Download or read book Empirical Analyses of Effects of the Heat Affected Zone and Post Weld Heat Treatment on Irradiation Embrittlement of Reactor Pressure Vessel Steel written by Greg Troyer and published by . This book was released on 2014 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: An empirical data mining approach was employed to separate the effects of weld thermal cycles in the Heat Affected Zone (HAZ) and Post Weld Heat Treatment (PWHT) on Transition Temperature Shift (TTS) from other variables, using unirradiated and irradiated Charpy test data obtained from US RPV surveillance program results. HAZ data, which tend to have greater scatter due to microstructural variation in the HAZ, are separated into "high scatter" and "low scatter" categories to assess the effect of scatter on TTS trends. In general, the TTS behavior of the HAZ is comparable to the non-HAZ. However, the forging HAZ TTS diverges from the non-HAZ TTS as a function of copper content. This trend is also observed in the plate HAZ when looking at plate HAZ datasets with copper content and PWHT times less than forging copper content (

Download or read book Survey of postirradiation heat treatment as a means to mitigate radiation embrittlement of reactor vessel steels written by J. R. Hawthorne and published by . This book was released on 1979 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Radiation Embrittlement of Nuclear Reactor Pressure Vessel Steels written by Lendell E. Steele and published by ASTM International. This book was released on 1986 with total page 303 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigation of Temper Embrittlement in Reactor Pressure Vessel Steels Following Thermal Aging Irradiation and Thermal Annealing written by MA. Sokolov and published by . This book was released on 2001 with total page 27 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Heavy-Section Steel Irradiation Program at Oak Ridge National Laboratory includes a task to investigate the propensity for temper embrittlement in coarse grain regions of heat-affected zones in prototypic reactor pressure vessel (RPV) steel weldments as a consequence of irradiation and thermal annealing. For the present studies, five prototypic RPV steels with specifications of A302 grade B, A302 grade B (modified), A533 grade B class 1, and A508 class 2 were given two different austenitization treatments and various thermal aging treatments. Thermal aging treatments were conducted at 399, 425, 454 and 490°C for times of 168 and 2000 h. Charpy V-notch impact toughness vs temperature curves were developed for each condition with ductile-brittle transition temperatures used as the basis for comparing the effects of the various heat treatments. Very high austenitization heat treatment produced extremely large grains which exhibited a very high propensity for temper embrittlement following thermal aging. Intergranular fracture was the predominant mode of failure in many of the materials and Auger analysis confirmed significant segregation of phosphorus at the grain boundaries. Lower temperature austenitization treatment performed in a super Gleeble to simulate prototypic coarse grain microstructures in submerged-arc weldments produced the expected grain size with varying propensity for temper embrittlement dependent on the material as well as on the thermal aging temperature and time. Although the lower temperature treatment resulted in decreased propensity for temper embrittlement, the results did provide motivation for the investigation of the potential for phosphorus segregation as a consequence of neutron irradiation and post-irradiation thermal annealing at 454°C. One of the A 302 grade B (modified) steels was given the Gleeble treatment, irradiated at 288°C to about 0.8 x 1019n/cm (>1 MeV) and given a thermal annealing treatment at 454°C for 168 h. Charpy impact testing was conducted on the material in both the irradiated and irradiated/annealed conditions, as well as in the as-received condition. The results show that, although the material exhibited a relatively small Charpy impact 41-J temperature shift, the heat-affected zone-simulated material did exhibit significant intergranular fracture in the post-irradiation annealed condition.

Download or read book Irradiation Embrittlement of Reactor Pressure Vessel Steels written by GE. Lucas and published by . This book was released on 1986 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: A model of irradiation embrittlement is described for predicting the 41-J Charpy V-notch temperature shifts (?T) as a function of metallurgical variables and neutron exposure conditions. This forecasting procedure combines semi-empirical physical models with statistical analyses of test and power reactor data, and calibration against data from fundamental experiments in which both mechanical property and microstructural changes are evaluated. The models are based on the evolution of a damage microstructure, which includes both copper precipitates and a radiation damage component enhanced by nickel. The precipitate volume is also increased by nickel and impurity phosphorus. Predicted hardening and shifts associated with these extended defects are based on empirically validated models. The model is able to self-consistently rationalize a wide array of microstructural and mechanical property data for commercial pressure vessel steels as well as model alloys.

Download or read book The effects of composition and heat treatment on hardening and embrittlement of reactor pressure vessel steels written by G. R. Odette and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Survey of Postirradiation Heat Treatment as a Means to Mitigate Radiation Embrittlement of Reactor Vessel Steels written by J. R. Hawthorne and published by . This book was released on 1979 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: Postirradiation heat treatment (annealing) is being investigated as a method for the alleviation of radiation embrittlement to reactor vessel steels. Objectives of this study were to identify those service and metallurgical variables which can affect annealing response, to report data comparisons available for qualification of suspected influences, and to survey experimental results from commercially produced reactor materials and duplicate materials from the laboratory. Twelve factors are identified as having potential for affecting the postirradiation heat treatment response of low-alloy pressure vessel steels. A tentative qualification of six factors as significant contributing variables is made on the basis of experimental comparisons. Of these, heat-treatment temperature was observed to exert the largest influence on the embrittlement relief by annealing. The evidence indicates that a 399C heat treatment, but not a 343C heat treatment, is a practical and effective method for reducing and controlling radiation embrittlement in reactor vessels.

Download or read book The Effects of Composition and Heat Treatment on Hardening and Embrittlement of Reactor Pressure Vessel Steels Nureg cr 6778 U s Nucl written by and published by . This book was released on 2003* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Heat Transfer Analysis of the LWR Pressure Vessel Steel Irradiation Capsules in the Oak Ridge Research Reactor pressure Vessel Benchmark Facility written by Ilana I. Siman-Tov and published by . This book was released on 1982 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Metals Abstracts written by and published by . This book was released on 1996 with total page 1622 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Temper Embrittlement Irradiation Induced Phosphorus Segregation and Implications for Post Irradiation Annealing of Reactor Pressure Vessels written by CA. English and published by . This book was released on 1999 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three steels designated JPB, JPC and JPG from the IAEA Phase 3 Programme containing two copper and phosphorus levels were pre- and post-irradiation Charpy and hardness tested in the as-received (AR), 1200°C/0.5h heat treated (HT) and heat treated and 450°C/2000h aged (HTA) conditions. The HT condition, was designed to simulate coarse grained heat-affected zones (HAZ's) and showed a marked sensitivity to thermal ageing in all three alloys. Embrittlement after thermal ageing was greater in the higher phosphorus alloys JPB and JPG. Charpy shifts due to thermal ageing of between 118 and 209°C were observed and accompanied by pronounced intergranular fracture, due to phosphorus segregation. The irradiation embrittlement response was complex. The low copper alloys, JPC and JPB, in the HT and HTA condition exhibited significant irradiation induced Charpy shift but very low or even negative hardness changes indicating non-hardening embrittlement. The higher copper alloy, JPG, also exhibited irradiation hardening in line with its copper content. Fractographic and microchemical studies indicated irradiation induced phosphorus segregation and a transition from cleavage to intergranular failure at grain boundary phosphorus concentrations above a critical level. The enhanced grain boundary phosphorus level increased with dose in agreement with a kinetic segregation model developed at Harwell.

Download or read book Metals Abstracts Index written by and published by . This book was released on 1983 with total page 894 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Heat Transfer Analysis of the Pressure Vessel Steel Irradiation Capsules in the Oak Ridge Research Reactor Pressure Vessel Benchmark Facility written by Ilana I. Siman-Tov and published by . This book was released on 1981 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effect of Irradiation on Weldability of ASTM A212 Grade B written by Wendell R. Hutchinson and published by . This book was released on 1956 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book INIS Atomindex written by and published by . This book was released on 1984 with total page 748 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Irradiation Effects in Reactor Pressure Vessel Steels written by CZ. Serpan and published by . This book was released on 1986 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The embrittling effect of neutron irradiation on reactor pressure vessel steel and welds has a significant impact on the regulation of reactors by the U.S. Nuclear Regulatory Commission (NRC). Because the NRC is concerned with the continuing integrity and safety of the reactor's primary system, the neutron-irradiation-induced loss of fracture toughness and ductility must be carefully documented, understood, and controlled to assure that despite such loss, there is always a sufficient reserve of toughness and ductility to preclude crack initiation and uncontrolled propagation in the unlikely event of an accident. Aspects of embrittlement important to the NRC, which are discussed herein, include prediction of the transition temperature and upper-shelf-energy levels at critical vessel locations for the setting of pressure-temperature limits, for analysis of accident loadings such as pressurized thermal shock, and for evaluation of flaws found in inspection. Also discussed are the use of embrittlement-related neutron dosimetry and evaluation of vessel annealing.