. By May 2002 40 CONSTOR(r) casks had been delivered and 15 had been successfully loaded and stored. In this paper the different types of casks are presented. Experiences gained during the large number of cask loadings and more than 4000 cask-years of storage will be summarised. The presentation of recent and future development shows the optimisation potential of the CASTOR(r) and CONSTOR(r) cask families for safe and economical management of spent fuel. (author)

Corrosion resistance of chromium-nickel steel containing rare earths

International Nuclear Information System (INIS)

Asatiani, G.N.; Mandzhgaladze, S.N.; Tavadze, L.F.; Chuvatina, S.N.; Saginadze, D.I.

1983-01-01

Effect of additional out-of-furnace treatment with complex alloy (foundry alloy) calcite-silicon-magnesium-rare earth metal on corrosion resistance of the 03Kh18N20M3D3C3B steel has been studied. It is shown that introduction of low additions of rare earths improves its corrosion resistance improves its corrosion resistance in agressive media (in 70% - sulfuric acid) in the range of transition from active to passive state. Effect of additional introduction of rare earth metals is not considerable, if potential of steel corrosion is in the range of stable passive state (32% - sulfuric acid). Additional out-of-furnace treatment with complex foundry alloy, containing rare earth metals, provides a possibility to use a steel with a lower content of Cr, Ni, Mo, than in conventional acid-resistant steels in highly agressive media

Comparative study between two austenitic steels with the EPR (Electrochemical Potentiokinetic Reactivation) technique

International Nuclear Information System (INIS)

Guillen M, A.N.

1997-01-01

In the mid 19704s, the intergranular corrosion with stress corrosion cracking (IGSCC) have been identified as a greater problem in Boiling Water Reactors BWR in several places of the world. The Electrochemical Potentiokinetic Reactivation - Single Loop (EPR-SL) test and the Double Loop (EPR-DL) test, were developed as methods for measuring the Degree of Sensitization (DOS), show sensitised materials at subject to Intergranular Corrosion. In Mexico, the Laguna Verde4s reactor is BWR type and many of its principal components was built with AISI 304 stainless steels, while that in VVER reactors as well as Juragua4s reactor in Cuba is used 321 Stainless stell in its Russian equivalent designation 08Ch18N10T. In this work, were studied 304 and 08Ch18N10T stainless steels by means of EPR-SL, EPR-DL and ASTM A-262 techniques, they have been found a good correlation for 304 steel but not in 08Ch18N10T steel and was proposed one modification in the criterion by the evaluation on the sensitisation in this steels. Finally, both materials were welded with procedures used in the nuclear industry, by Slow Strain Rate Test (SSRT) to determine the Stress Corrosion Cracking SCC susceptibility, and subsequently the susceptibility to localized corrosion was studied by means of Cyclic Polarization test and the uniform corrosion rate in a solution with chlorides by the Tafel plot, Potentiodynamic Anodic Polarization Resistance. (Author)

On the nature of anomalies in temperature dependence of the OKh18N1OT steel yield strength after thermal cycling in the low temperature range

International Nuclear Information System (INIS)

Medvedev, E.M.; Lavrent'ev, F.F.; Kurmanova, T.N.

1978-01-01

Investigated were structural transformations in 0Kh18N10T steel as a result of heating and cooling and of deformation within the range of temperatures between 300 and 77 K, the quantity relationships between the said transformations and the variation of the yield limit with the temperature. The studies were conducted by metallography and mechanical test methods. It was shown that an increase in the number of heating and cooling cycles correlates with a loss in strength of the steel while deformation at 77 K. This anomaly in the temperature relationship of the yield limit is related to the appearance in the course of deformation of α-martensite with a BCC lattice. Deformation at 300 K increases the amount ea of epsilon-martensite, a decrses the effectve size of grain and, in consequence, increases the yield limit. The relationship between the yield limit and the grain size at the temperature of 300 K is described adequately by the Hall-Petch equation

Effect of heat treatment regime on structural lamination in ferritic-austenitic steels

International Nuclear Information System (INIS)

Sizov, R.A.; Zakharova, M.I.; Novikov, I.I.; Bannykh, O.A.

1983-01-01

The effect of preliminary thermal treatment on lamination and viscosity of EhP-53 and KO-3 steels after durable aging at the temperature of 350 is studied. It is shown that preliminary heat treatment considerably affects lamination processes in the result of aging of 0Kh18G8N2T steel. The lowest rate of lamination and higher impact strength after aging at 350 deg C for 4500 hours corresponds to the following heat treatment: 10 hour aging at 650 deg C with cooling in the air, then quenching in water from 950 deg C after aging for 30 min and the following tempering (650 deg C, 5 hours). Unlike the 0Kh18G8N2T steel, lamination parameters of steel 0Kh22N6T practically do not change after the application of heat treatment. Nevertherless, taking into account results of impact strength, it is advisable to have thermal treatment according to the regime: quenching in water at 950 deg C after aging for 30 min

Multiaxial elastoplastic cyclic loading of austenitic 316L steel

Czech Academy of Sciences Publication Activity Database

Mazánová, Veronika; Polák, Jaroslav; Škorík, Viktor; Kruml, Tomáš

2017-01-01

Roč. 11, č. 40 (2017), s. 162-169 ISSN 1971-8993 R&D Projects: GA ČR(CZ) GA13-23652S; GA MŠk LM2015069; GA MŠk(CZ) LQ1601; GA ČR GA15-08826S Institutional support: RVO:68081723 Keywords : 316L steel * Crack initiation * Cyclic stress-strain curve * Multiaxial cyclic loading Subject RIV: JL - Materials Fatigue, Friction Mechanics OBOR OECD: Audio engineering, reliability analysis

Fatigue behaviour of X70 steel in crude oil

Czech Academy of Sciences Publication Activity Database

Gajdoš, Lubomír; Šperl, Martin; Bystrianský, J.

2015-01-01

Roč. 49, č. 2 (2015), s. 243-246 ISSN 1580-2949 R&D Projects: GA ČR(CZ) GAP105/10/2052; GA TA ČR(CZ) TE02000162 Institutional support: RVO:68378297 Keywords : corrosion fatigue * S-N curve * X70 steel * crude oil * separated water Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 0.439, year: 2015 http://mit.imt.si/Revija/izvodi/mit152/gajdos.pdf

Assessment of martensitic steels for advanced fusion reactors

International Nuclear Information System (INIS)

Wareing, J.; Tavassoli, A.A.

1995-01-01

Martensitic steels are currently considered in Europe to be prime structural candidate materials for the first wall and breeding blanket of the DEMO fusion reactor. In this design, reactor power and wall loading will be significantly higher than those of an experimental reactor. ITER and will give rise to component operating temperatures in the range 250 to 550 0 C with neutron doses higher than 70 dpa. These conditions render austenitic stainless steel, which will be used in ITER, less favourable. Factors contributing to the promotion of martensitic steels are their excellent resistance to irradiation induced swelling, low thermal expansion and high thermal conductivity allied to advanced industrial maturity, compared to other candidate materials vanadium alloys. This paper described the development and optimisation of the steel and weld metal. Using data design rules generated on modified 9 Cr 1 Mo steel during its qualification as a steam generator material for the European Fast Reactor (EFR), interim design guidelines are formulated. Whilst the merits of the steel are validated, it is shown that irradiation embrittlement at low temperature, allied to the need for prolonged post-weld hat treatment and the long term creep response of welds remain areas of some concern. (author). 18 refs., 6 figs., 2 tabs

Modified Monkman–Grant relationship for austenitic stainless steel foils

Energy Technology Data Exchange (ETDEWEB)

Osman Ali, Hassan, E-mail: hassaninsan@gmail.com [Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor (Malaysia); Tamin, Mohd Nasir, E-mail: taminmn@fkm.utm.my [Faculty of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor (Malaysia)

2013-02-15

Characteristics of creep deformation for austenitic stainless steel foils are examined using the modified Monkman–Grant equation. A series of creep tests are conducted on AISI 347 steel foils at 700 °C and different stress levels ranging from 54 to 221 MPa. Results showed that at lower stress levels below 110 MPa, the creep life parameters ε{sub min},ε{sub r},t{sub r} can be expressed using the modified Monkman–Grant equation with exponent m′= 0.513. This indicates significant deviation of the creep behavior from the first order reaction kinetics theory for creep (m′ = 1.0). The true tertiary creep damage in AISI 347 steel foil begins after 65.9% of the creep life of the foil has elapsed at stress levels above 150 MPa. At this high stress levels, Monkman–Grant ductility factor λ{sup ′} saturates to a value of 1.3 with dislocation-controlled deformation mechanisms operating. At low stress levels, λ{sup ′} increases drastically (λ{sup ′}=190 at 54 MPa) when slow diffusion-controlled creep is dominant.

Investigation of corrosion resistance of 18Cr-14NNi-1.5Si austenitic steel in molten PbBi eutectic

International Nuclear Information System (INIS)

Rivai, A.K.; Heinzel, H.; Effendi, N.

2013-01-01

Full-text: The development of high corrosion resistant materials for the fuel cladding and structural materials in liquid lead-bismuth (Pb-Bi) eutectic environment especially at high temperature is a critical issue for the deployment of LFR (Lead alloy-cooled fast reactor) and ADS (Accelerator driven Transmutation System). Pb-Bi eutectic is a coolant for LFR which is one of the future nuclear reactors in the world (Generation IV reactors), and also a spallation target material and a coolant for ADS. In this study, corrosion test of an austenitic steel was done in COSTA Pb-Bi eutectic corrosion test facility at Pulsed Power and Microwave Technology, Karlsruhe Institute of Technology, Germany. The sample was an 18Cr-14Ni-1.5Si austenitic steel which has been developed in Center For Technology of Nuclear Industry Materials, Indonesian National Nuclear Energy Agency. The test was done in stagnant molten Pb-Bi eutectic at 550 degree Celsius of temperature for about 300 hours with an oxygen concentration of 1 x 10 -6 wt %. The characterization was carried out using OM (Optical Microscope), SEM-EDS (Scanning Electron Microscope and Energy Dispersive X-ray Spectroscope) and AFM (Atomic Force Microscope). The corrosion test result showed the formation of a duplex oxide layer for example an outer iron oxide layer with about 3-3.4 μm in thickness. Furthermore, there was no penetration of Pb-Bi into the bulk of the specimen because of the protection from the protective oxide layer. (author)

Biological significance of 5S rRNA import into human mitochondria: role of ribosomal protein MRP-L18

Science.gov (United States)

Smirnov, Alexandre; Entelis, Nina; Martin, Robert P.; Tarassov, Ivan

2011-01-01

5S rRNA is an essential component of ribosomes of all living organisms, the only known exceptions being mitochondrial ribosomes of fungi, animals, and some protists. An intriguing situation distinguishes mammalian cells: Although the mitochondrial genome contains no 5S rRNA genes, abundant import of the nuclear DNA-encoded 5S rRNA into mitochondria was reported. Neither the detailed mechanism of this pathway nor its rationale was clarified to date. In this study, we describe an elegant molecular conveyor composed of a previously identified human 5S rRNA import factor, rhodanese, and mitochondrial ribosomal protein L18, thanks to which 5S rRNA molecules can be specifically withdrawn from the cytosolic pool and redirected to mitochondria, bypassing the classic nucleolar reimport pathway. Inside mitochondria, the cytosolic 5S rRNA is shown to be associated with mitochondrial ribosomes. PMID:21685364

EELS study of the inverse martensitic transformation of 2H and 18R Cu-Al-Zn alloys

International Nuclear Information System (INIS)

Espinosa-Magana, F.; Ochoa-Lara, M.T.; Lovey, F.; Flores-Zuniga, H.; Rios-Jara, D.

2010-01-01

Changes in 3d states occupancy associated with the inverse martensitic transformation in two samples of Cu-Al-Zn alloys with 2H and 18R martensitic structures were investigated by electron energy loss spectroscopy (EELS). The Cu L 2,3 white-lines intensities, which reflect the unoccupied density of states in 3d bands, were measured in situ, during the phase transformation in both the martensite and austenite phases. We find that the white-lines intensity decreases during the inverse transformation, when going from martensite to austenite. Even though the initial 3d occupation numbers in 2H and 18R martensitic structures are different, after the transformation, the 3d occupation numbers in the now austenitic structure have decreased in both samples, indicating that some electrons left Cu 3d bands during phase transformation. Interestingly enough, the occupation numbers in the final phases, which have the same structure, reach the same value, indicating that changes in EELS spectra are a consequence of structural changes.

EELS study of the inverse martensitic transformation of 2H and 18R Cu-Al-Zn alloys

Energy Technology Data Exchange (ETDEWEB)

Espinosa-Magana, F., E-mail: francisco.espinosa@cimav.edu.m [Centro de Investigacion en Materiales Avanzados, S.C., Laboratorio Nacional de Nanotecnologia, Miguel de Cervantes 120, Complejo Industrial Chihuahua, Chihuahua, Chih. 31109 (Mexico); Ochoa-Lara, M.T. [Centro de Investigacion en Materiales Avanzados, S.C., Laboratorio Nacional de Nanotecnologia, Miguel de Cervantes 120, Complejo Industrial Chihuahua, Chihuahua, Chih. 31109 (Mexico); Lovey, F. [Centro Atomico Bariloche, 8300 S.C. de Bariloche (Argentina); Flores-Zuniga, H. [Universidad Autonoma de Zacatecaa, Av. Lopez Velarde 801, Zacatecas, Zac. 98060 (Mexico); Rios-Jara, D. [Instituto Potosino de Investigacion Cientifica y Tecnologica, Camino a la Presa San Jose 2055, San luis Potosi, S.L.P. 78126 (Mexico)

2010-01-01

Changes in 3d states occupancy associated with the inverse martensitic transformation in two samples of Cu-Al-Zn alloys with 2H and 18R martensitic structures were investigated by electron energy loss spectroscopy (EELS). The Cu L{sub 2,3} white-lines intensities, which reflect the unoccupied density of states in 3d bands, were measured in situ, during the phase transformation in both the martensite and austenite phases. We find that the white-lines intensity decreases during the inverse transformation, when going from martensite to austenite. Even though the initial 3d occupation numbers in 2H and 18R martensitic structures are different, after the transformation, the 3d occupation numbers in the now austenitic structure have decreased in both samples, indicating that some electrons left Cu 3d bands during phase transformation. Interestingly enough, the occupation numbers in the final phases, which have the same structure, reach the same value, indicating that changes in EELS spectra are a consequence of structural changes.

Characterization of rapidly solidified powder of high-speed steel

Czech Academy of Sciences Publication Activity Database

Miglierini, M.; Lančok, Adriana; Kusý, M.

2009-01-01

Roč. 190, 1-3 (2009), s. 51-57 ISSN 0304-3843 R&D Projects: GA ČR GP203/07/P011 Grant - others:GA(SK) VEGA1/3190/06 Institutional research plan: CEZ:AV0Z40320502 Keywords : Rapidly solidified powder * Tool steel * Mössbauer spectroscopy Subject RIV: CA - Inorganic Chemistry Impact factor: 0.209, year: 2007

Investigation of hot cracking resistance of 2205 duplex steel

Energy Technology Data Exchange (ETDEWEB)

Adamiec, J; Scibisz, B, E-mail: janusz.adamiec@polsl.pl [Silesian University of Technology, Faculty of Materials Science and Metallurgy, ul. Krasinskiego 8, PL-40019 Katowice (Poland)

2010-02-15

Austenitic duplex steel of the brand 2205 according to Avesta Sheffield is used for welded constructions (pipelines, tanks) in the petrol industry, chemical industry and food industry. It is important to know the range of high-temperature brittleness in designing welding technology for constructions made of this steel type. There is no data in literature concerning this issue. High-temperature brittleness tests using the simulator of heat flow device Gleeble 3800 were performed. The tests results allowed the evaluation of the characteristic temperatures in the brittleness temperature range during the joining of duplex steels, specifically the nil-strength temperature (NST) and nil-ductility temperatures (NDT) during heating, the strength and ductility recovery temperatures (DRT) during cooling, the R{sub f}parameter (R{sub f} = (T{sub liquidus} - NDT)/NDT) describing the duplex steel inclination for hot cracking, and the brittleness temperature range (BTR). It has been stated that, for the examined steel, this range is wide and amounts to ca. 90 deg. C. The joining of duplex steels with the help of welding techniques creates a significant risk of hot cracks. After analysis of the DTA curves a liquidus temperature of T{sub L} = 1465 deg. C and a solidus temperature of T{sub S} = 1454 deg. C were observed. For NST a mean value was assumed, in which the cracks appeared for six samples; the temperature was 1381 deg. C. As the value of the NDT temperature 1367 deg. C was applied while for DRT the assumed temperature was 1375 deg. C. The microstructure of the fractures was observed using a Hitachi S-3400N scanning electron microscope (SEM). The analyses of the chemical composition were performed using an energy-dispersive X-ray spectrometer (EDS), Noran System Six of Thermo Fisher Scientific. Essential differences of fracture morphology type over the brittle temperature range were observed and described.

Investigation of hot cracking resistance of 2205 duplex steel

International Nuclear Information System (INIS)

Adamiec, J; Scibisz, B

2010-01-01

Austenitic duplex steel of the brand 2205 according to Avesta Sheffield is used for welded constructions (pipelines, tanks) in the petrol industry, chemical industry and food industry. It is important to know the range of high-temperature brittleness in designing welding technology for constructions made of this steel type. There is no data in literature concerning this issue. High-temperature brittleness tests using the simulator of heat flow device Gleeble 3800 were performed. The tests results allowed the evaluation of the characteristic temperatures in the brittleness temperature range during the joining of duplex steels, specifically the nil-strength temperature (NST) and nil-ductility temperatures (NDT) during heating, the strength and ductility recovery temperatures (DRT) during cooling, the R f parameter (R f = (T liquidus - NDT)/NDT) describing the duplex steel inclination for hot cracking, and the brittleness temperature range (BTR). It has been stated that, for the examined steel, this range is wide and amounts to ca. 90 deg. C. The joining of duplex steels with the help of welding techniques creates a significant risk of hot cracks. After analysis of the DTA curves a liquidus temperature of T L = 1465 deg. C and a solidus temperature of T S = 1454 deg. C were observed. For NST a mean value was assumed, in which the cracks appeared for six samples; the temperature was 1381 deg. C. As the value of the NDT temperature 1367 deg. C was applied while for DRT the assumed temperature was 1375 deg. C. The microstructure of the fractures was observed using a Hitachi S-3400N scanning electron microscope (SEM). The analyses of the chemical composition were performed using an energy-dispersive X-ray spectrometer (EDS), Noran System Six of Thermo Fisher Scientific. Essential differences of fracture morphology type over the brittle temperature range were observed and described.

Microstructural stability of ODS steels in cyclic loading

Czech Academy of Sciences Publication Activity Database

Kuběna, Ivo; Polák, Jaroslav; Płociński, T.; Hébert, C.; Škorík, Viktor; Kruml, Tomáš

2015-01-01

Roč. 38, č. 8 (2015), s. 936-947 ISSN 8756-758X R&D Projects: GA MŠk(CZ) ED1.1.00/02.0068; GA MŠk(CZ) EE2.3.30.0063; GA ČR(CZ) GA13-23652S; GA ČR(CZ) GP13-28685P Institutional support: RVO:68081723 Keywords : steel * microstructure * fatigue Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 1.838, year: 2015 http://onlinelibrary.wiley.com/doi/10.1111/ffe.12284/abstract

PERAN BUDAYA ORGANISASI TERHADAP DISIPLIN KERJA KARYAWAN DIREKTORAT PRODUKSI PT KRAKATAU STEEL (PERSERO TBK CILEGON

Directory of Open Access Journals (Sweden)

Muhammad Luhung Pribadi

2016-12-01

Full Text Available This research aims to study the effect of organizational culture toward  employee work discipline at Directorate Production PT Krakatau Steel (Persero Tbk Cilegon. The subjects of this research are 115 employees from several divisions at Directorate Production of PT Krakatau Steel (Persero Tbk Cilegon. The data were collected through cluster sampling technique. Instrument used are  organizational culture scale, and work discipline scale. Data were  analized using correlational test regression analysis technique. The result show that there is significant correlation of organizational culture for employee work discipline at Directorate Production PT Krakatau Steel (Persero Tbk Cilegon. It is shown by correlation coefficient of regression analysis as R=0,534, with effective contribution R square (R2= 0,285 or 28,5%, and significance level p = 0,000. Thus, it proves the hypothesis in this research is accepted.

Aluminide protective coatings on high–temperature creep resistant cast steel

OpenAIRE

J. Kubicki; A. Kochmańska

2009-01-01

This paper presents the results of research on aluminide protective coatings manufactured on high–temperature creep resistant cast steel. The main purpose of these coatings is protection against the high temperature corrosion, especially at high carburizing potential atmosphere. Coatings were obtained on cast steel type G–XNiCrSi36–18 with the following methods: pack cementation, paste method, cast method and slurry cementation. The phase composition, thickness and morphology of coatings were...

Development of stainless steels for nuclear power plant - Advanced nuclear materials development -

International Nuclear Information System (INIS)

Hong, Jun Hwa; Ryu, Woo Seog; Chi, Se Hwan; Lee, Bong Sang; Oh, Yong Jun; Byun, Thak Sang; Oh, Jong Myung

1994-07-01

This report reviews the status of R and D and the material specifications of nuclear components in order to develop the stainless steels for nuclear applications, and the technology of computer-assisted alloy design is developed to establish the thermodynamic data of Fe-Cr-Ni-Mo-Si-C-N system which is the basic stainless steel systems. High strength and corrosion resistant stainless steels, 316LN and super clean 347, are developed, and the manufacturing processes and heat treatment conditions are determined. In addition, a martensitic steel is produced as a model alloy for turbine blade, and characterized. The material properties showed a good performance for nuclear applications. (Author)

Heating temperature effect on ferritic grain size of rotor steel

International Nuclear Information System (INIS)

Cheremnykh, V.G.; Derevyankin, E.V.; Sakulin, A.A.

1983-01-01

The heating temperature effect on ferritic grain size of two steels 13Kh1M1FA and 25Kh1M1FA is evaluated. It is shown that exposure time increase at heating temperatures below 1000 deg C up to 10h changes but slightly the size of the Cr-Mo-V ferritic grain of rotor steel cooled with 25 deg C/h rate. Heating up to 1000 deg C and above leads to substantial ferritic grain growth. The kinetics of ferritic grain growth is determined by the behaviour of phases controlling the austenitic grain growth, such as carbonitrides VCsub(0.14)Nsub(0.78) in 13Kh1M1FA steel and VCsub(0.18)Nsub(0.72) in 25Kh1M1FA steel. Reduction of carbon and alloying elements content in steel composition observed at the liquation over rotor length leads to a certain decrease of ferritic grain resistance to super heating

Specific features of precipitation hardening of austenitic steels with various base. 2. Kinetics and mechanism of carbide precipitation

International Nuclear Information System (INIS)

Kositsyna, I.I.; Sagaradze, V.V.; Khakimova, O.N.

1997-01-01

Electron microscopic studies were carried out to determine the kinetics and mechanisms of precipitation hardening in Fe-Mn, Fe-Mn-Cr, Fe-Cr-Mn-N, Fe-Cr-Ni and Fe-Ni base stainless steels (45G20M2F2, 50Kh16G15N6M2F2, 45Kh18N10G10M2F2, 40Kh18Ni18M2F2, 45N26M2F2). The steels were heat treated under various conditions. It is revealed that in manganese steels the particles of vanadium carbide nucleate according to homogeneous mechanism at all aging temperatures (600-750 deg C). The presence of chromium in the matrix promotes the transition to heterogeneous mechanism of carbide nucleation and growth. With nickel content increasing the plasticity of precipitation hardened steels gets better due to more intense diffusion of atoms and vacancies to grain boundaries and, hence, the widening of near-boundary zones free of carbide particles

Overload effects on a ferritic-baintic steel and a cast aluminium alloy: two very different behaviours

Energy Technology Data Exchange (ETDEWEB)

Saintier, N. [Arts et Metiers Paris Tech, I2M, UMR CNRS, Universite Bordeaux 1, Talene Cedex (France); El Dsoki, C.; Kaufmann, H.; Sonsino, C.M. [Fraunhofer-Institute for Structural Durability and System Reliability LBF, Darmstadt (Germany); Dumas, C. [RENAULT, Technocentre, Guyancourt Cedex (France); Voellmecke, F.J. [BORBET GmbH, Hallenberg-Hesborn (Germany); Palin-Luc, T.; Bidonard, H.

2011-10-15

Load controlled fatigue tests were performed up to 10{sup 7} cycles on flat notched specimens (K{sub t} = 2.5) under constant amplitude and variable amplitude loadings with and without periodical overloads. Two materials are studied: a ferritic-bainitic steel (HE400M steel) and a cast aluminium alloy (AlSi7Mg0.3). These materials have a very different cyclic behaviour: the steel exhibits cyclic strain softening whereas the Al alloy shows cyclic strain hardening. The fatigue tests show that, for the steel, periodical overload applications reduce significantly the fatigue life for fully reversed load ratio (R{sub {sigma}} = -1), while they have no influence under pulsating loading (R{sub {sigma}} = 0). For the Al alloy overloads have an effect (fatigue life decreasing) only for variable amplitude loadings. The detrimental effect of overloads on the steel is due to ratcheting at the notch root which evolution is overload's dependent. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Stainless steel recycle FY94 progress report

International Nuclear Information System (INIS)

Imrich, K.J.

1994-01-01

The Materials Technology Section (MTS) of the Savannah River Technology Center (SRTC) was asked to demonstrate the practicality of recycling previously contaminated stainless steel components such as reactor heat exchanger heads, process water piping and slug buckets into 208 liters (55 gallon) drums and 2.8 cubic meter (100 ft 3 ) storage boxes. Radioactively contaminated stainless steel scrap will be sent to several industrial partners where it will be melted, decontaminated/cast into ingots, and rolled into plate and sheet and fabricated into the drums and boxes. As part of this recycle initiative, MTS was requested to demonstrate that radioactively contaminated Type 304L stainless steel could be remelted and cast to meet the applicable ASTM specification for fabrication of drums and boxes. In addition, MTS was requested to develop the technical basis of melt decontamination and establish practicality of using this approach for value added products. The findings presented in this investigation lead to the following conclusions: recycle of 18 wt% Cr-8 wt% Ni alloy can be achieved by melting Type 304 stainless steel in a air vacuum induction furnace; limited melt decontamination of the contaminated stainless steel was achieved, surface contamination was removed by standard decontamination techniques; carbon uptake in the as-cast ingots resulted from the graphite susceptor used in this experiment and is unavoidable with this furnace configuration. A new furnace optimized for melting stainless steel has been installed and is currently being tested for use in this program

Influence of microstructure of high-strength low-alloy steels on their weldability

International Nuclear Information System (INIS)

Cwiek, J.; Labanowski, J.

2003-01-01

Microstructure of steel before welding has influence on the steel's susceptibility to cold cracking because it influences hardenability and maximum hardness of heat affected zone (HAZ). Two high-strength low-alloy (HSLA) steel grades 18G2AV and 14HNMBCu, in various heat treatment conditions, were subjected to simulated welding thermal cycles. It was revealed that maximum HAZ hardness is influenced by microstructure presented before thermal cycle was applied. The higher HAZ hardness was observed for quenched and tempered condition, comparing to full annealed and overheated conditions. (author)

Evaluation of dynamic fracture toughness of cold worked 9Cr-1Mo steel

International Nuclear Information System (INIS)

Sathyanarayanan, S.; Sasikala, G.; Ray, S.K.

2004-01-01

Dynamic J-R curves for cold worked 9Cr-1Mo steel have been estimated from instrumented impact test data at ambient temperature on pre-cracked Charpy specimens using three methods of analysis, namely those by Ray et al., Schindler, and Sreenivasan and Mannan. It is concluded that of these three, Schindler's method is the best suited for the purpose since it gives consistent variations with cold work of dynamic J-R curves and dynamic fracture toughness. Cold work results in substantial degradation in dynamic fracture toughness of 9Cr-1Mo steel

Microstructure stability and creep behaviour of advanced high chromium ferritic steels

Czech Academy of Sciences Publication Activity Database

Sklenička, Václav; Kuchařová, Květa; Kudrman, J.; Svoboda, Milan; Kloc, Luboš

43 2005, č. 1 (2005), s. 20-33 ISSN 0023-432X R&D Projects: GA ČR(CZ) GA106/02/0608; GA AV ČR(CZ) IAA2041101; GA AV ČR(CZ) 1QS200410502 Institutional research plan: CEZ:AV0Z20410507 Keywords : 9-12%Cr steels * microstructure stability * creep behaviour * nonsteady creep loading Subject RIV: JG - Metallurgy Impact factor: 0.973, year: 2005

Loss of the polycomb protein Mel-18 enhances the epithelial-mesenchymal transition by ZEB1 and ZEB2 expression through the downregulation of miR-205 in breast cancer.

Science.gov (United States)

Lee, J-Y; Park, M K; Park, J-H; Lee, H J; Shin, D H; Kang, Y; Lee, C H; Kong, G

2014-03-06

The epithelial-mesenchymal transition (EMT) is the pivotal mechanism underlying the initiation of cancer invasion and metastasis. Although Mel-18 has been implicated in several biological processes in cancer, its function in the EMT of human cancers has not yet been studied. Here, we demonstrate that Mel-18 negatively regulates the EMT by epigenetically modulating miR-205. We identified miR-205 as a novel target of Mel-18 using a microRNA microarray analysis and found that Mel-18 increased miR-205 transcription by the inhibition of DNA methyltransferase-mediated DNA methylation of the miR-205 promoter, thereby downregulating its target genes, ZEB1 and ZEB2. Furthermore, the loss of Mel-18 promoted ZEB1- and ZEB2-mediated downregulation of E-cadherin transcription and also enhanced the expression of mesenchymal markers, leading to increased migration and invasion in MCF-7 cells. In MDA-MB-231 cells, Mel-18 overexpression restored E-cadherin expression, resulting in reduced migration and invasion. These effects were reversed by miR-205 overexpression or inhibition. A tumor xenograft with Mel-18 knockdown MCF-7 cells consistently showed increased ZEB1 and ZEB2 expression and decreased E-cadherin expression. Taken together, these results suggest that Mel-18 functions as a tumor suppressor by its novel negative control of the EMT, achieved through regulating the expression of miR-205 and its target genes, ZEB1 and ZEB2.

Chromium surface alloying of structural steels during laser treatment

International Nuclear Information System (INIS)

Kurov, I.E.; Nagornykh, S.N.; Sivukhin, G.A.; Solenov, S.V.

1987-01-01

Results of matrix alloying from the surface layer and creation of considerably increased chromium concentration in the depth which permits to increase the efficiency of laser treatment of steels (12Kh18N10T and 38KhN3M) in the process of their further mechanical polishing, are presented. The treatment was realized by continuous CO 2 -laser at different power densities and scanning rates are presented. A model describing the creation of anomalous distributions of the alloying element in steels is plotted

Thermomechanical fatigue and damage mechanisms in Sanicro 25 steel

Czech Academy of Sciences Publication Activity Database

Petráš, Roman; Škorík, Viktor; Polák, Jaroslav

2016-01-01

Roč. 650, JAN (2016), s. 52-62 ISSN 0921-5093 R&D Projects: GA MŠk(CZ) EE2.3.30.0063; GA ČR(CZ) GA13-23652S Institutional support: RVO:68081723 Keywords : thermomechanical fatigue * Sanicro 25 steel * damage mechanism * FIB cutting * localized oxidation-cracking Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 3.094, year: 2016

Retrieval of a million high-quality, full-length microbial 16S and 18S rRNA gene sequences without primer bias

DEFF Research Database (Denmark)

Karst, Søren Michael; Dueholm, Morten Simonsen; McIlroy, Simon Jon

2018-01-01

Small subunit ribosomal RNA (SSU rRNA) genes, 16S in bacteria and 18S in eukaryotes, have been the standard phylogenetic markers used to characterize microbial diversity and evolution for decades. However, the reference databases of full-length SSU rRNA gene sequences are skewed to well-studied e...

A new and unusual deformation behavior observed in 12Cr18Ni10Ti stainless steel irradiated at 307 deg. C to 55 dpa in BN-350

International Nuclear Information System (INIS)

Gusev, M.; Maksimkin, O.; Osipov, I.S.; Garner, F.

2007-01-01

Full text of publication follows: It is currently accepted that neutron irradiation of stainless steels in general leads to increased strength, reduction of ductility and inevitably to embrittlement. The microstructural origins of such changes in mechanical behavior are well understood. Occasionally, however, a new phenomenon is observed at higher fluences. Void-induced embrittlement is an example whereby the ductility loss is strongly accelerated when new microstructural conditions develop from voids that cause stress concentration, removal of nickel from the matrix and thereby induce a martensitic transformation. This process occurs at moderately high temperatures where high void swelling can occur. It now appears that there is another, previously unobserved phenomenon that develops in austenitic steel irradiated to relatively high dose and relatively low temperature. In this case, however, the loss of plasticity commonly developed at lower dose is reversed and is replaced by an unusually high deformation. The plastic deformation was studied of miniature flat tensile specimens of 12Cr18Ni10Ti austenitic steel cut from a fuel assembly wrapper irradiated in the BN-350 reactor to 55 dpa at 580 K (307 deg. C). A new optical extensometry technique was employed that uses a video camera and multiple tiny markers painted on the specimen, allowing visualization and recording of the strain distribution as it develops along the specimen. The total deformation derived from the engineering diagrams for these specimens was 35-40%, while 3-7% was expected from previous studies conducted at lower dpa levels. The video record showed that the material resists necking and involves a moving deformation wave that initiates near one of the tensile grippers and spreads along ∼3/4 of the gauge length before failure occurs. Such behavior, often called a 'moving neck' has been observed previously in pure iron and Al-Mg alloys but has not been observed in irradiated stainless steels

Physical mapping of the 5S and 18S rDNA in ten species of Hypostomus Lacépède 1803 (Siluriformes: Loricariidae): evolutionary tendencies in the genus.

Science.gov (United States)

Bueno, Vanessa; Venere, Paulo César; Thums Konerat, Jocicléia; Zawadzki, Cláudio Henrique; Vicari, Marcelo Ricardo; Margarido, Vladimir Pavan

2014-01-01

Hypostomus is a diverse group with unclear aspects regarding its biology, including the mechanisms that led to chromosome diversification within the group. Fluorescence in situ hybridization (FISH) with 5S and 18S rDNA probes was performed on ten Hypostomini species. Hypostomus faveolus, H. cochliodon, H. albopunctatus, H. aff. paulinus, and H. topavae had only one chromosome pair with 18S rDNA sites, while H. ancistroides, H. commersoni, H. hermanni, H. regani, and H. strigaticeps had multiple 18S rDNA sites. Regarding the 5S rDNA genes, H. ancistroides, H. regani, H. albopunctatus, H. aff. paulinus, and H. topavae had 5S rDNA sites on only one chromosome pair and H. faveolus, H. cochliodon, H. commersoni, H. hermanni, and H. strigaticeps had multiple 5S rDNA sites. Most species had 18S rDNA sites in the telomeric region of the chromosomes. All species but H. cochliodon had 5S rDNA in the centromeric/pericentromeric region of one metacentric pair. Obtained results are discussed based on existent phylogenies for the genus, with comments on possible dispersion mechanisms to justify the variability of the rDNA sites in Hypostomus.

Physical Mapping of the 5S and 18S rDNA in Ten Species of Hypostomus Lacépède 1803 (Siluriformes: Loricariidae: Evolutionary Tendencies in the Genus

Directory of Open Access Journals (Sweden)

Vanessa Bueno

2014-01-01

Full Text Available Hypostomus is a diverse group with unclear aspects regarding its biology, including the mechanisms that led to chromosome diversification within the group. Fluorescence in situ hybridization (FISH with 5S and 18S rDNA probes was performed on ten Hypostomini species. Hypostomus faveolus, H. cochliodon, H. albopunctatus, H. aff. paulinus, and H. topavae had only one chromosome pair with 18S rDNA sites, while H. ancistroides, H. commersoni, H. hermanni, H. regani, and H. strigaticeps had multiple 18S rDNA sites. Regarding the 5S rDNA genes, H. ancistroides, H. regani, H. albopunctatus, H. aff. paulinus, and H. topavae had 5S rDNA sites on only one chromosome pair and H. faveolus, H. cochliodon, H. commersoni, H. hermanni, and H. strigaticeps had multiple 5S rDNA sites. Most species had 18S rDNA sites in the telomeric region of the chromosomes. All species but H. cochliodon had 5S rDNA in the centromeric/pericentromeric region of one metacentric pair. Obtained results are discussed based on existent phylogenies for the genus, with comments on possible dispersion mechanisms to justify the variability of the rDNA sites in Hypostomus.

Steel Industry Marginal Opportunity Analysis

Energy Technology Data Exchange (ETDEWEB)

none,

2005-09-01

The Steel Industry Marginal Opportunity Analysis (PDF 347 KB) identifies opportunities for developing advanced technologies and estimates both the necessary funding and the potential payoff. This analysis determines what portion of the energy bandwidth can be captured through the adoption of state-of-the-art technology and practices. R&D opportunities for addressing the remainder of the bandwidth are characterized and plotted on a marginal opportunity curve.

The heat treatment effect on the structural changes and properties of high-nitrogen chromium steels

International Nuclear Information System (INIS)

Blinov, V.M.; Elistratov, A.A.; Kolesnikov, A.G.; Rakhshtadt, A.G.; Plokhikh, A.I.; Morozova, E.I.; Kostina, M.V.

2000-01-01

The structural transformations in the steels with 0.4-1.3 %N and 15-24 %Cr content, originating by thermal treatment, are studied. The dependences of the phase composition of the high-chromium steels (18 %Cr) on the nitrogen content are established. The ratio of the unchanged austenite increases and the martensite quantity decreases correspondingly with growth of the nitrogen concentration from 0.4 up to 1.2 %. The effect of strengthening the steels with the initial martensite structure as well as austenite and martensite steels is observed in the process of steels tempering due to the hardening on the account of the martensite dispersion hardening [ru

In vivo biodistribution of two [18F]-labelled muscarinic cholinergic receptor ligands: 2-[18F]- and 4-[18F]-fluorodexetimide

International Nuclear Information System (INIS)

Wilson, A.A.; Scheffel, U.A.; Dannals, R.F.; Stathis, M.; Ravert, H.T.; Wagner, H.N. Jr.

1991-01-01

Two [ 18 F]-labelled analogues of the potent muscarinic cholinergic receptor (m-AChR) antagonist, dexetimide, were evaluated as potential ligands for imaging m-AChR by positron emission tomography (PET). Intravenous administration of both 2-[ 18 F]- or 4-[ 18 F]-fluorodexetimide resulted in high brain uptake of radioactivity in mice. High binding levels were observed in m-AChR rich areas, such as cortex and striatum, with low levels in the receptor-poor cerebellum. Uptake of radioactivity was saturable and could be blocked by pre-administration of dexetimide or atropine. Drugs with different sites of action were ineffective at blocking receptor binding. The results indicate that both radiotracers are promising candidates for use in PET studies

Aging degradation of cast stainless steel

International Nuclear Information System (INIS)

Chopra, O.K.; Chung, H.M.

1986-10-01

A program is being conducted to investigate the significance of in-service embrittlement of cast duplex stainless steels under light-water reactor operating conditions. Microstructures of cast materials subjected to long-term aging either in reactor service or in the laboratory have been characterized by TEM, SANS, and APFIM techniques. Two precipitate phases, i.e., the Cr-rich α' and Ni- and Si-rich G phase, have been identified in the ferrite matrix of the aged steels. The results indicate that the low-temperature embrittlement is primarily caused by α' precipitates which form by spinodal decomposition. The relative contribution of G phase to loss of toughness is now known. Microstructural data also indicate that weakening of ferrite/austenite phase boundary by carbide precipitates has a significant effect on the onset and extent of embrittlement of the high-carbon CF-8 and CF-8M grades of stainless steels, particularly after aging at 400 or 450 0 C. Data from Charpy-impact, tensile, and J-R curve tests for several heats of cast stainless steel aged up to 10,000 h at 350, 400, and 450 0 C are presented and correlated with the microstructural results. Thermal aging of the steels results in an increase in tensile strength and a decrease in impact energy, J/sub IC/, and tearing modulus. The fracture toughness results show good agreement with the Charpy-impact data. The effects of compositional and metallurgical variables on loss of toughness are discussed

Parametrical limits of SCC-susceptibility of austenitic and austenitic-ferritic Cr-Ni steels

International Nuclear Information System (INIS)

Starosvetskij, D.I.; Baru, R.L.; Bondarenko, A.I.; Bogoyavlenskij, V.L.; Timonin, V.A.

1990-01-01

Comparative investigations into corrosion cracking (CC) of austenitic (12Kh18N10T) and austenitic-ferritic (08Kh22N6T) chromium-nickel steels are performed for various chloride media in a wide range of chloride concentrations and temperatures. It is shown that the ratio between steels in terms of their CC-susceptibility is not definite and can undergo a reversal depending on parameters of medium, level and conditions of loading. Differences in mechanisms of corrosion cracking of austenitic and austenitic-ferritic steels are established

Estimation of fracture toughness of cast stainless steels during thermal aging in LWR systems

International Nuclear Information System (INIS)

Chopra, O.K.

1991-06-01

A procedure and correlations are presented for predicting the change in fracture toughness of cast stainless steel components due to thermal aging during service in light water rectors (LWRs) at 280--330 degrees C (535--625 degrees F). The fracture toughness J-R curve and Charpy-impact energy of aged cast stainless steels are estimated from known mineral in formation. Fracture toughness of a specific cast stainless steel is estimated from the extent and kinetics of thermal embrittlement. The extent of thermal embrittlement is characterized by the room-temperature ''normalized'' Charpy-impact energy. A correlation for the extent of embrittlement at ''saturation,'' i.e., the minimum impact energy that would be achieved for the material after long-term aging, is given in terms of a material parameter, Φ, which is determined from the chemical composition. The fracture toughness J-R curve for the material is then obtained from correlations between room-temperature Charpy-impact energy and fracture toughness parameters. Fracture toughness as a function of time and temperature of reactor service is estimated from the kinetics of thermal embrittlement, which is determined from chemical composition. A common ''lower-bound'' J-R curve for cast stainless steels with unknown chemical composition is also defined for a given material specification, ferrite content, and temperature. Examples for estimating impact strength and fracture toughness of cast stainless steel components during reactor service are describes. 24 refs., 39 figs., 2 tabs

Estimation of fracture toughness of cast stainless steels during thermal aging in LWR systems

Energy Technology Data Exchange (ETDEWEB)

Chopra, O.K. (Argonne National Lab., IL (USA))

1991-06-01

A procedure and correlations are presented for predicting the change in fracture toughness of cast stainless steel components due to thermal aging during service in light water rectors (LWRs) at 280--330{degrees}C (535--625{degrees}F). The fracture toughness J-R curve and Charpy-impact energy of aged cast stainless steels are estimated from known mineral in formation. Fracture toughness of a specific cast stainless steel is estimated from the extent and kinetics of thermal embrittlement. The extent of thermal embrittlement is characterized by the room-temperature normalized'' Charpy-impact energy. A correlation for the extent of embrittlement at saturation,'' i.e., the minimum impact energy that would be achieved for the material after long-term aging, is given in terms of a material parameter, {Phi}, which is determined from the chemical composition. The fracture toughness J-R curve for the material is then obtained from correlations between room-temperature Charpy-impact energy and fracture toughness parameters. Fracture toughness as a function of time and temperature of reactor service is estimated from the kinetics of thermal embrittlement, which is determined from chemical composition. A common lower-bound'' J-R curve for cast stainless steels with unknown chemical composition is also defined for a given material specification, ferrite content, and temperature. Examples for estimating impact strength and fracture toughness of cast stainless steel components during reactor service are describes. 24 refs., 39 figs., 2 tabs.

On the Nature of Internal Interfaces in Tempered Martensite Ferritic Steels

Czech Academy of Sciences Publication Activity Database

Dronhofer, A.; Pešička, J.; Dlouhý, Antonín; Eggeler, G.

2003-01-01

Roč. 94, č. 5 (2003), s. 511-520 ISSN 0044-3093 R&D Projects: GA ČR GA106/99/1172 Institutional research plan: CEZ:AV0Z2041904 Keywords : Tempered martensite ferritic steels * martensite variants * orientation imaging Subject RIV: JG - Metallurgy Impact factor: 0.637, year: 2003

Morphology and 18S rDNA of Henneguya gurlei (Myxosporea) from Ameiurus nebulosus (Siluriformes) in North Carolina.

Science.gov (United States)

Iwanowicz, Luke R; Iwanowicz, Deborah D; Pote, Linda M; Blazer, Vicki S; Schill, William B

2008-02-01

Henneguya gurlei was isolated from Ameiurus nebulosus captured in North Carolina and redescribed using critical morphological features and 18S small-subunit ribosomal RNA (SSU rDNA) gene sequence. Plasmodia are white, spherical, or subspherical, occur in clusters, measure up to 1.8 mm in length, and are located on the dorsal, pectoral, and anal fins. Histologically, plasmodia are located in the dermis and subdermally, and the larger cysts disrupt the melanocyte pigment layer. The spore body is lanceolate, 18.2 +/- 0.3 microm (range 15.7-20.3) in length, and 5.4 +/- 0.1 microm (range 3.8-6.1) in width in valvular view. The caudal appendages are 41.1 +/- 1.1 microm (range 34.0-49.7) in length. Polar capsules are pyriform and of unequal size. The longer polar capsule measures 6.2 +/- 0.1 microm (range 5.48-7.06), while the shorter is 5.7 +/- 0.1 microm (range 4.8-6.4) in length. Polar capsule width is 1.2 +/- 0.03 microm (range 1.0-1.54). The total length of the spore is 60.9 +/- 1.2 microm (range 48.7-68.5). Morphologically, this species is similar to other species of Henneguya that are known to infect ictalurids. Based on SSU rDNA sequences, this species is most closely related to H. exilis and H. ictaluri, which infect Ictalurus punctatus.

High specific radioactivity (1R,2S)-4-[18F]fluorometaraminol: a PET radiotracer for mapping sympathetic nerves of the heart

International Nuclear Information System (INIS)

Langer, Oliver; Valette, Heric; Dolle, Frederic; Halldin, Christer; Loc'h, Christian; Fuseau, Chantal; Coulon, Christine; Ottaviani, Michele; Bottlaender, Michel; Maziere, Bernard; Crouzel, Christian

2000-01-01

The radiolabeled catecholamine analogue (1R,2S)-6-[ 18 F]fluorometaraminol (6-[ 18 F]FMR) is a substrate for the neuronal norepinephrine transporter. It has been used as a positron emission tomography (PET) ligand to map sympathetic nerves in dog heart. 6-[ 18 F]FMR could be only synthesized with low specific radioactivity, which precluded its use in human subjects. We have recently prepared (1R,2S)-4-[ 18 F]fluorometaraminol (4-[ 18 F]FMR), a new fluoro-analogue of metaraminol, with high specific radioactivity (56-106 GBq/μmol). In the present study, we demonstrate in rats that 4-[ 18 F]FMR possesses similar affinity toward myocardial norepinephrine transport mechanisms as 6-[ 18 F]FMR. When compared with control animals, an 80% and 76% reduction in myocardial uptake was observed in animals pretreated with desipramine (an inhibitor of the neuronal norepinephrine transporter) and with reserpine (a blocker of the vesicular storage of monoamines), respectively. The entire radioactivity in rat myocardium represented unmetabolized parent tracer as determined by high performance liquid chromatography analysis of tissue extracts. In dogs, myocardial kinetics of 4-[ 18 F]FMR were assessed using PET. A rapid and high uptake was observed, followed by prolonged cardiac retention. A heart-to-lung ratio of 15 was reached 10 min after injection of the radiotracer. Pretreatment with desipramine reduced the heart half-life of 4-[ 18 F]FMR by 90% compared with control. Moreover, an infusion of tyramine caused a rapid decline of radioactivity in the heart. This demonstrates that 4-[ 18 F]FMR specifically visualizes sympathetic neurons in dog heart. High specific radioactivity 4-[ 18 F]FMR is a promising alternative to 6-[ 18 F]FMR for myocardial neuronal mapping with PET in humans

Influence of structure and properties of tubular billets of the 12 Kh 18N10T steel on deformability of tubes at cold-rolling mills

International Nuclear Information System (INIS)

Vil'yams, O.S.; Bol'shova, N.M.; Olejnik, O.V.; Velikotnaya, E.S.

1979-01-01

Metallographic analysis of the defects of the ''oblique cracks'' type on the surface of hot-rolled tubes of the 12Kh18N10T steel has been carried out. Recommended is the complex of mechanical properties and the structure factors (grain size) of conversion hot-rolled tubes, providing the combination of ductility and high rapture strength during rolling at pilger mills. At a grain size not coarser than number 5, a billet must have σsub(T) 5 >=40 %. Hot-rolled coarse-grained billet is not recommended for warm rolng because of high strain hardening

Microstructure based modelling of ductile fracture in quench-hardenable boron steel

OpenAIRE

Östlund, Rickard

2015-01-01

Reduction of fuel consumption and emissions by vehicle weight minimization constitute a major driving force for the development of new materials and manufacturing processes in the automotive industry. Simultaneously formed and quenched boron steel components have higher strength to weight ratio than conventional mild steel components. Additionally, hot formed components can be tailored to have regions with lower strength and higher ductility, improving their crash performance. This is often r...

A Study of the Effect of Interrupted Quenches on a Thermomechanically Processed High Carbon Steel.

Science.gov (United States)

1982-10-01

steel . Successful martempering requires a cooling rate sufficient to avoid the nose of the C- curve and thus prevent significant bainite formation. When...STUDY OF THE EFFECT OF INTERRUPTED QUENCHES ON A THERMONECHANICALLY PROCESSED HIGH CARBON STEEL by Steven A. Barton October 1982 Thesis Advisor: T.R...unlimited. A Study of the Effect of Interrupted Quenches on a Thermomechanically Processed High Carbon Steel by Steven A. Barton Lieutenant, United

Reactor Pressure Vessel Steels

Energy Technology Data Exchange (ETDEWEB)

Van de Velde, J.; Fabry, A.; Van Walle, E.; Chaoudi, R

1998-07-01

SCK-CEN's R and D programme on Reactor Pressure Vessel (RPV) Steels in performed in support of the RVP integrity assessment. Its main objectives are: (1) to develop enhanced surveillance concepts by applying micromechanics and fracture-toughness tests to small specimens, and by performing damage modelling and microstructure characterization; (2) to demonstrate the applied methodology on a broad database; (3) to achieve regulatory acceptance and industrial use. Progress and achievements in 1999 are reported.

Nickel alloys and high-alloyed special stainless steels. Properties, manufacturing, applications. 4. compl. rev. ed.

International Nuclear Information System (INIS)

Heubner, Ulrich; Kloewer, Jutta; Alves, Helena; Behrens, Rainer; Schindler, Claudius; Wahl, Volker; Wolf, Martin

2012-01-01

This book contains the following eight topics: 1. Nickel alloys and high-alloy special stainless steels - Material overview and metallurgical principles (U. Heubner); 2. Corrosion resistance of nickel alloys and high-alloy special stainless steels (U. Heubner); 3. Welding of nickel alloys and high-alloy special stainless steels (T. Hoffmann, M. Wolf); 4. High-temperature materials for industrial plant construction (J. Kloewer); 5. Nickel alloys and high-alloy special stainless steels as hot roll clad composites-a cost-effective alternative (C. Schindler); 6. Selected examples of the use of nickel alloys and high-alloy special stainless steels in chemical plants (H. Alves); 7. The use of nickel alloys and stainless steels in environmental engineering (V. Wahl); 8: Nickel alloys and high-alloy special stainless steels for the oil and gas industry (R. Behrens).

Heterogeneity of structure and properties of 12Cr18Ni10Ti and 08Cr16Ni11Mo3 stainless steels irradiated up to high damaging doses in reactor Bn-350

International Nuclear Information System (INIS)

Maksimkin, O.P.; Tivanova, O.V.; Turubarova, L.G.; Silnyagina, N.S.; Doronina, T.A.

2006-01-01

Full text: Earlier, during investigation of post-operating properties and structure of responsible units of fast neutron reactors there was shown /1, 2/ that depending on character of preliminary treatment of austenite stainless steel (austenization, cold deformation, mechanical and thermal treatment) radiation effects could be different. In /2/ one could observe heterogeneity at swelling of cold- worked hexahedral ducts along perimeter, in particular, the swelling of corners was less than plates'. At the same time after mechanical-thermal treatment the corners swell in 3-5 times of magnitude higher than plates. By the present there are several assumptions about nature of this phenomenon. One of them is a difference of deformation degree of material in corners and plates of the duct. It is known that /3/ external effects (including deformation) induce martensitic γ→α transformation in austenitic steels, due to which the structure and properties of steel are changed. In particular, paramagnetic FCC matrix reveals sites with ferromagnetic BCC structure. Steel heating, containing martensitic α-phase higher than ∼ 450-800 deg C, results in reverse γ→α transformation in material, which in its turn leads to formation of phase phase-hardened austenite. We can expect that only peculiarities of processes of direct and reverse martensitic transformations, which took place during preliminary austenitic steel treatment, will predetermine its behavior under irradiation. Taking into account the above mentioned there have been carried out complex material-scientific investigations of 12Cr18Ni10Ti and 08Cr16Ni11Mo3 steel samples cut off from different sites (both adjacent to corners and far from them) of hexagonal ducts of spent fuel assemblies of BN-350 reactor. There were used samples in the form of plates of different sizes: 5x10x2 mm - for metallographic investigations (microscope Neophot-2) and determination of microhardness (PMT-3); 2x20x0,3 mm - for mechanical

Creep rupture behavior of 9Cr–1.8W–0.5Mo–VNb (ASME grade 92) ferritic steel weld joint

Energy Technology Data Exchange (ETDEWEB)

Sakthivel, T., E-mail: tsakthivel@igcar.gov.in; Vasudevan, M.; Laha, K., E-mail: laha@igcar.gov.in; Parameswaran, P.; Chandravathi, K.S.; Panneer Selvi, S.; Maduraimuthu, V.; Mathew, M.D.

2014-01-03

Creep rupture behavior of 9Cr–1.8W–0.5Mo–VNb (ASME grade 92) ferritic steel weld joint fabricated by activated TIG (A-TIG) welding process have been investigated at 923 K over a stress range of 80–150 MPa. The weld joint was comprise of fusion zone, heat affected zone (HAZ) and base metal. The HAZ consisted of coarse prior-austenite grain (CGHAZ), fine prior-austenite grain (FGHAZ) and intercritical (ICHAZ) regions in an order away from the fusion zone to base metal. A hardness trough was observed at the outer edge of HAZ of the weld joint. TEM investigation revealed the presence of coarse M{sub 23}C{sub 6} precipitates and recovery of martensite lath structure into subgrain in the ICHAZ of the weld joint, leading to the hardness trough. The weld joint exhibited lower creep rupture lives than the base metal at relatively lower stresses. Creep rupture failure location of the weld joint was found to shift with applied stress. At high stresses fracture occurred in the base metal, whereas failure location shifted to FGHAZ at lower stresses with significant decrease in rupture ductility. SEM investigation of the creep ruptured specimens revealed precipitation of Laves phase across the joint, more extensively in the FGHAZ. On creep exposure, the hardness trough was found to shift from the ICHAZ to FGHAZ. Extensive creep cavitation was observed in the FGHAZ and was accompanied with the Laves phase, leading to the premature type IV failure of the steel weld joint at the FGHAZ.

Crude Oil Corrosion Fatigue of L485MB Pipeline Steel

Czech Academy of Sciences Publication Activity Database

Gajdoš, Lubomír; Šperl, Martin; Bystrianský, J.

2015-01-01

Roč. 137, č. 5 (2015), 051401 ISSN 0094-9930 R&D Projects: GA TA ČR(CZ) TE02000162 Institutional support: RVO:68378297 Keywords : corrosion fatigue * crude oil * pipeline steel * S–N curve * separated water Subject RIV: JI - Composite Materials Impact factor: 0.476, year: 2015 http://pressurevesseltech.asmedigitalcollection.asme.org/article.aspx?articleID=2107675

1x2M steel performance in the BOR-60 steam generator

International Nuclear Information System (INIS)

Golovanov, V.N.; Shamardin, V.K.; Kondratiev, V.I.; Kryukov, F.N.; Chernobrovkin, Yu.V.; Bulanova, T.M.; Bai, V.F.

The results from studies of 1x2M steel characteristics are presented. This steel was used as the material for the BOR-60 steam generator that had been in operation under the steam generating mode for 18,000 hs (35,000 hs in sodium). It was revealed that the pit corrosion depth on the water/steam side evaporative tube surfaces was about 0.25 μm and less and the total corrosion rate was less than 0.06 mm/y. The mechanical properties of the material were essentially similar both in the evaporator and superheater and met all the requirements imposed on. Based on the analysis of data on the decarbonizaton depth in sodium and on the corrosion damage in water and steam it was concluded that 1x2M steel can be successfully used as the steam generator material at the operating temperatures up to 470 deg. C and had sufficiently longer service-life as compared to 18,000 hs. (author)

R and D progress of Korean HCSB TBM

Energy Technology Data Exchange (ETDEWEB)

Cho, Seungyon, E-mail: sycho@nfri.re.kr [National Fusion Research Institute, 169-148 Gwahangno, Yuseong-gu, Daejeon 305-806 (Korea, Republic of); Ahn, Mu-Young; Yu, In-Keun; Park, Yi-Hyun; Ku, Duck Young [National Fusion Research Institute, 169-148 Gwahangno, Yuseong-gu, Daejeon 305-806 (Korea, Republic of); Lee, Sang-Jin [Mokpo National University, 1666 Youngsan-ro, Cheonggye-myeon, Muan-gun, Jeonnam 534-729 (Korea, Republic of); Yoon, Han-Ki [Dong-Eui University, 995 Eomgwangno, Busan-jin-gu, Busan 614-714 (Korea, Republic of); Kim, Tae-Gyu [Pusan National University, 63-2 Busandaehangno,Geumjeong-gu, Busan 609-735 (Korea, Republic of)

2012-08-15

Several R and Ds are being performed for Korean helium cooled solid breeder (HCSB) test blanket module (TBM) in the field of hydrogen isotopes permeation characteristics measurement in the helium purge line, joining technologies of structural materials, breeder pebble materials development, and the measurement of pebble bed characteristics. Electron beam welding for reduced activated ferritic-martensitic (RAFM) steel is evaluated to find optimal welding conditions. Also, a hydrogen permeation measurement apparatus is newly installed for the evaluation of the permeation barrier characteristics of stainless steel and RAFM steels. Two fabrication methods of lithium orthosilicate pebbles are investigated using slurry droplet methods. As methods of silicon carbide coating on the graphite pebble, microwave coating and chemical vapor deposition coating are evaluated. Two apparatuses are established to assess the thermo-mechanical properties of graphite and breeder pebble beds. The current status of R and D activities on these areas is introduced and the main progresses are addressed in this paper.

Constraint Effects at Brittle Fracture Initiation in a Cast Ferritic Steel

Czech Academy of Sciences Publication Activity Database

Dlouhý, Ivo; Chlup, Zdeněk; Kozák, Vladislav

č. 71 (2004), s. 873-883 ISSN 0013-7944 R&D Projects: GA AV ČR IAA2041003 Institutional research plan: CEZ:AV0Z2041904 Keywords : Cast ferritic steel * transition behaviour * fracture toughness Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 1.299, year: 2004 www.sciencedirect.com

High strength oil palm shell concrete beams reinforced with steel fibres

Directory of Open Access Journals (Sweden)

S. Poh-Yap

2017-10-01

Full Text Available The utilization of lightweight oil palm shell to produce high strength lightweight sustainable material has led many researchers towards its commercialization as structural concrete. However, the low tensile strength of Oil Palm Shell Concrete (OPSC has hindered its development. This study aims to enhance the mechanical properties and flexural behaviours of OPSC by the addition of steel fibres of up to 3% by volume, to produce oil palm shell fibre-reinforced concrete (OPSFRC. The experimental results showed that the steel fibres significantly enhanced the mechanical properties of OPSFRC. The highest compressive strength, splitting tensile and flexural strengths of 55, 11.0 and 18.5 MPa, respectively, were achieved in the OPSFRC mix reinforced with 3% steel fibres. In addition, the flexural beam testing on OPSFRC beams with 3% steel fibres showed that the steel fibre reinforcement up to 3% produced notable increments in the moment capacity and crack resistance of OPSFRC beams, but accompanied by reduction in the ductility.

Effect of intercritical heat treatment on mechanical properties of reinforcing steel bars

International Nuclear Information System (INIS)

Abro, M.I.; Memon, R.A.; Soomro, I.A.; Aftab, U.

2017-01-01

Intercritical heat treatments attempts were made to enhance the mechanical properties of reinforcing steel bars milled from scrap metal. For this, two grades of steel bars were obtained from different steel mills and their mechanical properties that include hardness, ultimate tensile strength, and percent elongation before and after intercritical heat treatment were determined. Results indicated that 25.5 and 17.6%, improvements in UTS (Ultimate Tensile Strength) and 18.8 and 14.3% improvement in percent elongation in two grades of reinforcing steel samples containing 0.17 and 0.24% carbon respectively was achieved while heating at 750 degree C for 2h. Appreciable improvement in the mechanical properties was noted due to birth of sufficient quantity of martensite along with ferrite. (author)

Microbial-Influenced Corrosion of Corten Steel Compared with Carbon Steel and Stainless Steel in Oily Wastewater by Pseudomonas aeruginosa

Science.gov (United States)

Mansouri, Hamidreza; Alavi, Seyed Abolhasan; Fotovat, Meysam

2015-07-01

The microbial corrosion behavior of three important steels (carbon steel, stainless steel, and Corten steel) was investigated in semi petroleum medium. This work was done in modified nutrient broth (2 g nutrient broth in 1 L oily wastewater) in the presence of Pseudomonas aeruginosa and mixed culture (as a biotic media) and an abiotic medium for 2 weeks. The behavior of corrosion was analyzed by spectrophotometric and electrochemical methods and at the end was confirmed by scanning electron microscopy. The results show that the degree of corrosion of Corten steel in mixed culture, unlike carbon steel and stainless steel, is less than P. aeruginosa inoculated medium because some bacteria affect Corten steel less than other steels. According to the experiments, carbon steel had less resistance than Corten steel and stainless steel. Furthermore, biofilm inhibits separated particles of those steels to spread to the medium; in other words, particles get trapped between biofilm and steel.

Corrosion behavior of steels in liquid lead bismuth with low oxygen concentrations

Science.gov (United States)

Kurata, Yuji; Futakawa, Masatoshi; Saito, Shigeru

2008-02-01

Corrosion tests in pots were conducted to elucidate corrosion behavior of various steels in liquid lead-bismuth for 3000 h under the condition of an oxygen concentration of 5 × 10 -8 wt% at 450 °C and an oxygen concentration of 3 × 10 -9 wt% at 550 °C, respectively. Significant corrosion was not observed at 450 °C for ferritic/martensitic steels, F82H, Mod.9Cr-1Mo steel, 410SS, 430SS except 2.25Cr-1Mo steel. Pb-Bi penetration into steels and dissolution of elements into Pb-Bi were severe at 550 °C even for ferritic/martensitic steels. Typical dissolution attack occurred for pure iron both at 550 °C without surface Fe 3O 4 and at 450 °C with a thin Fe 3O 4 film. Ferritization due to dissolution of Ni and Cr, and Pb-Bi penetration were recognized for austenitic stainless steels, 316SS and 14Cr-16Ni-2Mo steel at both temperatures of 450 °C and 550 °C. The phenomena were mitigated for 18Cr-20Ni-5Si steel. In some cases oxide films could not be a corrosion barrier in liquid lead-bismuth.

Electromagnetic NDT to characterize usage properties of flat steel products

Energy Technology Data Exchange (ETDEWEB)

Altpeter, I.; Dobmann, G.; Szielasko, K., E-mail: iab.altlau@t-online.de, E-mail: gerd.dobmann@t-online.de, E-mail: klaus.szielasko@izfp.fraunhofer.de [Fraunhofer Inst. - IZFP, Saarbruecken (Germany)

2015-07-15

The Fraunhofer Institute for Non-destructive Testing (IZFP) in Saarbruecken, Germany, started its activities in materials characterization of flat steel products in the eighties of the last century in the basic program of the European Community of Coal and Steel (ECCS). Throughout the years, continuous research and development were performed. The objective of the work, presented within this three-part series of reports, is to discuss the history of an innovation which began in 1988 with R&D in the area of texture characterization in steel sheets produced for car-body manufacturing (Part 1). In the following years the activities were to automate online property determination in terms of yield strength, tensile strength, planar, and vertical-anisotropy-factors. Again, steel sheets were the focus of the developments and the first NDT systems that came into industrial application for this project. Parallel research was performed to characterize the mechanical properties and hardness of heavy steel plates, mainly produced for pipeline manufacturing and off-shore applications (Part 2) The final report in the series (Part 3) will discuss steel sheet characterization and presents the successful development of a combination-transducer which combines ultrasonics with electromagnetic NDT. (author)

Electromagnetic NDT to characterize usage properties of flat steel products

International Nuclear Information System (INIS)

Altpeter, I.; Dobmann, G.; Szielasko, K.

2015-01-01

The Fraunhofer Institute for Non-destructive Testing (IZFP) in Saarbruecken, Germany, started its activities in materials characterization of flat steel products in the eighties of the last century in the basic program of the European Community of Coal and Steel (ECCS). Throughout the years, continuous research and development were performed. The objective of the work, presented within this three-part series of reports, is to discuss the history of an innovation which began in 1988 with R&D in the area of texture characterization in steel sheets produced for car-body manufacturing (Part 1). In the following years the activities were to automate online property determination in terms of yield strength, tensile strength, planar, and vertical-anisotropy-factors. Again, steel sheets were the focus of the developments and the first NDT systems that came into industrial application for this project. Parallel research was performed to characterize the mechanical properties and hardness of heavy steel plates, mainly produced for pipeline manufacturing and off-shore applications (Part 2) The final report in the series (Part 3) will discuss steel sheet characterization and presents the successful development of a combination-transducer which combines ultrasonics with electromagnetic NDT. (author)

Synthesis of new PET radiotracer 18F-Fluoro Ethyl Losartan for molecular imaging of AT1R in tumor model

International Nuclear Information System (INIS)

Ortega Pijeira, Martha Sahylí; Rodríguez Riera, Zalua; Pérez Nario, Arian; Soares Bernardes, Emerson; Gonçalves Nunes, Paulo; Sérgio Ivone Carvalho; Chammas, Roger; Elsinga, Philip

2016-01-01

Losartan is an antagonist of type 1 angiotensin II receptor (AT1R) and a drug widely used for the treatment of hypertension. Several studies have shown that losartan derivatives radiolabelled beta and gamma detect and quantify the expression of AT1R in some organs such as the heart and kidneys through the use of molecular imaging techniques. Furthermore, an expression of the AT1 receptor has been described in various types of tumors and correlates with an increased proliferation index and angiogenesis. Several groups have confirmed the antitumor effect of losartan potential, for example, in reducing tumor growth of a subtype of breast cancer. In this paper the synthesis of new radiotracer 18 F-fluoroethyl Losartan, and its standard compound is described. The standard compound was synthesized via fluoroethyl losartan reaction between losartan and fluoroethyl tosylate potassium in dimethylformamide at 80 ° C for 2 hours under argon. The base used in the reaction was sodium hydride. a complex mixture of products including the desired product fluoroethyl losartan with 14% yield was obtained. This compound was analyzed by HPLC and characterized by widely different spectroscopic techniques: 1H NMR, 13C NMR, 19F NMR, HSQC, HMBC and mass spectroscopy. 18 F synthesis losartan-fluoroethyl by indirect labeling of losartan potassium with 18 F-fluoroethyl prosthetic group tosylate to 80°C for 20 min under nitrogen is achieved manually, using hydrate of sodium as base. The compound was purified by preparative HPLC semi-(Acetonitrile (A) / agua 0 ,1% TFA (B), 60-80% A for 30 min, 4 mL / min, tR 8.9 min) and was obtained in 8 -21% (n = 5) and higher yield 99% radiochemical purity. The product identity was confirmed by comparison of residence times of the labeled product and the standard compound, HPLC analysis obtained under the same conditions: Acetonitrile (A) / agua 0 ,1% TFA (B), 55:45 A / B , 1 mL / min, tR 9.6 min. The 18 F-labeled prosthetic group fluoroethyl tosylate was

The effect of cyclic and dynamic loads on carbon steel pipe

International Nuclear Information System (INIS)

Rudland, D.L.; Scott, P.M.; Wilkowski, G.M.

1996-02-01

This report presents the results of four 152-mm (6-inch) diameter, unpressurized, circumferential through-wall-cracked, dynamic pipe experiments fabricated from STS410 carbon steel pipe manufactured in Japan. For three of these experiments, the through-wall crack was in the base metal. The displacement histories applied to these experiments were a quasi-static monotonic, dynamic monotonic, and dynamic, cyclic (R = -1) history. The through-wall crack for the third experiment was in a tungsten-inert-gas weld, fabricated in Japan, joining two lengths of STS410 pipe. The displacement history for this experiment was the same history applied to the dynamic, cyclic base metal experiment. The test temperature for each experiment was 300 C (572 F). The objective of these experiments was to compare a Japanese carbon steel pipe material with US pipe material, to ascertain whether this Japanese steel was as sensitive to dynamic and cyclic effects as US carbon steel pipe. In support of these pipe experiments, quasi-static and dynamic, tensile and fracture toughness tests were conducted. An analysis effort was performed that involved comparing experimental crack initiation and maximum moments with predictions based on available fracture prediction models, and calculating J-R curves for the pipe experiments using the η-factor method

Effect of prestress on performance of a 1.8 m SSC R ampersand D dipole

International Nuclear Information System (INIS)

Wanderer, P.; Anerella, M.; Cottingham, G.; Ganetis, G.; Garber, M.; Ghosh, A.; Greene, A.; Gupta, R.; Herrera, J.; Kahn, S.; Kelly, E.; Meade, A.; Morgan, G.; Muratore, J.; Prodell, A.; Rehak, M.; Rohrer, E.; Sampson, W.; Shutt, R.; Thompson, P.; Willen, E.; Goodzeit, C.

1991-01-01

A series of 1.8 SSC dipoles is being built and tested as part of the R ampersand D program. One of the 40 mm - aperture magnets was tested with a standard assembly and then reassembled and retested in a special configuration which had significantly less azimuthal prestress than the initial assembly. We report quench, coil stress, end force, and harmonics data for each of the assemblies. Quench performance was not degraded for the low-prestress assembly. 4 refs., 5 figs., 5 tabs

Reaction of uranium and plutonium carbides with austenitic steels; Reaction des carbures d'uranium et de plutonium avec des aciers austenitiques

Energy Technology Data Exchange (ETDEWEB)

Mouchnino, M [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1967-07-01

The reaction of uranium and plutonium carbides with austenitic steels has been studied between 650 and 1050 deg. C using UC, steel and (UPu)C, steel diffusion couples. The steels are of the type CN 18.10 with or without addition of molybdenum. The carbides used are hyper-stoichiometric. Tests were also carried out with UCTi, UCMo, UPuCTi and UPuCMo. Up to 800 deg. C no marked diffusion of carbon into stainless steel is observed. Between 800 and 900 deg. C the carbon produced by the decomposition of the higher carbides diffuses into the steel. Above 900 deg. C, decomposition of the monocarbide occurs according to a reaction which can be written schematically as: (U,PuC) + (Fe,Ni,Cr) {yields} (U,Pu) Fe{sub 2} + Cr{sub 23}C{sub 6}. Above 950 deg. C the behaviour of UPuCMo and that of the titanium (CN 18.12) and nickel (NC 38. 18) steels is observed to be very satisfactory. (author) [French] La reaction des carbures d'uranium et de plutonium avec des aciers austenitiques a ete etudiee entre 650 deg. C et 1050 deg. C a partir de couples de diffusion UC, acier et (UPu)C, acier. Les aciers sont du type CN 18.10 avec ou sans addition de molybdene. Les carbures utilises sont hyper-stoechiometriques. En outre on a fait des essais avec UCTi, UCMo, UPuCTi, UPuCMo. Jusqu'a 800 deg. C on ne detecte pas de diffusion sensible du carbone dans l'acier inoxydable. Entre 800 et 900 deg. C il y a diffusion dans l'acier du carbone provenant de la decomposition des carbures superieurs. A partir de 900 deg. C il y a decomposition du monocarbure selon une reaction que l'on ecrit schematiquement: (U,PuC) + (Fe, Ni, Cr) {yields} (U,Pu)Fe{sub 2} + Cr{sub 23}C{sub 6}. Nous notons a 950 deg. C le bon comportement de UPuCMo ainsi que celui des aciers au titane (CN 18. 12) et au nickel (NC 38.18). (auteur)

Theoretical description of the influence of neutron irradiation on viscoplastic properties of mild steel

International Nuclear Information System (INIS)

Pecherski, R.

1978-01-01

The physical bases of plastic deformation of mild steel are described. The influence of neutron irradiation on the change of mechanisms of plastic deformation is discussed in detail. Constitutive equations of viscoplasticity for irradiated mild steel are given. The problem of thickwalled viscoplastic spherical tank irradiated by neutrons is studied. (Z.R.)

Fracture of Fe--Cr--Mn austenitic steel

International Nuclear Information System (INIS)

Caskey, G.R. Jr.

1979-01-01

Tensile tests of Tenelon (U.S. Steel), a nitrogen-strengthened iron-base alloy containing 18% chromium and 15% manganese, demonsterated that cleavage fracture can occur in some austenitic steels and is promoted by the presence of hydrogen. Tensile failure of Tenelon at 78 0 K occurred with no detectable necking at low strain levels. The fracture surface contained cleavage facets that lay along coherent twin boundaries oriented transversely to the tensile axis. Charging gaseous hydrogen at 679 MPa pressure and 650 0 K had no significant effect on the mechanical behavior or fracture mode at 78 0 K, but raised the ductile-to-brittle transition temperature from less than 200 0 K to about 250 0 K

Aircraft Steels

Science.gov (United States)

2009-02-19

component usage. PH 13-8Mo is a precipitation-hardenable martensitic stainless steel combining excellent corrosion resistance with strength. Custom 465 is...a martensitic , age-hardenable stainless steel capable of about 1,724 MPa (250 ksi) UTS when peak-aged (H900 condition). Especially, this steel can...NOTES 14. ABSTRACT Five high strength steels (4340, 300M, AerMet 100, Ferrium S53, and Hy-Tuf) and four stainless steels (High Nitrogen, 13

Kinetics of manganese in MAG/MIG welding with a 18/8/6 wire

International Nuclear Information System (INIS)

Tusek, J.

2001-01-01

The paper deals with a study of MAG/MIG welding of low-alloy ferritic steel and high-alloy austenitic steel with a 18/8/6 wire. Manganese burn-off from the wire in welding a single-V butt weld was studied. It was found that manganese burns off in the arc during melting of a droplet at the wire end, and from the weld pool during weld formation. The range of manganese burn-of-depends mainly on the type of shielding gas used and the arc length,i. e., from the arc voltage. The manganese burn-off increases with an increase of the content of active gases, i.e., CO 2 and O 2 in the neutral gas i. e., argon. It also increases with an increase in arc voltage. The longer the welding arc, the longer exposition of the filler materials to the welding arc and the wider the penetration, Which allows manganese vapours to evaporate from the weld pool. The most important finding is that manganese burn-off from the 18/8/6 wire during welding of austenitic stainless steel with low-alloy ferritic steel is considerably strong, i.e., from 20% to 30%; nevertheless the wire concerned is perfectly suitable for welding of different types of steel. (Author) 23 refs

Steel making

CERN Document Server

Chakrabarti, A K

2014-01-01

"Steel Making" is designed to give students a strong grounding in the theory and state-of-the-art practice of production of steels. This book is primarily focused to meet the needs of undergraduate metallurgical students and candidates for associate membership examinations of professional bodies (AMIIM, AMIE). Besides, for all engineering professionals working in steel plants who need to understand the basic principles of steel making, the text provides a sound introduction to the subject.Beginning with a brief introduction to the historical perspective and current status of steel making together with the reasons for obsolescence of Bessemer converter and open hearth processes, the book moves on to: elaborate the physiochemical principles involved in steel making; explain the operational principles and practices of the modern processes of primary steel making (LD converter, Q-BOP process, and electric furnace process); provide a summary of the developments in secondary refining of steels; discuss principles a...

Irradiation Effects in Fortiweld Steel Containing Different Boron Isotopes

International Nuclear Information System (INIS)

Grounes, M.

1967-07-01

Tensile specimens and miniature impact specimens of the low alloyed pressure vessel steel Fortiweld have been irradiated at 265 deg C in R2 to two neutron doses, 6.5 x 10 18 n/cm 2 (> 1 MeV) and 4 x 10 19 n/cm 2 (thermal) and also 9.0 x 10 18 n/cm 2 (> 1 MeV) and 6 x 10 19 n/cm 2 (thermal). Material from three laboratory melts, in which the boron consisted of 10 B, 11 B and natural boron respectively, were investigated. The results both of tensile tests and impact tests with miniature impact specimens show that the 10 B-alloyed material was changed more and the 11 B-alloyed material was changed less than the material containing natural boron. At the higher neutron dose the increase in yield strength (0.2 % offset yield strength) was 11 kg/mm in the 10 B containing material compared to 5 kg/mm in the 11 B-containing material. The decrease in total elongation was 5 and 0 percentage units respectively. The transition temperature was increased 190 deg C at the higher neutron dose in the 10 B-alloyed material, 40 deg C in the 11 B-alloyed material and 80 deg C in the material containing natural boron

75 FR 68970 - Amendment of Using Agency for Restricted Areas R-4002, R-4005, R-4006 and R-4007; MD

Science.gov (United States)

2010-11-10

...-1070; Airspace Docket No. 10-AEA-18] RIN 2120-AA66 Amendment of Using Agency for Restricted Areas R-4002, R-4005, R- 4006 and R-4007; MD AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: This action makes a minor change to the name of the using agency for restricted areas R...

Compatibility of manufacturing process fluids with R-134a and polyolester lubricant. Final report

Energy Technology Data Exchange (ETDEWEB)

Cavestri, R.C.; Schooley, D.L. [Imagination Resources, Inc., Dublin, OH (United States)

1996-07-01

This report includes a broad list of processing fluids that are known to be used to manufacture air conditioning and refrigeration products. Sixty-four process fluids from this list were selected for compatibility studies with R-134a and ICI EMKARATE RL32H (32 ISO) polyolester lubricant. Solutions or suspensions of the process fluid residues in polyolester lubricant were heated for 14 days at 175{degrees}C (347{degrees}F) in evacuated sealed glass tubes containing only valve steel coupons. Miscibility tests were performed at 90 wt.% R-134a, 10 wt.% polyolester lubricant with process fluid residue contaminate and were scanned in 10{degrees}C (18{degrees}F) increments over a temperature range of ambient to -40{degrees}C (-40{degrees}F). Any sign of turbidity, haze formation or oil separation was considered the immiscibility point.

Stainless steel corrosion in conditions simulating WWER-1000 primary coolant. Corrosion behaviour in mixed core

International Nuclear Information System (INIS)

Krasnorutskij, V.S.; Petel'guzov, I.A.; Gritsina, V.M.; Zuek, V.A.; Tret'yakov, M.V.; Rud', R.A.; Svichkar', N.V.; Slabospitskaya, E.A.; Ishchenko, N.I.

2011-01-01

Research into corrosion kinetics of austenitic stainless steels (06Cr18Ni10Ti, 08Cr18Ni10Ti, 12Cr18Ni10Ti) in medium which corresponds to composition and parameters of WWER-1000 primary coolant with different pH values in autoclave out-pile conditions during 14000 hours is given. Surface of oxide films on stainless steels is investigated. Visual inspection of Westinghouse and TVEL fuel was carried out after 4 cycles in WWER-1000 primary water chemistry conditions at South Ukraine NPP. Westinghouse and TVEL fuel cladding materials possess high corrosion resistance. Blushing of weldments was observed. No visual corrosion defects or deposits were observed on fuel rods.

Comments on the A. Aurengo document entitled 'the 2003 I.R.S.N. model of Chernobylsk accident fallout in France' - 18 december 2005

International Nuclear Information System (INIS)

2006-01-01

The present document brings the principal comments of I.R.S.N. on the analysis note of the 18. december 2005 treating the 2003 I.R.S.N. model on the Chernobylsk accident fallout in France, transmitted by Mister A. Aurengo. (N.C.)

Deformation and fracture behavior of the P91 martensitic steel at high temperatures

Czech Academy of Sciences Publication Activity Database

Šiška, Filip; Stratil, Luděk; Šmíd, Miroslav; Luptáková, Natália; Záležák, Tomáš; Bártková, Denisa

2016-01-01

Roč. 672, AUG (2016), s. 1-6 ISSN 0921-5093 R&D Projects: GA ČR GJ15-21292Y Institutional support: RVO:68081723 Keywords : Steel * Plastic ity * Stress relaxation * Dislocations Subject RIV: JG - Metallurgy Impact factor: 3.094, year: 2016

Cyclic plastic response and fatigue life of duplex and superduplex stainless steel

Czech Academy of Sciences Publication Activity Database

Polák, Jaroslav

43 2005, č. 4 (2005), s. 280-289 ISSN 0023-432X R&D Projects: GA ČR(CZ) GA106/02/0584 Institutional research plan: CEZ:AV0Z20410507 Keywords : duplex steel * fatigue life * cyclic plasticity Subject RIV: JG - Metallurgy Impact factor: 0.973, year: 2005

The crevice corrosion behaviour of stainless steel in sodium chloride solution

International Nuclear Information System (INIS)

Hu Qian; Zhang Guoan; Qiu Yubin; Guo Xingpeng

2011-01-01

Highlights: → There are three stages in crevice corrosion of 13Cr stainless steel in NaCl solution. → The decrease of crevice thickness shortens the incubation period of crevice corrosion. → The incubation period of crevice corrosion prolongs as the increase of the area ratio. → Corrosion develops preferentially at crevice bottom and hydrogen reduction occurs inside the crevice. → Crevice corrosion of 13Cr stainless steel in NaCl solution follows the passive dissolution mechanism. - Abstract: The crevice corrosion behaviour of 13Cr stainless steel in NaCl solution was investigated mainly by electrochemical noise measurements, considering the influences of the crevice opening dimension (a) and the area ratio of the electrode outside the crevice to the one inside the crevice (r). Results show that the increase of r value prolongs the incubation period of crevice corrosion, but crevice corrosion develops rapidly once the crevice corrosion occurs. The crevice corrosion develops preferentially at the crevice bottom and then spreads to the whole electrode surface. Proton could reduce on the uncorroded area and hydrogen bubbles form inside the crevice.

Thermal stress estimation in relation to spalling of HSC restrained with steel rings at high temperatures

Directory of Open Access Journals (Sweden)

Tanibe T.

2013-09-01

Full Text Available This paper reports on an experimental study regarding the behavior of steel ring-restrained concrete in response to fire exposure. The study was conducted to enable estimation of thermal stress based on steel ring strain in such concrete under the conditions of a RABT 30 heating curve. The specimens used were made from high-strength concrete (Fc: 80 MPa restrained using steel rings with thicknesses of 0.5, 8 and 18 mm.

Moisture-Dependent Physical Properties of Àbèèrè (Picralima nitida Seeds

Directory of Open Access Journals (Sweden)

A. K. Aremu

2015-08-01

Full Text Available Some relevant engineering properties of Àbèèrè (Picralima nitida seeds are needed for the design of its processing equipments. The geometric, gravimetric and frictional properties of Àbèèrè seed in the moisture content ranges of 7.98% - 47.77% (wb were investigated. The average length, width, thickness, arithmetic and geometric mean diameters, sphericity, surface area, volume, true and bulk densities and angles of repose increased from 28.76 – 30.75mm, 16.18 – 19.62mm, 5.75 – 7.15mm, 16.90 – 19.17mm, 13.81 – 16.11mm,0.48 – 0.53, 600.94 – 817.83mm2, 443.00 – 717.92mm3, 2.49×10-3 – 2.60×10-3g/mm3, 1.14×10-3 – 1.50×10-3g/mm3and 27.97o – 30.26o respectively as the moisture content increased from 7.98% to 47.77%. However, values for porosity decreased from 0.54 – 0.42. The static coefficient of friction of Àbèèrè increased linearly over the three material surfaces – plywood, stainless steel and glass – with increasing moisture content from 0.445 – 0.468, 0.286 – 0.384 and 0.357 – 0.389 respectively. The steel surface had the lowest static coefficient of friction whereas the plywood gave the highest value at all moisture content levels. The regression models developed for all the physical properties of the seeds had high coefficient of determination, R2.

Characterizing of steel used in the construction of civil works in Almeria

International Nuclear Information System (INIS)

Senobua, A. J.; Garzon, E.; Ayuso, J.; Perez, F.; Caballero, A.

2003-01-01

Various tests have been conducted on the steel bars used in the construction of civil works in Almeria (Spain) during the period 18 January 2000-7May 2001, with the aim of mechanically characterizing the different types of steel (weldable; B400S, B500S and ductile weldable: B400SD) to determine whether there is a technical reason for the increase in the use of ductile weldable steel. For this, we have used a hydraulic machine to break by traction all the test samples that arrived to the laboratory, following the specifications of the UNE 7474-1:1992 and the UNE 7474-2:1992. The results indicate that only in 86% of the cases does the steel B400SD satisfy the limits specified by the UNE 36065:1999-EX, as opposed to 95 and 94% of the B400S and B500S steels. In addition the ductile weldable steel registered mean values lower than those of B400S. This findings disagrees with expectations set by the specifications. (Author) 6 refs

High specific radioactivity (1R,2S)-4-[{sup 18}F]fluorometaraminol: a PET radiotracer for mapping sympathetic nerves of the heart

Energy Technology Data Exchange (ETDEWEB)

Langer, Oliver; Valette, Heric; Dolle, Frederic E-mail: dolle@dsvidf.cea.fr; Halldin, Christer; Loc' h, Christian; Fuseau, Chantal; Coulon, Christine; Ottaviani, Michele; Bottlaender, Michel; Maziere, Bernard; Crouzel, Christian

2000-04-01

The radiolabeled catecholamine analogue (1R,2S)-6-[{sup 18}F]fluorometaraminol (6-[{sup 18}F]FMR) is a substrate for the neuronal norepinephrine transporter. It has been used as a positron emission tomography (PET) ligand to map sympathetic nerves in dog heart. 6-[{sup 18}F]FMR could be only synthesized with low specific radioactivity, which precluded its use in human subjects. We have recently prepared (1R,2S)-4-[{sup 18}F]fluorometaraminol (4-[{sup 18}F]FMR), a new fluoro-analogue of metaraminol, with high specific radioactivity (56-106 GBq/{mu}mol). In the present study, we demonstrate in rats that 4-[{sup 18}F]FMR possesses similar affinity toward myocardial norepinephrine transport mechanisms as 6-[{sup 18}F]FMR. When compared with control animals, an 80% and 76% reduction in myocardial uptake was observed in animals pretreated with desipramine (an inhibitor of the neuronal norepinephrine transporter) and with reserpine (a blocker of the vesicular storage of monoamines), respectively. The entire radioactivity in rat myocardium represented unmetabolized parent tracer as determined by high performance liquid chromatography analysis of tissue extracts. In dogs, myocardial kinetics of 4-[{sup 18}F]FMR were assessed using PET. A rapid and high uptake was observed, followed by prolonged cardiac retention. A heart-to-lung ratio of 15 was reached 10 min after injection of the radiotracer. Pretreatment with desipramine reduced the heart half-life of 4-[{sup 18}F]FMR by 90% compared with control. Moreover, an infusion of tyramine caused a rapid decline of radioactivity in the heart. This demonstrates that 4-[{sup 18}F]FMR specifically visualizes sympathetic neurons in dog heart. High specific radioactivity 4-[{sup 18}F]FMR is a promising alternative to 6-[{sup 18}F]FMR for myocardial neuronal mapping with PET in humans.

Effect of temperature and heat fluxes on the corrosion's damage nature for mild and stainless steels in neutral chloride solutions

Energy Technology Data Exchange (ETDEWEB)

Kaluzhina, S.A. [Voronezh State University, University Sq.1, 394006 Voronezh (Russian Federation); Malygin, A.V. [JSC Voronezhsynthezkauchuk, Leninsky Av. 2, 394014 Voronezh (Russian Federation); Vigdorovitch, V.V. [Derzhavin State University, International St. 33, 392622 Tambov (Russian Federation)

2004-07-01

The detail research of the corrosion-electrochemical behavior of two types steels - mild steel (0.1%C) and stainless steel 12FeCr18Ni10Ti in series chloride solutions under elevated temperature and heat flux on interface has been carried out in the present work using the special plant and the complex electrochemical and microscopic methods. The comparative data has shown that the temperature increase is stimulating as the active alloy's corrosion (mild steel), so the passive alloy's corrosion (12FeCr18Ni10Ti).However at the last case the temperature effect is being higher because the thermal de-passivation of the stainless steel which undergoes pit corrosion under t > 50 deg C. The heat-transfer role in the studied systems is ambiguous. The corrosion rate of heat-transferring electrode from mild steel exceeds the thermo-equilibrium with solution electrode's corrosion rate because of intensification of the oxygen reduction cathodic process. The opposite effect has been established for steel 12FeCr18Ni10Ti where the oxygen flux's strengthening from cold solution to the heated surface transfers the alloy to the most stable passive state and increases its resistance to general and local corrosion. The experimental results demonstrates that the thermal condition's influence on the nature and corrosion intensity of the investigated steels is being commensurable by effect's degree with their composition and showing strictly individually. (authors)

Behaviour of ODS Steels in Cyclic Loading

Czech Academy of Sciences Publication Activity Database

Kuběna, Ivo; Kruml, Tomáš; Polák, Jaroslav

2016-01-01

Roč. 69, č. 2 (2016), s. 309-313 ISSN 0972-2815. [International Conference on CREEP , FATIGUE and CREEP -FATIGUE INTERACTION /7./. Kalpakkam, 19.01.2016-22.01.2016] R&D Projects: GA MŠk(CZ) ED1.1.00/02.0068; GA ČR GA15-08826S Institutional support: RVO:68081723 Keywords : ODS steels * low cycle fatigue * small fatigue crack * microstructure Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 0.533, year: 2016 http://link.springer.com/article/10.1007/s12666-015-0814-3

Comparison of magnetic nondestructive methods applied for inspection of steel degradation

Czech Academy of Sciences Publication Activity Database

Takahashi, S.; Kobayashi, S.; Tomáš, Ivan; Dupre, L.; Vértesy, G.

2017-01-01

Roč. 91, Jun (2017), s. 54-60 ISSN 0963-8695 R&D Projects: GA ČR GB14-36566G Institutional support: RVO:68378271 Keywords : magnetic hysteresis * magnetic NDT * steel degradation Subject RIV: BM - Solid Matter Physics ; Magnetism OBOR OECD: Condensed matter physics (including formerly solid state physics, supercond.) Impact factor: 2.726, year: 2016

Spatial structure determination of (√3 x √3)R30 degrees and (1.5 x 1.5)R18 degrees CO on Cu(111) using angle-resolved photoemission extended fine structure

International Nuclear Information System (INIS)

Moler, E.J.; Kellar, S.A.; Huff, W.R.A.

1997-01-01

The authors report a study of the spatial structure of (√3 x √3)R30 degrees (low coverage) and (1.5 x 1.5)R18 degrees (intermediate coverage) CO adsorbed on Cu(111), using the Angle-Resolved Photoemission Extended Fine Structure (ARPEFS) technique at beamline 9.3.2 at the Advanced Light Source. The CO molecule adsorbs on an atop site for both adsorption phases. Full multiple-scattering spherical-wave (MSSW) calculations were used to extract the C-Cu. bond length and the first Cu-Cu layer spacing for each adsorption phase. The authors find that the C-Cu bond length remains unchanged with increasing coverage, but the 1st Cu-Cu layer spacing contracts at the intermediate coverage. They calculate the bending mode force constant in the (1.5 x 1.5)R18 degrees phase to be K δ = 2.2 (1) x 10 -12 dyne-cm/rad from their experimentally determined bond lengths combined with previously published infra-red absorption frequencies

Long-term aging of cast stainless steels: Mechanisms and resulting properties

International Nuclear Information System (INIS)

Chopra, O.K.; Chung, H.M.

1988-01-01

Mechanical property data are presented from Charpy-impact, tensile, and J-R curve tests for several heats of cast stainless steel aged up to 10,000 h at 450, 400, 350, 320 and 290 deg. C. The results indicate that thermal aging increases the tensile strength and decreases the impact energy, J IC , and tearing modules of the steels. Also, the ductile-to-brittle transition curve shifts to higher temperatures. The ferrite content and concentration of carbon in the steel have a strong effect on the overall process of low-temperature embrittlement. The low-carbon CF-3 steels are the most resistant and the molybdenum-containing high-carbon CF-8M steels are the most susceptible to low-temperature embrittlement. Microstructural data indicate that three processes contribute to embrittlement of cast stainless steels, viz., Cr-rich α' and G-phase precipitation in the ferrite, and carbide precipitation on the austenite/ferrite phase boundary. The influence of nitrogen content and ferrite distribution on loss of toughness are discussed. The data also indicate that existing correlations do not accurately represent the embrittlement behavior over the temperature range 280-450 deg. C, i.e., extrapolation of high temperature data to reactor temperatures may not be valid for some compositions of cast stainless steel. (author)

Karyotypes, heterochromatin, and physical mapping of 18S-26S rDNA in Cactaceae.

Science.gov (United States)

Las Peñas, M L; Urdampilleta, J D; Bernardello, G; Forni-Martins, E R

2009-01-01

Karyotype analyses in members of the four Cactaceae subfamilies were performed. Numbers and karyotype formula obtained were: Pereskioideae = Pereskiaaculeata(2n = 22; 10 m + 1 sm), Maihuenioideae = Maihuenia patagonica (2n = 22, 9 m + 2 sm; 2n = 44, 18 m + 4 sm), Opuntioideae = Cumulopuntia recurvata(2n = 44; 20 m + 2 sm), Cactoideae = Acanthocalycium spiniflorum (2n = 22; 10 m + 1 sm),Echinopsis tubiflora (2n = 22; 10 m + 1 sm), Trichocereus candicans (2n = 22, 22 m). Chromosomes were small, the average chromosome length was 2.3 mum. Diploid species and the tetraploid C. recurvata had one terminal satellite, whereas the remaining tetraploid species showed four satellited chromosomes. Karyotypes were symmetrical. No CMA(-)/DAPI(+) bands were detected, but CMA(+)/DAPI(-) bands associated with NOR were always found. Pericentromeric heterochromatin was found in C. recurvata, A. spiniflorum, and the tetraploid cytotype of M. patagonica. The locations of the 18S-26S rDNA sites in all species coincided with CMA(+)/DAPI(-) bands; the same occurred with the sizes and numbers of signals for each species. This technique was applied for the first time in metaphase chromosomes in cacti. NOR-bearing pair no.1 may be homeologous in all species examined. In Cactaceae, the 18S-26S loci seem to be highly conserved. Copyright 2009 S. Karger AG, Basel.

Ulteriori osservazioni sul significato di parbār (1CR 26,18b alla luce di alcune versioni arabe

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Giancarlo Toloni

2018-06-01

Full Text Available In Modern Arabic Versions (editions of Beyruth and Cambridge of 1Chr 26:18, the word parbār is translated by the substantiv riwâqun / rawâqun 'colonnade', by a free interpretation of original text, similar to that one of the LXX and, first of all, of the Vulgate. So also this term, as its variant *parwār, is specified in the course of the semantic evolution happened in Judaism; in fact, in MSS of Qumran and in the Talmud, parbār is contextualized in the sense of 'colonnade, portico', as the Arabic terms used in Modern Versions attest, terms which have expressly such meaning.

Paraequilibrium Carburization of Duplex and Ferritic Stainless Steels

Science.gov (United States)

Michal, G. M.; Gu, X.; Jennings, W. D.; Kahn, H.; Ernst, F.; Heuer, A. H.

2009-08-01

AISI 301 and E-BRITE stainless steels were subjected to low-temperature (743 K) carburization experiments using a commercial technology developed for carburization of 316 austenitic stainless steels. The AISI 301 steel contained ~40 vol pct ferrite before carburization but had a fully austenitic hardened case, ~20- μm thick, and a surface carbon concentration of ~8 at. pct after treatment; this “colossal” paraequilibrium carbon supersaturation caused an increase in lattice parameter of ~3 pct. The E-BRITE also developed a hardened case, 12- to 18- μm thick, but underwent a more modest (~0.3 pct) increase in lattice parameter; the surface carbon concentration was ~10 at. pct. While the hardened case on the AISI 301 stainless steel appeared to be single-phase austenite, evidence for carbide formation was apparent in X-ray diffractometer (XRD) scans of the E-BRITE. Paraequilibrium phase diagrams were calculated for both AISI 301 and E-BRITE stainless steels using a CALPHAD compound energy-based interstitial solid solution model. In the low-temperature regime of interest, and based upon measured paraequilibrium carbon solubilities, more negative Cr-carbon interaction parameters for austenite than those in the current CALPHAD data base may be appropriate. A sensitivity analysis involving Cr-carbon interaction parameters for ferrite found a strong dependence of carbon solubility on relatively small changes in the magnitude of these parameters.

Experimental research of crucible steel: a new insight and historical reflection

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Klaas Remmen

2012-06-01

Full Text Available This paper describes experimental archaeo-metallurgical research on crucible steel, executed as a master project to obtain the master degree in conservation.  After evaluating the results of different manufacturing techniques, the so-called Georgian crucible steel technique showed results that were remarkably similar to archaeological evidence from Merv, Turkmenistan. An objective historical reflection was made.Cet article décrit une étude expérimentale archéo-métallurgique sur l'acier creuset, menée en tant que projet maîtrise pour l’obtention du grade de master en conservation et restauration. Après avoir évalué les résultats des techniques différentes de fabrication, la technique de l’acier au creuset géorgien a montré des résultats similaires aux preuves archéologiques de Merv, au Turkménistan. Une réflexion historique a été menée à ce sujet.

Super ODS steels R and D for fuel cladding of next generation nuclear systems. 5) Mechanical properties and microstructure

International Nuclear Information System (INIS)

Kasada, R.; Lee, S.G.; Lee, J.H.; Omura, T.; Zhang, C.H.; Dou, P.; Isselin, J.; Kimura, A.; Inoue, Masaki; Ukai, S.; Ohnuki, S.; Fujisawa, T.; Okuda, T.; Abe, F.

2009-01-01

The newly-developed Al-added ODS ferritic steels with an addition of Zr or Hf, so-called super ODS candidate steels, showed good notch-impact properties in the as-received condition with keeping the excellent creep strength. (author)

A Novel Methods for Fracture Toughness Evaluation of Tool Steels with Post-Tempering Cryogenic Treatment

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Ramona Sola

2017-02-01

Full Text Available Cryogenic treatments are usually carried out immediately after quenching, but their use can be extended to post tempering in order to improve their fracture toughness. This research paper focuses on the influence of post-tempering cryogenic treatment on the microstructure and mechanical properties of tempered AISI M2, AISI D2, and X105CrCoMo18 steels. The aforementioned steels have been analysed after tempering and tempering + cryogenic treatment with scanning electron microscopy, X-ray diffraction for residual stress measurements, and micro- and nano-indentation to determine Young’s modulus and plasticity factor measurement. Besides the improvement of toughness, a further aim of the present work is the investigation of the pertinence of a novel technique for characterizing the fracture toughness via scratch experiments on cryogenically-treated steels. Results show that the application of post-tempering cryogenic treatment on AISI M2, AISI D2, and X105CrCoMo18 steels induce precipitation of fine and homogeneously dispersed sub-micrometric carbides which do not alter hardness and Young’s modulus values, but reduce residual stresses and increase fracture toughness. Finally, scratch test proved to be an alternative simple technique to determine the fracture toughness of cryogenically treated steels.

Dislocation structures in 16MND5 pressure vessel steel strained in uniaxial tension

Czech Academy of Sciences Publication Activity Database

Obrtlík, Karel; Robertson, Ch.; Marini, B.

2005-01-01

Roč. 342, - (2005), s. 35-41 ISSN 0022-3115 R&D Projects: GA AV ČR(CZ) 1QS200410502 Institutional research plan: CEZ:AV0Z20410507 Keywords : bainitic steels * dislocation structure * low temperature deformation Subject RIV: JG - Metallurgy Impact factor: 1.414, year: 2005

In-Situ Subsurface Coating of Corroded Steel Sheet Pile Structures: Final Report on Project F08-AR06

Science.gov (United States)

2017-09-01

shrink cement grout or epoxy resin in the gap between old and new steel , shown in Figure 19. This was the reason why the perforated piles needed to...be made liquid-tight with cement grout or epoxy. Other- wise, the material injected between the old and new steel would be lost be- hind the old steel ...ER D C/ CE RL T R- 17 -3 5 DoD Corrosion Prevention and Control Program In-Situ Subsurface Coating of Corroded Steel Sheet Pile

Radiolabeling and in vitro and in vivo characterization of [18F]FB-[R(8,15,21), L17]-VIP as a PET imaging agent for tumor overexpressed VIP receptors.

Science.gov (United States)

Cheng, Dengfeng; Yin, Duanzhi; Li, Gucai; Wang, Mingwei; Li, Shiqiang; Zheng, Mingqiang; Cai, Hancheng; Wang, Yongxian

2006-12-01

In an effort to develop a peptide-based radiopharmaceutical for the detection of tumors overexpressed vasoactive intestinal peptide receptors with positron emission tomography, we have prepared a novel [R(8,15,21), L17]-VIP peptide for 18F-labeling. This peptide inhibited 125I-VIP binding to rats lung membranes with high affinity [half-maximal inhibitory concentrations (IC50) of 0.12 nm]. Additionally, [R(8,15,21), L17]-VIP showed higher stability than native vasoactive intestinal peptide in vivo of mice. With N-succinimidyl 4-[18F] fluorobenzoate as labeling prosthetic group, [18F]FB-[R(8,15,21), L17]-VIP was obtained in >99% radiochemical purity within 100 min in decay-for-corrected radiochemical yield of 33.6 +/- 3% (n = 5) and a specific radioactivity 255 GBq/micromol at the end of synthesis. Stability of [18F]FB-[R(8,15,21), L17]-VIP in vitro and in vivo were investigated. Biodistribution of this trace was carried out in mice with induced C26 colorectal tumor. Fast clearance of [18F]FB-[R(8,15,21), L17]-VIP from non-target tissues and specific uptakes by tumors realized higher tumor-to-muscle ratio (3.55) and tumor-to-blood ratio (2.37) 60 min postinjection. Clear difference was observed between the blocking and unblocking experiments in biodistribution and whole body radioautography. [18F]FB-[R(8,15,21), L17]-VIP has demonstrated its potential for diagnosing tumors overexpressed vasoactive intestinal peptide receptors both in vitro and in vivo.

3-D branching of magnetic domains on compressed si-fe steel with goss texture

Czech Academy of Sciences Publication Activity Database

Perevertov, Oleksiy; Schaefer, R.; Stupakov, Oleksandr

2014-01-01

Roč. 50, č. 11 (2014), s. 2007804 ISSN 0018-9464 R&D Projects: GA ČR GB14-36566G; GA ČR GA13-18993S Institutional support: RVO:68378271 Keywords : grain-oriented silicon steel * Kerr microscopy * magnetic domains * stress Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.386, year: 2014

Initial Stage of Oxidation of Iron and Steels Heated at High Temperatures Ambient

Czech Academy of Sciences Publication Activity Database

Adamaszek, K.; Kučera, Jaroslav

2001-01-01

Roč. 7, č. 1 (2001), s. 419-423 ISSN 1335-1532. [International Symposium on Metallography /11./. Stará Lesná, 25.04.2001-27.04.2001] R&D Projects: GA ČR GA106/01/0379; GA ČR GA106/01/0382 Institutional research plan: CEZ:AV0Z2041904 Keywords : iron * steels * oxidation Subject RIV: JG - Metallurgy

Fouling and biocorrosion of a high-alloy steel in the Golden Horn bay

International Nuclear Information System (INIS)

Koryakova, M.D.; Nikitin, V.M.; Suponina, A.P.; Kharchenko, U.V.; Zvyagintsev, A.Yu.

2002-01-01

The studies on the effect of contamination of the Golden Horn bay waters (the Peter the Great Bay in the Japanese Sea) on formation of the community of the bacterio- and macrofouling and corrosion resistance of the Kh18N10T high-alloy steel are continued. The dissolved and chemically absorbed oxygen, pH, saprophytes, oil-oxidizing, sulfate-reducing bacteria and heavy metals are among the medium indicators, characterizing the level of pollution of the regions of the samples testing. It is shown, that the obtained experimental data extend our understanding of the dependent effect of three factors: the sea medium → fouling → corrosion resistance of the Kh18N10T high-alloy steel [ru

Defects induced by swift heavy ions in the 18R martensite of Cu-Zn-Al alloy

International Nuclear Information System (INIS)

Zelaya, Eugenia; Tolley, Alfredo; Condo, Adriana; Lovey, Francisco; Schumacher, G

2003-01-01

The swift heavy ion incidence over the surface of a given material produces a strong energy deposition in a nanometric scale.Swift heavy ions, of the order of one thousand of MeV, deposit their energy as electronic excitations.This highly localized deposition can induce metastable transformations within the material. For example, in martensitic NiTi alloys irradiated with swift heavy ions, it has been observed changes on the martensitic transformation temperature and amorphous areas induced by the irradiation.In this work, the effects produced by swift heavy ions on the martensitic 18R structure of Cu-Zn-Al alloy (Cu - 12.17 Zn - 17.92 Al, in %at) were analyzed.Crystalline samples were irradiated in a direction close to the [2 1 0] of 18R with Xe + 230 MeV, Au + of 350 MeV and Kr + of 200 MeV ion beams.Defects of the order of nanometers induced by the irradiation were observed by transmission electron microscopy (TEM) and high resolution electron microscopy (HREM).It was also observed, that the average size of the irradiation defects induced by Au + ion is larger than those induced by Xe + and Kr + ions.In this case, no relationship between the observed defects and the energy deposition was found in the 23 keV/nn to 48 keV/nn range

18S rRNA is a reliable normalisation gene for real time PCR based on influenza virus infected cells

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Kuchipudi Suresh V

2012-10-01

Full Text Available Abstract Background One requisite of quantitative reverse transcription PCR (qRT-PCR is to normalise the data with an internal reference gene that is invariant regardless of treatment, such as virus infection. Several studies have found variability in the expression of commonly used housekeeping genes, such as beta-actin (ACTB and glyceraldehyde-3-phosphate dehydrogenase (GAPDH, under different experimental settings. However, ACTB and GAPDH remain widely used in the studies of host gene response to virus infections, including influenza viruses. To date no detailed study has been described that compares the suitability of commonly used housekeeping genes in influenza virus infections. The present study evaluated several commonly used housekeeping genes [ACTB, GAPDH, 18S ribosomal RNA (18S rRNA, ATP synthase, H+ transporting, mitochondrial F1 complex, beta polypeptide (ATP5B and ATP synthase, H+ transporting, mitochondrial Fo complex, subunit C1 (subunit 9 (ATP5G1] to identify the most stably expressed gene in human, pig, chicken and duck cells infected with a range of influenza A virus subtypes. Results The relative expression stability of commonly used housekeeping genes were determined in primary human bronchial epithelial cells (HBECs, pig tracheal epithelial cells (PTECs, and chicken and duck primary lung-derived cells infected with five influenza A virus subtypes. Analysis of qRT-PCR data from virus and mock infected cells using NormFinder and BestKeeper software programmes found that 18S rRNA was the most stable gene in HBECs, PTECs and avian lung cells. Conclusions Based on the presented data from cell culture models (HBECs, PTECs, chicken and duck lung cells infected with a range of influenza viruses, we found that 18S rRNA is the most stable reference gene for normalising qRT-PCR data. Expression levels of the other housekeeping genes evaluated in this study (including ACTB and GPADH were highly affected by influenza virus infection and

APT characterization of high nickel RPV steels

International Nuclear Information System (INIS)

Miller, M.K.; Russell, K.F

2004-01-01

Full text: The microstructures of several high nickel content pressure vessel steels have been characterized by atom probe tomography. The purposes of this study were to investigate the influence of high nickel levels on the response to neutron irradiation of high and low copper pressure vessel steels and to establish whether any additional phases were present after neutron irradiation. The nickel levels in these steels were at least twice that typically found in Western pressure vessel steels. Two different types of pressure vessel steels with low and high copper contents were selected for this study. The first set of alloys was low copper (∼0.05% Cu) base (15Ch2NMFAA) and weld (12Ch2N2MAA) materials used in a VVER-1000 reactor. The composition of the lower nickel VVER-1000 base material was Fe- 0.17 wt% C, 0.30% Si, 0.46% Mn, 2.2% Cr, 1.26% Ni, 0.05% Cu, 0.01% S, 0.008% P, 0.10% V and 0.50% Mo. The composition of the higher nickel VVER-1000 weld material was Fe- 0.06 wt % C, 0.33% Si, 0.80% Mn, 1.8% Cr, 1.78% Ni, 0.07% Cu, 0.009% S, 0.005% P, and 0.63% Mo. The VVER-1000 steels were irradiated in the HSSI Program's irradiation facilities at the University of Michigan, Ford Nuclear Reactor at a temperature of 288 o C for 2,137 h at an average flux of 7.08 x 10 11 cm 2 s -1 for a fluence of 5.45 x 10 18 n cm -2 (E >1 MeV) and for 5,340 h at an average flux of 4.33 x 10 11 cm -2 s -1 for a fluence of 8.32 x 10 1 28 n cm -2 (E >1 MeV). Therefore, the total fluence was 1.38 x 10 19 n cm -2 (E >1 MeV). The second type of pressure vessel steel was a high copper (0.20% Cu) weld from the Palisades reactor. The average composition of the Palisades weld was Fe- 0.11 wt% C, 0.18% Si, 1.27% Mn, 0.04% Cr, 1.20% Ni, 0.20% Cu, 0.017% S, 0.014% P, 0.003% V and 0.55% Mn. The Palisades weld, designated weldment 'B' from weld heat 34B009, was irradiated at a temperature of 288 o C and a flux of ∼7 x 10 11 cm -2 s -1 to a fast fluence of 1.4 x 10 19 n cm -2 (E >1 MeV). These three

Hollow-Core FRP–Concrete–Steel Bridge Columns under Torsional Loading

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Sujith Anumolu

2017-11-01

Full Text Available This paper presents the behavior of hollow-core fiber-reinforced polymer–concrete–steel (HC-FCS columns under cyclic torsional loading combined with constant axial load. The HC-FCS consists of an outer fiber-reinforced polymer (FRP tube and an inner steel tube, with a concrete shell sandwiched between the two tubes. The FRP tube was stopped at the surface of the footing, and provided confinement to the concrete shell from the outer direction. The steel tube was embedded into the footing to a length of 1.8 times the diameter of the steel tube. The longitudinal and transversal reinforcements of the column were provided by the steel tube only. A large-scale HC-FCS column with a diameter of 24 in. (610 mm and applied load height of 96 in. (2438 mm with an aspect ratio of four was investigated during this study. The study revealed that the torsional behavior of the HC-FCS column mainly depended on the stiffness of the steel tube and the interactions among the column components (concrete shell, steel tube, and FRP tube. A brief comparison of torsional behavior was made between the conventional reinforced concrete columns and the HC-FCS column. The comparison illustrated that both column types showed high initial stiffness under torsional loading. However, the HC-FCS column maintained the torsion strength until a high twist angle, while the conventional reinforced concrete column did not.

Cytogenetic analysis and chromosomal characteristics of the polymorphic 18S rDNA of Haliotis discus hannai from Fujian, China.

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Haishan Wang

Full Text Available We report on novel chromosomal characteristics of Haliotis discus hannai from a breeding population at Fujian, China. The karyotypes of H. discus hannai we obtained from an abalone farm include a common type 2n = 36 = 10M + 8SM (82% and two rare types 2n = 36 = 11M + 7SM (14% and 2n = 36 = 10M + 7SM + 1ST (4%. The results of silver staining showed that the NORs of H. discus hannai were usually located terminally on the long arms of chromosome pairs 14 and 17, NORs were also sometimes located terminally on the short arms of other chromosomes, either metacentric or submetacentric pairs. The number of Ag-nucleoli ranged from 2 to 8, and the mean number was 3.61 ± 0.93. Among the scored interphase cells, 41% had 3 detectable nucleoli and 37% had 4 nucleoli. The 18S rDNA FISH result is the first report of the location of 18S rDNA genes in H. discus hannai. The 18S rDNA locations were highly polymorphic in this species. Copies of the gene were observed in the terminal of long or/and short arms of submetacentric or/and metacentric chromosomes. Using FISH with probe for vertebrate-like telomeric sequences (CCCTAA3 displayed positive green FITC signals at telomere regions of all analyzed chromosome types. We found about 7% of chromosomes had breaks in prophase. A special form of nucleolus not previously described from H. discus hannai was observed in some interphase cells. It consists of many small silver-stained nucleoli gathered together to form a larger nucleolus and may correspond to prenucleolar bodies.

Genetic characterization and phylogenetic relationships based on 18S rRNA and ITS1 region of small form of canine Babesia spp. from India.

Science.gov (United States)

Mandal, M; Banerjee, P S; Garg, Rajat; Ram, Hira; Kundu, K; Kumar, Saroj; Kumar, G V P P S Ravi

2014-10-01

Canine babesiosis is a vector borne disease caused by intra-erythrocytic apicomplexan parasites Babesia canis (large form) and Babesia gibsoni (small form), throughout the globe. Apart from few sporadic reports on the occurrence of B. gibsoni infection in dogs, no attempt has been made to characterize Babesia spp. of dogs in India. Fifteen canine blood samples, positive for small form of Babesia, collected from northern to eastern parts of India, were used for amplification of 18S rRNA gene (∼1665bp) of Babesia sp. and partial ITS1 region (∼254bp) of B. gibsoni Asian genotype. Cloning and sequencing of the amplified products of each sample was performed separately. Based on sequences and phylogenetic analysis of 18S rRNA and ITS1 sequences, 13 were considered to be B. gibsoni. These thirteen isolates shared high sequence identity with each other and with B. gibsoni Asian genotype. The other two isolates could not be assigned to any particular species because of the difference(s) in 18S rRNA sequence with B. gibsoni and closer identity with Babesiaoccultans and Babesiaorientalis. In the phylogenetic tree, all the isolates of B. gibsoni Asian genotype formed a separate major clade named as Babesia spp. sensu stricto clade with high bootstrap support. The two unnamed Babesia sp. (Malbazar and Ludhiana isolates) clustered close together with B. orientalis, Babesia sp. (Kashi 1 isolate) and B. occultans of bovines. It can be inferred from this study that 18S rRNA gene and ITS1 region are highly conserved among 13 B. gibsoni isolates from India. It is the maiden attempt of genetic characterization by sequencing of 18S rRNA gene and ITS1 region of B. gibsoni from India and is also the first record on the occurrence of an unknown Babesia sp. of dogs from south and south-east Asia. Copyright © 2014 Elsevier B.V. All rights reserved.

Quasicrystalline and crystalline precipitation during isothermal tempering in a 12Cr-9Ni-4Mo maraging stainless steel

International Nuclear Information System (INIS)

Liu, P.; Stigenberg, A.H.; Nilsson, J.O.

1995-01-01

A thorough microstructural investigation has been performed on a high strength maraging steel of the type 12%Cr-9%Ni-4%Mo-2%Cu-1%Ti. The major precipitate formed during isothermal aging at 475 C is a quasicrystalline phase possessing icosahedral symmetry termed R'-phase with a typical chemical composition of 48%Mo-33%Fe-13%Cr-2%Ni-4%Si. At 550 C the major precipitate is trigonal R-phase with a typical composition of 45%Mo-31%Fe-18%Cr-4%Ni-2%Si. At 550 C also Laves phase with a composition of 48%Mo-35%Fe-13%Cr-2%Ni-2%Si could be observed. At both 475 and 550 C an ordered phase termed L-phase precipitated. This minority phase has an ordered face centered cubic (f.c.c.) structure of type L1 0 . Its composition is typically 9%Fe-4%Cr-52%Ni-15%Mo.-16%Ti-4%Al. R'-phase formed at 475 C transformed to R-phase and Laves phase during aging at 550 C. In an analogous manner, R-phase and Laves phase formed at 550 C transformed to R'-phase during subsequent aging at 475 C. This transformation was rationalized by a strong similarity in crystal structure between quasicrystalline R'-phase of icosahedral symmetry and Frank-Kasper phases such as R-phase and Laves phase

Effect of microstructure on low cycle fatigue properties of ODS steels

Czech Academy of Sciences Publication Activity Database

Kuběna, Ivo; Fournier, B.; Kruml, Tomáš

2012-01-01

Roč. 424, 1-3 (2012), s. 101-108 ISSN 0022-3115 R&D Projects: GA ČR GA106/09/1954; GA MŠk(CZ) ED1.1.00/02.0068 Institutional research plan: CEZ:AV0Z20410507 Keywords : ODS steels * low cycle fatigue * fusion energy Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 1.211, year: 2012

Microhardness of boron, titanium, and nitrogen implanted steel

International Nuclear Information System (INIS)

Sowa, M.; Szyszko, W.; Sielanko, J.; Glusiec, L.

1989-01-01

Mechanically polished steel (1H18N9T) and (15GTM) samples are implanted with boron, titanium, and nitrogen ions, with dose ranging from 10 16 to 10 17 ions/cm 2 . The implantation energy varied from 100 to 250 keV. Implanted samples are heat-treated at 400 to 800 0 C in vacuum. The microhardness of implanted samples is measured by using a Hanneman tester with loads ranging from 2 to 40 g. The influence of annealing temperature on microhardness of the implanted layers is determined. The diffusion of boron from the implanted layers is also investigated by using the secondary ion mass spectrometer. The diffusion coefficients of boron in steel are determined. (author)

Bridging from Brain to Tumor Imaging: (S-(−- and (R-(+-[18F]Fluspidine for Investigation of Sigma-1 Receptors in Tumor-Bearing Mice

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Mathias Kranz

2018-03-01

Full Text Available Sigma-1 receptors (Sig1R are highly expressed in various human cancer cells and hence imaging of this target with positron emission tomography (PET can contribute to a better understanding of tumor pathophysiology and support the development of antineoplastic drugs. Two Sig1R-specific radiolabeled enantiomers (S-(−- and (R-(+-[18F]fluspidine were investigated in several tumor cell lines including melanoma, squamous cell/epidermoid carcinoma, prostate carcinoma, and glioblastoma. Dynamic PET scans were performed in mice to investigate the suitability of both radiotracers for tumor imaging. The Sig1R expression in the respective tumors was confirmed by Western blot. Rather low radiotracer uptake was found in heterotopically (subcutaneously implanted tumors. Therefore, a brain tumor model (U87-MG with orthotopic implantation was chosen to investigate the suitability of the two Sig1R radiotracers for brain tumor imaging. High tumor uptake as well as a favorable tumor-to-background ratio was found. These results suggest that Sig1R PET imaging of brain tumors with [18F]fluspidine could be possible. Further studies with this tumor model will be performed to confirm specific binding and the integrity of the blood-brain barrier (BBB.

intercritical heat treatments effects on low carbon steels quenched

African Journals Online (AJOL)

DR B. A. EZEKOYE

Department of Physics and Astronomy, University of Nigeria, Nsukka. 2. E-mail: benjamin.ezekoye@unn.edu.ng; bezekoye@yahoo.com. ABSTRACT. Six low carbon steels containing carbon in the range 0.13-0.18wt%C were studied after intercritical quenching, intercritical quenching with low temperature tempering, ...

Radiation blistering of stainless steel

International Nuclear Information System (INIS)

Yoshii, Naritsugu; Tanabe, Tetsuo; Imoto, Shosuke

1980-01-01

Surface blistering of stainless steels due to 20 keV He + ion bombardment has been investigated by examination of surface topography with a scanning electron microscope (SEM) and an optical microscope. Blisters of 0.1 to 2 μm in diameter are observed in all samples irradiated with fluence of about 1 x 10 18 He + /cm 2 at any temperature between -80 0 C and 500 0 C. With increasing the fluence blister covers are ruptured and exfoliated and finally the surface becomes rough surface without traces of blister formation. The surface effect is severer at 500 0 C than at 100 0 C irradiation. Also in double-phase stainless steel DP-3, similar surface topography to 316 SS is observed. But by the difference of the erosion rate by sputtering of the surface between α-phase and γ-phase, a striped pattern appears in DP-3 with heavy irradiation of about 2 x 10 19 He + /cm 2 . (author)

Development of high yield strength non-magnetic steels for the equipments of nuclear fusion research

International Nuclear Information System (INIS)

Matsuoka, Hidenori; Mukai, Tetsuya; Ohtani, Hiroo; Tsuruki, Takanori; Okada, Yasutaka

1979-01-01

Recently, activity of nuclear fusion research and so forth increase the demand of non-magnetic materials for various equipments and structures. For these usage, very low magnetic permeability as well as high strength are required under high magnetic field. Based on fundamental research, middle C-17% Cr-7% Ni-N non-magnetic steel has been developed. The developed steel shows more stable austenite phase and possesses higher yield strength and endurance limit of more than 10 kg/mm 2 , compared with 18% Cr-8% Ni austenitic steel. Also the developed steel has good ductility and toughness in spite of the high yield strength and shows better machinability than usual high Mn non- magnetic steels. The large forgings of this newly developed steel are manufactured in the works for the equipments of nuclear fusion research and confirmed good mechanical properties, high fatigue strength and low permeability. (author)

Effect of microbial treatment on the prevention and removal of paraffin deposits on stainless steel surfaces.

Science.gov (United States)

Xiao, Meng; Li, Wen-Hong; Lu, Mang; Zhang, Zhong-Zhi; Luo, Yi-Jing; Qiao, Wei; Sun, Shan-Shan; Zhong, Wei-Zhang; Zhang, Min

2012-11-01

In this study, biosurfactant-producing strain N2 and non-biosurfactant producing stain KB18 were used to investigate the effects of microbial treatment on the prevention and removal of paraffin deposits on stainless steel surfaces. Strain N2, with a biosurfactant production capacity, reduced the contact angle of stainless steel to 40.04°, and the corresponding adhesion work of aqueous phase was decreased by 26.5 mJ/m(2). By contrast, KB18 could only reduce the contact angle to 50.83°, with a corresponding 7.6 mJ/m(2) decrease in the aqueous phase work adhesion. The paraffin removal test showed that the paraffin removal efficiencies of strain N2 and KB18 were 79.0% and 61.2%, respectively. Interestingly, the N2 cells could attach on the surface of the oil droplets to inhibit droplets coalescence. These results indicate that biosurfactant-producing strains can alter the wettability of stainless steel and thus eliminate paraffin deposition. Copyright © 2012 Elsevier Ltd. All rights reserved.

Outlook of the world steel cycle based on the stock and flow dynamics.

Science.gov (United States)

Hatayama, Hiroki; Daigo, Ichiro; Matsuno, Yasunari; Adachi, Yoshihiro

2010-08-15

We present a comprehensive analysis of steel use in the future compiled using dynamic material flow analysis (MFA). A dynamic MFA for 42 countries depicted the global in-use stock and flow up to the end of 2005. On the basis of the transition of steel stock for 2005, the growth of future steel stock was then estimated considering the economic growth for every country. Future steel demand was estimated using dynamic analysis under the new concept of "stocks drive flows". The significant results follow. World steel stock reached 12.7 billion t in 2005, and has doubled in the last 25 years. The world stock in 2005 mainly consisted of construction (60%) and vehicles (10%). Stock in these end uses will reach 55 billion t in 2050, driven by a 10-fold increase in Asia. Steel demand will reach 1.8 billion t in 2025, then slightly decrease, and rise again by replacement of buildings. The forecast of demand clearly represents the industrial shift; at first the increase is dominated by construction, and then, after 2025, demand for construction decreases and demand for vehicles increases instead. This study thus provides the dynamic mechanism of steel stock and flow toward the future, which contributes to the design of sustainable steel use.

Experiments on 18-8 stainless steels exposed to liquid lithium. I. 1,100-hour corrosion tests in lithium of 400, 500 and 6000C in natural circulation type testing apparatus

International Nuclear Information System (INIS)

Nihei, I.; Sumiya, I.; Fukaya, Y.; Yamazaki, Y.

The Japan Atomic Energy Research Institute has planned and started to carry out a series of experiments concerning fusion reactor materials. This report gives the results of the first experiments. The first test materials selected were 18-8 stainless steels, and the experiments were designed to test their behavior when exposed to liquid lithium. Natural circulation type corrosion testing devices (pots) were used as the testing apparatus, and the tests were conducted with lithium temperatures up to 600 0 C

The potential significance of microalloying with niobium in governing very high cycle fatigue behavior of bainite/martensite multiphase steels

International Nuclear Information System (INIS)

Zhao, P.; Cheng, C.; Gao, G.; Hui, W.; Misra, R.D.K.; Bai, B.; Weng, Y.

2016-01-01

We elucidate here the effect of microalloying with niobium (Nb) on very high cycle fatigue (VHCF) behavior in high-strength C–Mn–Si–Cr bainite/martensite (B/M) multiphase steels studied through ultrasonic fatigue testing. The tensile strength (R_m) and fatigue limit strength after 10"9 cycles (σ_w_9) and in the non-failure condition of the steel microalloyed with Nb were 1640 MPa and 900 MPa, respectively. Thus, the value of σ_w_9/R_m exceeded in comparison to conventional steels and was approximate 0.55. Three types of failure modes were observed in Nb-bearing steels depending on the surface condition, inclusion, and the matrix microstructure, i.e., surface defect-induced failure mode (S-mode), inclusion-induced failure mode (I-mode), and non-inclusion induced failure mode (N-mode). Only two failure modes were observed in Nb-free steels, the S-mode and the N-mode. The study clearly suggests that Nb had a distinct effect on the VHCF properties of B/M steels. The VHCF limit of Nb-bearing steel was enhanced by 200 MPa because of refinement of the microstructure and pinning of dislocations by randomly distributed nanometer-sized Nb(C, N) precipitates. It is underscored that microalloying with Nb is a potential approach to enhance VHCF properties in advanced high-strength steels.

Corrosion behaviour of stainless steels by internal friction method

International Nuclear Information System (INIS)

Postnikov, V.S.; Kovalevskij, V.I.

1987-01-01

Corrosion of austenite chromium-nickel stainless steels 12 Kh18N9, 12Kh18N9T, 12Kh18N10 and 12Kh18N10T is investigated. Wire samples 0.7...0.8 mm in diameter before tests were subjected to quenching in water from the temperature of 1050...1100 deg C and part of them - to tempering at 650 deg C for 2 h. Pitting corrosion was brought about by different concentration of iron chloride solutions (C FeCl 3 ). Total corrosion has a slight effect on the character of IF (internal friction) variation that increases without the whole test period up to the moment when mechanical strength of the sample

T cell expression of IL-18R and DR3 is essential for non-cognate stimulation of Th1 cells and optimal clearance of intracellular bacteria.

Science.gov (United States)

Pham, Oanh H; O'Donnell, Hope; Al-Shamkhani, Aymen; Kerrinnes, Tobias; Tsolis, Renée M; McSorley, Stephen J

2017-08-01

Th1 cells can be activated by TCR-independent stimuli, but the importance of this pathway in vivo and the precise mechanisms involved require further investigation. Here, we used a simple model of non-cognate Th1 cell stimulation in Salmonella-infected mice to examine these issues. CD4 Th1 cell expression of both IL-18R and DR3 was required for optimal IFN-γ induction in response to non-cognate stimulation, while IL-15R expression was dispensable. Interestingly, effector Th1 cells generated by immunization rather than live infection had lower non-cognate activity despite comparable IL-18R and DR3 expression. Mice lacking T cell intrinsic expression of MyD88, an important adapter molecule in non-cognate T cell stimulation, exhibited higher bacterial burdens upon infection with Salmonella, Chlamydia or Brucella, suggesting that non-cognate Th1 stimulation is a critical element of efficient bacterial clearance. Thus, IL-18R and DR3 are critical players in non-cognate stimulation of Th1 cells and this response plays an important role in protection against intracellular bacteria.

Evolutionary insight on localization of 18S, 28S rDNA genes on homologous chromosomes in Primates genomes

Science.gov (United States)

Mazzoleni, Sofia; Rovatsos, Michail; Schillaci, Odessa; Dumas, Francesca

2018-01-01

Abstract We explored the topology of 18S and 28S rDNA units by fluorescence in situ hybridization (FISH) in the karyotypes of thirteen species representatives from major groups of Primates and Tupaia minor (Günther, 1876) (Scandentia), in order to expand our knowledge of Primate genome reshuffling and to identify the possible dispersion mechanisms of rDNA sequences. We documented that rDNA probe signals were identified on one to six pairs of chromosomes, both acrocentric and metacentric ones. In addition, we examined the potential homology of chromosomes bearing rDNA genes across different species and in a wide phylogenetic perspective, based on the DAPI-inverted pattern and their synteny to human. Our analysis revealed an extensive variability in the topology of the rDNA signals across studied species. In some cases, closely related species show signals on homologous chromosomes, thus representing synapomorphies, while in other cases, signal was detected on distinct chromosomes, leading to species specific patterns. These results led us to support the hypothesis that different mechanisms are responsible for the distribution of the ribosomal DNA cluster in Primates. PMID:29416829

Evolutionary insight on localization of 18S, 28S rDNA genes on homologous chromosomes in Primates genomes

Directory of Open Access Journals (Sweden)

Sofia Mazzoleni

2018-01-01

Full Text Available We explored the topology of 18S and 28S rDNA units by fluorescence in situ hybridization (FISH in the karyotypes of thirteen species representatives from major groups of Primates and Tupaia minor (Günther, 1876 (Scandentia, in order to expand our knowledge of Primate genome reshuffling and to identify the possible dispersion mechanisms of rDNA sequences. We documented that rDNA probe signals were identified on one to six pairs of chromosomes, both acrocentric and metacentric ones. In addition, we examined the potential homology of chromosomes bearing rDNA genes across different species and in a wide phylogenetic perspective, based on the DAPI-inverted pattern and their synteny to human. Our analysis revealed an extensive variability in the topology of the rDNA signals across studied species. In some cases, closely related species show signals on homologous chromosomes, thus representing synapomorphies, while in other cases, signal was detected on distinct chromosomes, leading to species specific patterns. These results led us to support the hypothesis that different mechanisms are responsible for the distribution of the ribosomal DNA cluster in Primates.

Corrosion resistance of hsla steel after various surface treatments in chloride environment

Czech Academy of Sciences Publication Activity Database

Borko, K.; Pastorek, F.; Fintová, Stanislava; Hadzima, B.

2016-01-01

Roč. 18, č. 4 (2016), s. 99-102 ISSN 1335-4205 Institutional support: RVO:68081723 Keywords : Corrosion properties * Iron phosphating * S355J steel Subject RIV: JK - Corrosion ; Surface Treatment of Materials

Texture evolution in Fe-3% Si steel treated under unconventional annealing conditions

Czech Academy of Sciences Publication Activity Database

Stoyka, V.; Kováč, F.; Stupakov, Oleksandr; Petryshynets, I.

2010-01-01

Roč. 61, č. 11 (2010), 1066-1073 ISSN 1044-5803 R&D Projects: GA ČR GP102/09/P108 Institutional research plan: CEZ:AV0Z10100520 Keywords : grain oriented steels * annealing * abnormal grain growth * crystallographic texture * hysteresis losses * electron backscattering Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.496, year: 2010

The near-threshold high R-ratio fatigue crack growth characteristics of SA508 cl III reactor pressure vessel steel

International Nuclear Information System (INIS)

Achilles, R.D.; Bulloch, J.H.

1989-01-01

This paper describes the effect of frequency and environment on the near-threshold fatigue crack growth behaviour of SA508 cl III reactor pressure vessel (RPV) steel. The study has shown that in the near-threshold regime microstructure and environment markedly affect fatigue crack growth behaviour. In an aqueous environment, fatigue crack growth behaviour became even more sensitive to microstructure, and the fatigue crack growth rate increased by a factor of four in the case of the 3Hz test, while that for the 0.3Hz test was increased by a factor of approximately sixteen. This environmental enhancement manifested itself in the form of intergranular failure. For the 0.3Hz test the percentage intergranular failure decreased from 18% to <1% with an increase in ΔK level. The transition from microstructure-sensitive to microstructure-insensitive occurs when the cyclic plastic zone size is of the order of the prior austenite grain size. (author)

Super ODS steels R and D for fuel cladding of next generation nuclear systems. 4) Mechanical properties at elevated temperatures

International Nuclear Information System (INIS)

Furukawa, Tomohiro; Ohtsuka, Satoshi; Inoue, Masaki; Okuda, Takanari; Abe, Fujio; Ohnuki, Somei; Fujisawa, Toshiharu; Kimura, Akihiko

2009-01-01

As fuel cladding material for lead bismuth-cooled fast reactors and supercritical pressurized water-cooled fast reactors, our research group has been developing highly corrosion-resistant oxide dispersion strengthened ferritic steels with superior high-temperature strength. In this study, the mechanical properties of super ODS steel candidates at elevated temperature have been evaluated. Tensile tests, creep tests and low cycle fatigue tests were carried out for a total of 21 types of super ODS steel candidates which have a basic chemical composition of Fe-16Cr-4Al-0.1Ti- 0.35Y 2 O 3 , with small variations. The testing temperatures were 700degC (for tensile, creep and low cycle fatigue tests) and 450degC (for tensile test). The major alloying parameters of the candidate materials were the compositions of Cr, Al, W and the minor elements such as Hf, Zr and Ce etc. The addition of the minor elements is considered effective in the control of the formation of the Y-Al complex oxides, which improves high-temperature strength. The addition of Al was very effective for the improvement of corrosion resistance. However, the addition also caused a reduction in high-temperature tensile strength. Among the efforts aimed at increasing high-temperature strength, such as the low-temperature hot-extrusion process, solution strengthening by W and the addition of minor elements, a remarkable improvement of strength was observed in ODS steel with a basic chemical composition of 2W-0.6Hf steel (SOC-14) or 2W-0.6Zr steel (SOC-16). The same behavior was also observed in creep tests, and the creep rupture times of SOC-14 and SOC-16 at 700degC - 100MPa were greater than 10,000 h. The strength was similar to that of no-Al ODS steels. No detrimental effect by the additional elements on low-cycle fatigue strength was observed in this study. These results showed that the addition of Hf/Zr to ODS-Al steels was effective in improving high-temperature strength. (author)

Corrosion of austenitic steels and their components in vanadium-containing chloride melts

Science.gov (United States)

Abramov, A. V.; Polovov, I. B.; Rebrin, O. I.; Lisienko, D. G.

2014-08-01

The corrosion of austenitic 12Kh18N10T, 10Kh17N13M2T, and 03Kh17N14M3 steels and their components (Cr, Fe, Ni, Mo) in NaCl-KCl-VCl2 melts with 5 wt % V at 750°C is studied. The rates and mechanisms of corrosion of the materials under these conditions are determined. The processes that occur during contact of the metals and steels with vanadium-containing chloride electrolytes are investigated.

Spatial structure determination of ({radical}3 x {radical}3)R30{degrees} and (1.5 x 1.5)R18{degrees}CO on Cu(111) using angle-resolved photoemission extended fine structure

Energy Technology Data Exchange (ETDEWEB)

Moler, E.J.; Kellar, S.A.; Huff, W.R.A. [Lawrence Berkeley National Lab., CA (United States)] [and others

1997-04-01

The authors report a study of the spatial structure of ({radical}3 x {radical}3)R30{degrees} (low coverage) and (1.5 x 1.5)R18{degrees} (intermediate coverage) CO adsorbed on Cu(111), using the Angle-Resolved Photoemission Extended Fine Structure (ARPEFS) technique at beamline 9.3.2 at the Advanced Light Source. The CO molecule adsorbs on an atop site for both adsorption phases. Full multiple-scattering spherical-wave (MSSW) calculations were used to extract the C-Cu. bond length and the first Cu-Cu layer spacing for each adsorption phase. The authors find that the C-Cu bond length remains unchanged with increasing coverage, but the 1st Cu-Cu layer spacing contracts at the intermediate coverage. They calculate the bending mode force constant in the (1.5 x 1.5)R18{degrees} phase to be K{sub {delta}} = 2.2 (1) x 10{sup {minus}12} dyne-cm/rad from their experimentally determined bond lengths combined with previously published infra-red absorption frequencies.

Fatigue crack growth in ferritic steels as influence by elevated temperature and environment

International Nuclear Information System (INIS)

Nakamura, H.; Minakawa, K.; Murali, K.; Mc Evily, A.J.

1987-01-01

Fatigue crack growth studies have been carried out at room temperature and at 538 deg C in air as well as in vacuum in order to assess the influence of both temperature and environment on the growth process. The materials investigated were 2 1/4Cr-1Mo steel, a modified 9Cr-1Mo steel and a 9Cr-2Mo steel, as well as weldments of the 9Cr-2Mo steel. Crack opening levels were determined for all test conditions. The R-dependency of the crack growth rate could be accounted for by crack closure, both at room and elevated temperature. Closure in air at 538 deg C was due to oxidation, whereas at room temperature closure was due to microstructurally related roughness and the influence of oxygen. (Author)

The Study on Weldability of Boron Steel and Hot-Stamped Steel by Using Laser Heat Source (Ⅲ) - Comparison on Laser Weldability of Boron Steel and Hot -Stamped Steel-

Energy Technology Data Exchange (ETDEWEB)

Choi, So Young; Kim, Jong Do [Korea Maritime and Ocean University, Busan (Korea, Republic of); Kim, Jong Su [Korea Institute of Machinery and Materials, Daejeon (Korea, Republic of)

2015-01-15

This study was conducted to compare the laser weldability of boron steel and hot-stamped steel. In general, boron steel is used in the hot-stamping process. Hot-stamping is a method for simultaneously forming and cooling boron steel in a press die after heating it to the austenitizing temperature. Hot-stamped steel has a strength of 1500 MPa or more. Thus, in this study, the laser weldability of boron steel and that of hot-stamped steel were investigated and compared. A continuous wave disk laser was used to produce butt and lap joints. In the butt welding, the critical cooling speed at which full penetration was obtained in the hot-stamped steel was lower than that of boron steel. In the lap welding, the joint widths were similar regardless of the welding speed when full penetration was obtained.

The Study on Weldability of Boron Steel and Hot-Stamped Steel by Using Laser Heat Source (Ⅲ) - Comparison on Laser Weldability of Boron Steel and Hot -Stamped Steel-

International Nuclear Information System (INIS)

Choi, So Young; Kim, Jong Do; Kim, Jong Su

2015-01-01

This study was conducted to compare the laser weldability of boron steel and hot-stamped steel. In general, boron steel is used in the hot-stamping process. Hot-stamping is a method for simultaneously forming and cooling boron steel in a press die after heating it to the austenitizing temperature. Hot-stamped steel has a strength of 1500 MPa or more. Thus, in this study, the laser weldability of boron steel and that of hot-stamped steel were investigated and compared. A continuous wave disk laser was used to produce butt and lap joints. In the butt welding, the critical cooling speed at which full penetration was obtained in the hot-stamped steel was lower than that of boron steel. In the lap welding, the joint widths were similar regardless of the welding speed when full penetration was obtained

Contribution to the study of the kinetics of maraging steel aging

International Nuclear Information System (INIS)

Santos Victor, O.B. dos.

1990-01-01

Maraging steels are materials with very low contents of C and with Ni, Co, Mo and T1 additions, that can reach very high mechanical strength values by combinations of heat treatment operations. Three 18% Ni Maraging steels have had some aspects of their aging kinetics investigated by experimental procedures using electrical resistivity, internal friction and hardness measurement techniques, in samples aged from 30 seconds to several hours. Finally, it was verified that the techniques employed were very adequate to the purposes of the present kinetics studies. (author)

Evaluation of frictional resistance between monocrystalline (ICE brakcets and Stainless Steel, Beta TMA and NiTiarch wires

Directory of Open Access Journals (Sweden)

Meysam Mirzaie

2013-09-01

Full Text Available Introduction: When using sliding mechanics for space closure during orthodontic treatment, friction occurs at the bracket-wire interface. The aim of this study was to evaluate the frictional resistance between monocrystalline (ICE brackets and Stainless Steel, Beta TMA and NiTi wires. Methods: In this experimental study, we used 5 different types of orthodontic wires. Brackets and wires were divided in to 5 groups: 1-(monocrystalline+stainless steel 18 2–(monocrystalline+stainless steel 19×25 3-(monocrystalline+Beta-TMA 4–(monocrystalline+Beta TMA 19×25 5-(monocrystalline+NiTi 18. Instron Universal Testing Machine was used to investigate the static frictional resistance. The angulation between bracket and wire was 0 and the wires were pulled through the slots at a speed of 10 mm/min. Tests were performed 10 times for each group in artificial saliva. The average of 10 forces recorded was considered as static friction. One-way ANOVA and SPSS Version 18 and LSD post hoc test were used to evaluate the results of the study. Results: The mean static frictional force for each group was: group1: 0.82 ± 0.14, group 2: 1.09 ± 0.30, group 3: 0.87 ± 0.53, group 4: 1.9 ± 1.16, group 5: 1.42 ± 0.30. There was a significant difference when comparing the two groups of similar wires in terms of shape (round or rectangular cross-section as when comparing Beta TMA 18 and 19×25 arch wires with each other, the obtained p-value was 0.023, while the obtained p-value for the comparison of stainles steel arch wires was 0.034 . Conclusions: The result of this study shows that Stainless Steel 18 wires generate the least amount of friction and round wires produce less friction than the rectangular wires. Beta TMA wires generate the highest amount of friction.

Dynamic fracture testing of ferritic steels using direct current potential drop method

International Nuclear Information System (INIS)

Oh, Y. J.; Kim, J. H.; Hwang, I. S.; Park, Y. W.

2000-01-01

To apply leak-before-break (LBB) concept to nuclear pipes, the dynamic strain aging of low carbon steel materials has to be considered. For this goal, the J-R tests are needed over a range of temperatures and loading rates, including rapid dynamic loading conditions. In dynamic J-R tests, the unloading compliance method can not be applied and usually the direct current potential drop (DCPD) method has been used. But, even the DCPD method was known to have the problem in defining the crack initiation point due to a potential peak arising in early part of loading of ferromagnetic materials. In this study, potential peaks characteristics were investigated for SA106Gr.C piping steels, and the definition of crack initiation point was made by back tracking from final physical crack length, and it was proposed that this technique could be applied to DCPD method in dynamic loading J-R test