Download or read book Effects of Neutron Flux and Irradiation Temperature on Irradiation Embrittlement of A533B Steels written by M. Kizaki and published by . This book was released on 1996 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Irradiation embrittlement of A533B steels with low copper contents were investigated from the point of dose rate and irradiation temperature effects. Change of neutron flux in the range from -1012 to -1013 n/cm2/s (E> 1MeV) did not have a significant effect on the embrittlement. Irradiation temperature change of 1°C resulted in the transition temperature shift (?T41J) of about 1°C and yield stress change (?oy) of about 0.8MPa. Factors that might affect the embrittlement of low copper steels are also discussed.

Download or read book Effects of Neutron Dose Dose Rate and Irradiation Temperature on the Irradiation Embrittlement of a Low Copper Reactor Pressure Vessel Steel written by M. Narui and published by . This book was released on 2005 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: A series of irradiation experiments to investigate the effects of neutron fluence and flux on reactor pressure vessel (RPV) steels has been performed using the Japan Material Testing Reactor (JMTR). The irradiation temperature has been precisely controlled at 290°C within an error of ±2°C during reactor operation. The neutron fluence and flux ranged from 9.3 × 1017 to 1.1 × 1020 n/cm2 and from 1.4 × 1011 to 6.3 × 1013 n/cm2/s, respectively. The material used in the present study was an A533B RPV steel in which the copper and phosphorous concentrations are 0.03 and 0.002 wt%, respectively. Charpy impact test results with one-third sized specimens showed no dose-rate dependence. Microstructural observation revealed that a higher irradiation temperature at around 340°C resulted in formation of rather large dislocation loops and smaller microvoids.

Download or read book Effects Of Irradiation Temperature on Embrittlement of Nuclear Pressure Vessel Steels written by FM. Haggag and published by . This book was released on 1994 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of neutron irradiation on the steel reactor vessel for the modular high-temperature gas-cooled reactor (MHTGR) are eing investigated, primarily because the operating temperatures are low [121 to 288°C (250-550°F)] compared to those for commercial light-water reactors (LWRs) [~288°C (550°F)]. The need for design data on the reference temperature (RTNDT) shift necessitated the irradiation at different temperatures of A 533 grade B class 1 plates, A 508 class 3 forging, and welds used for the vessel shell, vessel closure head, and vessel flange. This paper presents regular- and mini-tensile, Automated Ball Indentation (ABI), and Charpy V-notch (CVN) impact test results from five irradiation capsules of this program. The first four capsules were irradiated in the University of Buffalo Reactor (UBR) to an effective fast fluence of 1.1 x 1018 neutrons/cm2 [0.7 x 1018 neutrons/cm2 (>1 MeV)] at temperatures of 288, 204, 163, and 121°C (550, 400, 325, and 250°F), respectively. The fifth capsule (designated ORNL-7) was irradiated in the Ford Nuclear Reactor (FNR) of the University of Michigan at 60°C (140°F) to an effective fast fluence of 1.3 x 1018 neutrons/cm2 [0.8 x 1018 neutrons/cm2 (>1 MeV)]. The yield and ultimate strengths of both A 533 grade B class 1 plate materials of the MHTGR program increased with decreasing irradiation temperature. Similarly, the 41-J CVN transition temperature shift increased with decreasing irradiation temperature (in agreement with the increase in yield strength). The mini-tensile and Automated Ball Indentation (ABI) test results (yield strength and flow properties) were in good agreement with those from standard tensile specimens. The mini-tensile and ABI test results were also used in a model which utilizes the changes in yield strength to estimate the CVN ductile-to-brittle transition temperature shift due to irradiation. The model predictions were compared with CVN test results obtained here and in earlier work.

Download or read book Effect of Neutron Irradiation on the Impact Properties of A533B Steel written by and published by . This book was released on 1994 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new methodology is proposed to correlate the upper shelf energy (USE) of full size and subsize Charpy specimens of a nuclear reactor pressure vessel plate material, ASTM type A 533 Grade B (A533B) having a low USE (USE 100 J). The methodology appears to be more satisfactory than those methodologies proposed earlier. The USE was normalized by a normalization factor involving the dimensions of the Charpy specimen, the elastic stress concentration factor, and the plastic constraint at the notch root. The normalized values of the USE were found to be invariant with specimen size. In addition, it was also found that the ratio of the USE of unirradiated to that of irradiated materials was approximately the same for full, half, and third size specimens. The ductile-to-brittle transition temperature (DBTT) increased due to irradiation at 150 C to a nominal fluence of 1.0 x 1019 n/cm2 (E 1 MeV) by 78 °, 83°, and 70°C for full, half, and third size specimens, respectively. These shifts in DBTT appeared to be independent of specimen size and notch geometry.

Download or read book Effects of Radiation on Materials written by D. S. Gelles and published by ASTM International. This book was released on 1996 with total page 1169 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Neutron Radiation on Notched Bend and Tensile Properties of ASTM A 201A Carbon Steel written by R. L. Mehan and published by . This book was released on 1957 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effect of Nuclear Radiation on Structural Metals written by Frederic R. Shober and published by . This book was released on 1961 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of fast-neutron (>1 Mev) irradiation on the mechanical properties of structural metals and alloys was studied. Although the yield strengths and ultimate tensile strengths are increased su stantially for most materials, the ductility suffers severe decreases. This report presents these changes in properties of several structural metals for a number of neutron exposures within the 1.0 x 10 to the 18th power to 5.0 x 10 to the 21st power n/sq cm range. Data summarizing these effects on several classes of materials such as carbon steels, low-alloy steels, stainless steels, Zr-base alloys, ni-base alloys, Al-base alloys, and Ta are given. Additional data which show the influence f irradiation temperatures and of post-irradiation annealing on the radiation-induced property changes are also given and discussed. Increases as great as 175% in yield strength, 100% in ultimate strength, and decreases of 80% in total elongation are reported for fast-neutron exposures as great as 5 10 to the 21st power n/sq cm. (Author).

Download or read book Overview of U S Research and Regulatory Activities on Neutron Radiation Embrittlement of Pressure Vessel Steel written by PN. Randall and published by . This book was released on 1989 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper is in several parts: the first presents an overview of research activities sponsored by the U.S. Nuclear Regulatory Commission (NRC) on neutron irradiation embrittlement of pressure vessel steels. A series of irradiation experiments have evaluated effects of chemistry on the fracture toughness properties of submerged arc welds representing current nuclear vessel fabrication practices and provide data to validate ASME Code practices. A correlation between Charpy energy and fracture toughness is being studied as is a program on radiation sensitivity to define the role of dose rate and to study the effects of postirradiation heat treatment (annealing). The development of a comprehensive data base for radiation embrittlement data has been initiated and is being applied in a correlation of reactor surveillance data with test reactor data. A comprehensive dosimetry effort has produced validated standard methods for calculating and measuring neutron flux and fluence parameters and the correlation of these parameters to embrittlement of pressure vessel steels in light water reactors. Our knowledge of radiation damage to reactor vessels has also been greatly increased in recent years by the accumulation of power reactor surveillance data and by better models and better analysis techniques applied to that data. Unfortunately, the results show that radiation damage is often more than previously predicted, using Revision 1 of NRC Regulatory Guide 1.99, and will result in more restrictive pressure temperature limits. The second part of this paper describes some of the system and operational impacts produced, which in turn lead to challenges to long-established safety margins. Finally, a number of outstanding issues which require further research are discussed, many of which will require better understanding of radiation damage mechanisms.

Download or read book The Effects of Flux on Radiation Embrittlement of Low Copper Pressure Vessel Steels written by C. Zhang and published by . This book was released on 2000 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of neutron flux (E>1MeV) on the radiation embrittlement of the low-copper RPV steels are investigated. Tested materials include the forging matrix (JF) weld (JW) of Japan's SA 508-3 steel as well as the matrix (CF) and weld (CW) of China's domestic RPV steel. JF and CF were irradiated to fluences from 3.2 to 4.9 x 1023n/m2(E>1MeV) at 280±5°C, JW and CW irradiated to fluences of 1.4 and 1.5 x 1023n/m2 at 290±5°C, respectively, in the test reactor. JF and JW are also used as surveillance specimens for PWR RPV, and two sets of surveillance data have been acquired. The experimental results indicate that the transition temperature shifts (?RTNDT) for JF irradiated in the test reactor are larger than those from surveillance specimens, when these ?RTNDT are normalized to an effective fluence of 2x1023n/m2 (E>1MeV) and an effective temperature of 290°C. This shows notably the influence of neutron flux on ?RTNDT. The mean ?RTNDT for CF and CW is about 0.7 times that for JF and JW in terms of the normalized data, which imply the influences of the impurities besides Cu and microstructures on radiation embrittlement of low-copper RPV steels.

Download or read book Radiation Effects on Toughness of Ferritic Steels for Reactor Vessels written by L. P. Trudeau and published by . This book was released on 1964 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Irradiation Induced Grain Boundary Solute Segregation and Its Effect on Ductile to Brittle Transition Temperature in Reactor Pressure Vessel Steels written by Masatake Yamaguchi and published by . This book was released on 2009 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: A study on grain-boundary segregation and embrittlement in terms of the Charpy ductile-to-brittle transition temperature (DBTT) has been performed for the neutron-irradiated A533B steels with typical contents of impurities of Japanese reactor pressure vessel ones. The neutron irradiation was conducted at 563 K to a fluence of 1.3 x 1024n/m2 (E>1 MeV) using material testing reactors. The neutron irradiation induced the P and Ni segregation and the reduction in C in some cases at grain-boundaries. The increase in the P segregation at high fluence (>5 x 10 23n/m2, E>1 MeV) was less than 0.1 in monolayer coverage for the steels with the bulk content of P not exceeding 0.02 wt%. The hardening more strongly affected the DBTT shift than the P segregation for those steels. The reduction in segregated C that enhances the grain-boundary cohesion by neutron fluence is not large enough to cause the DBTT shift.

Download or read book Effects of Radiation on Structural Metals written by Books on Demand and published by ASTM International. This book was released on 1967 with total page 723 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Neutron Irradiation and Temperature on High Strain Rate Behaviour of Reactor Pressure Vessel Steel written by Z. Bílek and published by . This book was released on 1982 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes the results of an investigation of the influence of neutron irradiation on mechanical properties of a reactor pressure vessel steel at high strain rates ?? ? (103 to 104)s-1 produced by means of the Hopkinson split pressure bar technique (HSPBT). Our steel with chemical composition 0.18% C, 1.22% Mn, 0.012% P, 0.016% S, 0.17% Cr, 0.33% Ni, 0.055% Al, 0.028% Ti was irradiated by fast neutrons to an exposure of 1.35 . 1023 (n)m-2. The extensive dynamic measurements performed in the temperature range of (90 + 573) °K are analysed in terms of state equation for viscoplastic flow. It is shown that neutron irradiation shifts the transition between thermally activated and viscous dislocation damping mechanism of plastic deformation to the higher strain rates. Particular attention is paid to the comparison of the influence of neutron irradiation and strain aging.

Download or read book A SURVEY OF THE EFFECTS OF NEUTRON IRRADIATION ON THE IMPACT AND OTHER MECHANICAL PROPERTIES OF PRESSURE VESSEL STEELS FOR THE SM 2 REACTOR written by and published by . This book was released on 1960 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A literature survey on the effects of neutron irradiation on impact and other mechanical properties of both ferritic steels and austenitic stainless steels is presented. The materials studied included carbon and low alloy steels such as: ASTM A-212B, ASTM A-201, ASTM A-301B (CR-Mo), ASTM A-106 (coarse and fine grained), ASTM A-285, ASTM A-302B (Mn-Mo), ASTM A-353, ASTM A-203, Grade D, E-7016 carbon steel weld metal, USS Carilloy T-1, HY-65, and HY-80. Types 304 and 347 stainless steels were investigated as representative austenitic materials which might be used in pressure vessel construction. An evaluation was made of the irradiation induced changes in the mechancal properties of the above materials. The ferritic steels were evaluated primarily on the basis of increases in transition temperature due to irradiation and decreases in the amount of maximum energy absorbed prior to ductile failure. Factors such as industrial experience, changes in other mechanical properties, and the susceptibility of these materials to temper embrittlement were considered. Austenitic stainless steels were evaluated on the basis of post-irradiation and low temperature impact strength and on irradiation induced changes in other mechanical properties. It is concluded that austenitic stainless steels are capable of resisting harmful property damage at integrated neutron fluxes> 1 Mev of at least 1 to 2 x 10/sup 21/ nvt. Most carbon or low alloy steels with the exception of ASTM A-212B, were subject to severe property damage at exposures in excess of 1 x 10/sup 19/ nvt. With the application of special reactor operating procedures, it was determined that ASTM A-212B will be satisfactory at integrated neutron fluxes up to 5 x 10/sup 19/ nvt. (auth).

Download or read book Effects of Irradiation in Iron and Steels written by B. L. Eyre and published by . This book was released on 1965 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of irradiation under a variety of neutron flux and temperature conditions on the transition temperature of a low-carbon, low-alloy steel containing 0.0036 weight per cent boron have been investigated. This steel exhibits greater embrittlement than nominally boron-free steels irradiated under similar conditions ; the differences in behavior have been analyzed in terms of the additional displaced atoms and clusters of defects respectively produced in the iron lattice by the energetic products of the B10 (n, ?) Li7 reaction in the boron steel.

Download or read book The Effect of Neutron Flux on Radiation Induced Embrittlement in Reactor Pressure Vessel Steels written by RE. Stoller and published by . This book was released on 2004 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of neutron flux level is a longstanding concern for determining the applicability of test reactor data or high lead-factor surveillance data to the prediction of embrittlement in commercial reactor pressure vessels (RPV). However, as operating reactors reach higher fluences, the question of flux effects is becoming increasingly relevant for situations such as embrittlement attenuation through the (RPV) and the comparison of boiling and pressurized reactor RPVs. In spite of its technological importance and extensive experimental and theoretical investigation, the issue of neutron flux effects on radiation-induced embrittlement in RPV steels remains unresolved. For neutron fluxes much greater than RPV operating conditions (>100 times higher), a regime exists in which the effects of flux are well defined experimentally and are well predicted by current models. These same models predict that the effect of flux should be relatively weak for values near those obtained in commercial RPVs, but may increase at lower fluxes. However, it is difficult to obtain sufficient data at low to intermediate fluxes to unambiguously determine the effects of flux since the time required to reach the desired fluences is necessarily long. In order to demonstrate the potential effects of flux on RPV embrittlement, and to help interpret the available experiments, a kinetic embrittlement model has been used in an analysis of the primary variables involved. The results of the analysis are consistent with a modest effect of flux on embrittlement for fluxes near those typical of commercial RPVs.

Download or read book The Effect of Fast Neutron Irradiation on the Mechanical Properties of Some Quenched and Tempered Steels written by RR. Hosbons and published by . This book was released on 1970 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: Specimens from seven heats of AISI 403, five heats of A542, and one heat of AISI 431 were irradiated at 300 C in pressurized water to find the effect of chemical composition on their irradiated properties. The change in ductile-brittle transition temperature ?T after the maximum integrated fast neutron flux of 1x1020 n/cm2, E > 1 MeV, was similar for these steels. Some of the heats were also tested after an integrated flux of 6x1019 n/cm2, E > 1 MeV, and the results showed that the latter flux caused saturation of damage in AISI 403. The total impurity concentration of AISI 403 appeared to control the size of ?T at saturation, but there was no such correlation in the other steels. Obversely, the nitrogen concentration of A542 did affect its change of transition temperature for a given flux; a titanium concentration of 0.1 weight percent increased the unirradiated transition temperature but not ?T. AISI 431 is unsuitable for use at 300 C as it is thermally embrittled. Although the ?T values for AISI 403 and A542 were the same, the latter had a lower initial transition temperature.