Download or read book Evaluation of Effects of LWR Coolant Environments on Fatigue Life of Carbon and Low Alloy Steels written by OK. Chopra and published by . This book was released on 1997 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ASME Boiler and Pressure Vessel Code provides rules for the construction of nuclear power plant components. Figure I-90 of Appendix I to Section III of the Code specifies fatigue design curves for structural materials. However, the effects of light water reactor (LWR) coolant environments are not explicitly addressed by the Code design curves. Recent test data indicate a significant decrease in fatigue life of carbon and low-alloy steels in LWR environments when five conditions are satisfied simultaneously, viz., applied strain range, temperature, dissolved oxygen in the water, and sulfur content of the steel are above a minimum threshold level, and the loading strain rate is below a threshold value. Only a moderate decrease in fatigue life is observed when any one of these conditions is not satisfied. This paper summarizes available data on the effects of various material and loading variables such as steel type, dissolved oxygen level, strain range, strain rate, and sulfur content on the fatigue life of carbon and low-alloy steels. The data have been analyzed to define the threshold values of the five critical parameters. Methods for estimating fatigue lives under actual loading histories are discussed.
Download or read book Effects of LWR Coolant Environments on Fatigue S N Curves for Carbon and Low alloy Steels written by and published by . This book was released on 1996 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ASME Boiler and Pressure Vessel Code provides rules for the construction of nuclear power plant components. Figure I-90 of Appendix I to Section III of the Code specifies fatigue design curves for structural materials. However, the effects of light water reactor (LWR) coolant environments are not explicitly addressed by the Code design curves. Recent test data indicate significant decreases in fatigue lives of carbon and low-alloy steels in LWR environments when five conditions are satisfied simultaneously: applied strain range, temperature, dissolved oxygen in the water, and S content of the steel are above minimum threshold levels, and loading strain rate is below a threshold value. Only moderate decrease in fatigue life is observed when any one of these conditions is not satisfied. This paper presents several methods that have been proposed for evaluating the effects of LWR coolant environments on fatigue S-N curves for carbon and low-alloy steels. Estimations of fatigue lives under actual loading histories are discussed.
Download or read book Effects of LWR Coolant Environments on Fatigue Lives of Austenitic Stainless Steels written by and published by . This book was released on 1997 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ASME Boiler and Pressure Vessel Code fatigue design curves for structural materials do not explicitly address the effects of reactor coolant environments on fatigue life. Recent test data indicate a significant decrease in fatigue life of pressure vessel and piping materials in light water reactor (LWR) environments. Fatigue tests have been conducted on Types 304 and 316NG stainless steel in air and LWR environments to evaluate the effects of various material and loading variables, e.g., steel type, strain rate, dissolved oxygen (DO) in water, and strain range, on fatigue lives of these steels. The results confirm the significant decrease in fatigue life in water. The environmentally assisted decrease in fatigue life depends both on strain rate and DO content in water. A decrease in strain rate from 0.4 to 0.004%/s decreases fatigue life by a factor of ≈ 8. However, unlike carbon and low-alloy steels, environmental effects are more pronounced in low-DO than in high-DO water. At ≈ 0.004%/s strain rate, reduction in fatigue life in water containing
Download or read book Methods for Incorporating Effects of LWR Coolant Environment Into ASME Code Fatigue Evaluations written by and published by . This book was released on 1999 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ASME Boiler and Pressure Vessel Code provides rules for the construction of nuclear power plant components. Appendix I to Section HI of the Code specifies design fatigue curves for structural materials. However, the effects of light water reactor (LWR) coolant environments are not explicitly addressed by the Code design curves. Recent test data illustrate potentially significant effects of LWR environments on the fatigue resistance of carbon and low-alloy steels and austenitic stainless steels (SSs). Under certain loading and environmental conditions, fatigue lives of carbon and low-alloy steels can be a factor of (almost equal to)70 lower in an LWR environment than in air. These results raise the issue of whether the design fatigue curves in Section III are appropriate for the intended purpose. This paper presents the two methods that have been proposed for incorporating the effects of LWR coolant environments into the ASME Code fatigue evaluations. The mechanisms of fatigue crack initiation in carbon and low-alloy steels and austenitic SSs in LWR environments are discussed.
Download or read book Effects of LWR Environments on Fatigue Life of Carbon and Low alloy Steels written by and published by . This book was released on 1995 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: SME Boiler and Pressure Vessel Code provides construction of nuclear power plant components. Figure I-90 Appendix I to Section III of the Code specifies fatigue design curves for structural materials. While effects of environments are not explicitly addressed by the design curves, test data suggest that the Code fatigue curves may not always be adequate in coolant environments. This paper reports the results of recent fatigue tests that examine the effects of steel type, strain rate, dissolved oxygen level, strain range, loading waveform, and surface morphology on the fatigue life of A 106-Gr B carbon steel and A533-Gr B low-alloy steel in water.
Download or read book Methods for Incorporating the Effects of LWR Coolant Environments in Pressure Vessel and Piping Fatigue Evaluations written by and published by . This book was released on 2002 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper summarizes the work performed at Argonne National Laboratory on the fatigue of piping and pressure vessel steels in the coolant environments of light water reactors. The existing fatigue strain vs. life ({var_epsilon}-N) data were evaluated to establish the effects of various material and loading variables, such as steel type, strain range, strain rate, temperature, and dissolved-oxygen level in water, on the fatigue lives of these steels. Statistical models are presented for estimating the fatigue {var_epsilon}-N curves for carbon and low-alloy steels and austenitic stainless steels as a function of material, loading, and environment variables. Case studies of fatigue failures in nuclear power plants are presented, and the contribution of environmental effects to crack initiation is discussed. Methods for incorporating environmental effects into the ASME Code fatigue evaluations are discussed. Data available in the literature have been reviewed to evaluate the possible conservatism in the existing fatigue design curves of the ASME Code.
Download or read book Effects of LWR Coolant Environments on Fatigue Design Curves of Carbon and Low Alloy Steels written by O. K. Chopra and published by . This book was released on 1998-03-01 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Material and Loading Variables on Fatigue Life of Carbon and Low alloy Steels in LWR Environments written by and published by . This book was released on 1995 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ASME Boiler and Pressure Vessel Code provides rules for the construction of nuclear power plant components. Section III of the Code specifies fatigue design curves for structural materials. While effects of reactor coolant environments are not explicitly addressed by the design curves, test data suggest that the Code fatigue curves may not always be adequate in coolant environments. This paper reports the results of recent fatigue tests that examine the effects of steel type, strain rate, dissolved oxygen level, strain range, loading waveform, and surface morphology on the fatigue life of A106-Gr B carbon steel and A533-Gr B low-alloy steel in water.
Download or read book Fatigue of Carbon and Low alloy Steels in LWR Environments written by and published by . This book was released on 1993 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue tests have been conducted on A106-Gr B carbon steel and A533-Gr B low-alloy steel to evaluate the effects of an oxygenated-water environment on the fatigue life of these steels. For both steels, environmental effects are modest in PWR water at all strain rates. Fatigue data in oxygenated water confirm the strong dependence of fatigue life on dissolved oxygen (DO) and strain rate. The effect of strain rate on fatigue life saturates at some low value, e.g., between 0.0004 and 0.001%/s in oxygenated water with (approximately)0.8 ppm DO. The data suggest that the saturation value of strain rate may vary with DO and sulfur content of the steel. Although the cyclic stress-strain and cyclic-hardening behavior of carbon and low-alloy steels is distinctly different, the degradation of fatigue life of these two steels with comparable sulfur levels is similar. The carbon steel exhibits pronounced dynamic strain aging, whereas strain-aging effects are modest in the low-alloy steel. Environmental effects on nucleation of fatigue crack have also been investigated. The results suggest that the high-temperature oxygenated water has little or no effect on crack nucleation.
Download or read book Fatigue Assessment in Light Water Reactors for Long Term Operation written by IAEA and published by International Atomic Energy Agency. This book was released on 2023-04-27 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue is a major element in time limited ageing analysis for long term operation of nuclear power plants (NPPs). It is important to understand how cracks occur and grow as a result of fatigue, and then assess fatigue failure. In the design and operating phase of NPPs, it is essential to consider the concurrent loadings associated with the design transients, thermal stratification, seismically induced stress cycles, and all relevant loads due to the various operational modes. After repeated cyclic loading, crack initiation can occur at the most highly affected locations if sufficient localized micro-structural damage has accumulated. This publication provides practical guidelines on how to identify and manage fatigue issues in NPPs. It explains the mechanism of fatigue, identifies which elements are the major contributors, and details how fatigue can be minimized in the design phase for new NPPs.
Download or read book International Encounter on the Philosophy of Language 1 written by and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fatigue Crack Initiation in Carbon and Low alloy Steels in Light Water Reactor Environments written by and published by . This book was released on 1998 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt: Section 111 of the ASME Boiler and Pressure Vessel Code specifies fatigue design curves for structural materials. The effects of reactor coolant environments are not explicitly addressed by the Code design curves. Recent test data illustrate potentially significant effects of light water reactor (LWR) coolant environments on the fatigue resistance of carbon and low-alloy steels. Under certain loading and environmental conditions, fatigue lives of test specimens may be shorter than those in air by a factor of H"0. The crack initiation and crack growth characteristics of carbon and low-alloy steels in LWR environments are presented. Decreases in fatigue life of these steels in high-dissolved-oxygen water are caused primarily by the effect of environment on growth of short cracks
Download or read book Proceedings of the 15th International Conference on Environmental Degradation of Materials in Nuclear Power Systems Water Reactors written by Gabriell Ilevbare and published by Springer. This book was released on 2017-07-17 with total page 2354 pages. Available in PDF, EPUB and Kindle. Book excerpt: This 15th Edition of the International Conference on Materials Degradation in Light Water Reactors focuses on subject areas critical to the safe and efficient running of nuclear reactor systems through the exchange and discussion of reseach results as well as field operating and management experience.
Download or read book Effects of Temperature and Dissolved Oxygen Contents on Fatigue Lives of Carbon and Low Alloy Steels in LWR Water Environments written by Y. Asada and published by . This book was released on 1997 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to modify the fatigue design method for pressure vessel components of light water rcactors(LWRs), strain controlled fatigue tests were carried out under various environmental conditions, and the effects of temperature and dissolved oxygen (DO) contents on fatigue lives of carbon steel in LWR-simulated water environments were evaluated and analyzed.
Download or read book Effects of the Environment on the Initiation of Crack Growth written by William Alan Van der Sluys and published by ASTM International. This book was released on 1997 with total page 304 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fatigue and Fracture 1997 written by Hardayal S. Mehta and published by . This book was released on 1997 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt: Forty-five papers presented at the July 1997 conference illustrate the application of fatigue and fracture mechanics techniques to assess the structural integrity of a wide variety of pressure vessels and piping components. Topics include piping and components; leak-before-break analyses; environmen
