Download or read book Fatigue Life and Crack Growth Predictions of Irradiated Stainless Steels written by Robert William Fuller and published by . This book was released on 2018 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of prominent issues related to failures in nuclear power components is attributed to material degradation due the aggressive environment conditions, and mechanical stresses. For instance, reactor core support components, such as fuel claddings, are under prolonged exposure to an intense neutron field from the fission of fuel and operate at elevated temperature under fatigue loadings caused by start-up, shut-down, and unscheduled emergency shut-down. Additionally, exposure to high-fluence neutron radiation can lead to microscopic defects that result in material hardening and embrittlement, which significantly affects the physical and mechanical properties of the materials, resulting in further reduction in fatigue life of reactor structural components. The effects of fatigue damage on material deterioration can be further exacerbated by the presence of thermal loading, hold-time, and high-temperature water coolant environments. In this study, uniaxial fatigue models were used to predict fatigue behavior based only on simple monotonic properties including ultimate tensile strength and Brinell hardness. Two existing models, the Bäumel-Seeger uniform material law and the Roessle-Fatemi hardness method, were employed and extended to include the effects of test temperature, neutron irradiation fluence, irradiation-induced helium and irradiation-induced swellings on fatigue life of austenitic stainless steels. Furthermore, a methodology to estimate fatigue crack length using a strip-yield based model is presented. This methodology is also extended to address the effect of creep deformation in a presence of hold- times, and expanded to include the effects of irradiation and water environment. Reasonable fatigue life predictions and crack growth estimations are obtained for irradiated austenitic stainless steels types 304, 304L, and 316, when compared to the experimental data available in the literature. Lastly, a failure analysis methodology of a mixer unit shaft made of AISI 304 stainless steel is also presented using a conventional 14-step failure analysis approach. The primary mode of failure is identified to be intergranular stress cracking at the heat affected zones. A means of circumventing this type of failure in the future is presented.
Download or read book Effect of Neutron Irradiation on Fatigue Crack Propagation in Types 304 and 316 Stainless Steels at High Temperatures written by P. Shahinian and published by . This book was released on 1973 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: Resistance to fatigue crack propagation of pre- and postirradiation AISI Types 304 and 316 stainless steels was determined at 800 and 1100 F (427 and 593 C) using the fracture mechanics approach. The effect of irradiation on fatigue resistance was dependent upon test temperature and irradiation conditions. In general, irradiation degraded fatigue resistance at 1100 F (593 C) but at 800 F (427 C) enhancement as well was observed. In both steels irradiated in a thermal reactor to a fluence of 1.8 x 1021 n/cm2 >0.1 MeV, fatigue crack growth rates at 800 F (427 C) were lower than in the unirradiated steels for a given stress intensity factor range (?K). However, at 1100 F (593 C) the effect was reversed and crack growth rates were higher in the irradiated steels. Irradiation in a fast reactor to a fluence of ~1.2 x 1022 n/cm2 >0.1 MeV caused fatigue crack growth rates at 800 F (427 C) to increase at low values of ?K and decrease at high values of ?K. At 1100 F (593 C) the crack growth rates in the irradiated steel were either the same as or higher than in the unirradiated steel. The influence of irradiation on fatigue life generally reflected the effect observed on crack growth rate.
Download or read book Automated Test Methods for Fatigue Crack Growth and Fracture Toughness Tests on Irradiated Stainless Steels at High Temperature written by BAJ Schaap and published by . This book was released on 1985 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: An automated system for fatigue crack growth and fracture toughness measurements has been developed for irradiated stainless steels tested at temperatures up to 925 K. The system, including a microcomputer, is based on the d-c potential-drop technique for crack extension measurements. Specimens of the compact-tension type are used for the experiments. A description is given of the potential-drop method and the automated data acquisition system. The method of collecting N-a data pairs is given as well as the calculation and analysis of the fatigue crack growth rate (da/dN) and stress-intensity factor (?K). The measurement of load, deflection, and crack extension data to determine the J-versus-?a curves is also discussed.
Download or read book Fatigue Crack Propagation in Fast Neutron Irradiated Stainless Steels and Welds written by P. Shahinian and published by . This book was released on 1975 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Neutron irradiation to a fluence of 1.2 x 1022 neutrons (n)/cm2, > 0.1 MeV caused a small decrease in the resistance to fatigue crack propagation of Types 308 and 316 submerged-arc weld metals at 800 and 1100°F (427 and 593°C). Nevertheless, the postirradiation fatigue resistances of the weld metals were generally comparable to those of the corresponding base metal. Fatigue crack growth in Types 304 and 316 base metals were also affected by irradiation; the effect was dependent on the stress intensity factor and temperature. Although resistance to crack growth of cold-worked (25 percent) Type 304 stainless steel was only slightly reduced at 800°F by irradiation, the resistance at 1100°F was reduced markedly.
Download or read book Fatigue Crack Growth and Fracture Toughness Properties of Low Fluence Neutron Irradiated Type 316 and Type 304 Stainless Steels written by MI. De Vries and published by . This book was released on 1987 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: Small compact-tension specimens of Type 316 plate and Type 304 forging have been irradiated in the High Flux Reactor (HFR) at Petten, The Netherlands, up to a fluence level of 2 x 1024 neutrons (n) . m-2 (E > 0.1 MeV) at 573 K. Post-irradiation fatigue crack propagation tests and J-integral fracture toughness tests have been performed at the irradiation temperature. Additional tests were made at the higher temperatures of 723 and 823 K.
Download or read book Fatigue Crack Growth Characteristics of Several Austenitic Stainless Steels at High Temperature written by P. Shahinian and published by . This book was released on 1973 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: The resistance to fatigue crack growth of annealed stainless steels, Types 304, 316, 321, and 348, was determined at 77, 800, and 1100 F (25, 427, and 593 C). Crack growth rates were related to the stress intensity factor range (?K). With increase in temperature the rate of crack growth for a given (?K) increased. At room temperature the four steels had the same resistance to crack growth. However, at high temperatures crack growth became sensitive to the differences in composition and properties among the steels. At 1100 F (593 C), Type 348 steel had the greatest resistance to crack growth and Type 316 the lowest resistance. As a result, fatigue life was 3.4 times longer for Type 348 steel over Type 316 steel at this temperature. The characteristics of high-temperature fatigue crack growth were examined.
Download or read book Crack Growth Rate and Fracture Toughness Tests on Irradiated Cast Stainless Steels written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Crack Growth Rate and Fracture Toughness Tests on Irradiated Cast Stainless Steels written by Y. Chen and published by . This book was released on 2015 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fracture Toughness and Crack Growth Rates of Irradiated Austenitic Stainless Steels Nureg cr 6826 U s Nuclear Regulatory Commission 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 Irradiation effects on fatigue crack propagation in austenitic stainless steels written by D. J. Michell and published by . This book was released on 1977 with total page 22 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Hold Time and Frequency on the Fatigue Crack Growth Rate of Irradiated Cold Worked Type 316 Stainless Steel written by M. Adachi and published by . This book was released on 1992 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue crack growth rates in an irradiated 316 stainless steel were obtained at a load cycling frequency of 0.8 Hz with hold times of 1, 10, and 50 s and at 60 Hz at test temperatures ranging from 298 to 1023 K. Specimens were prepared from wrapper tube material, which was irradiated to a fluence level of 4 x 1026 n/m2 (E ? 0.1 MeV) at 683 K in a fast breeder reactor (JOYO).
Download or read book Fatigue Crack Growth Analysis of Stainless Steel Under Mode 1 written by Ahmad Azam Azizan Azlan and published by . This book was released on 2010 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stainless steel is widely used in the industries nowadays due to their good properties of resistance to corrosion and rust. Due to its application in many industries, an analysis of fatigue crack growth was carried out to study the effect of stress ratio. The study of fatigue crack growth is important since fatigue has become a critical issue in industries that plague any structures that is subjected to cyclic and variable loading. A necessary analysis of fatigue crack growth need to be done to study the behaviour of fatigue crack growth. The effect of stress ratio on fatigue crack growth can affect the behavior of fatigue crack growth. In the project, three different stress ratios were used to investigate the effect of stress ratio towards crack growth. As the stress ratio increase, the stress intensity threshold and fracture toughness will decrease. This shows that an increasing stress ratio will lead to material failure. This happens when the stress intensity factor has entered the critical region where it exceeds the fracture toughness value. To remain the material unbroken or fail, the stress intensity factor value must not exceed the value of stress intensity threshold where below the stress intensity threshold value, the material remains stable. An analysis of fatigue crack growth was done using MSC software where the stress analysis is done using MSC PATRAN and MSC NASTRAN. After the results of stress analysis were obtained, the analysis of fatigue crack growth with different stress ratio was done using MSC FATIGUE software. Life prediction of the material is determined using Modified Paris Law equation of Fracture Mechanics. At certain level of stresses, below the endurance limit of the material, the effect of stress ratio does not affecting the life of the material. This is because the stress is not big enough to break the material.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Crack Growth Rates of Irradiated Austenitic Stainless Steel Weld Heat Affected Zone in BWR Environments written by Omesh K. Chopra and published by . This book was released on 2006 with total page 57 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1975-04 with total page 1082 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fatigue Crack Propagation by Channel Fracture in Irradiated 316 Stainless Steel written by S. Jitsukawa and published by . This book was released on 1996 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue crack growth rates (da/dN)in an irradiated cold worked 316 stainless steel were obtained at temperatures of 298, 573 and 673 K. Specimens were prepared from a duct material, which irradiated at 683 K to 20 displacements per atom in an experimental fast breeder reactor.
Download or read book Crack Growth Rates and Fracture Toughness of Irradiated Austenitic Stainless Steels in BWR Environments written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In light water reactors, austenitic stainless steels (SSs) are used extensively as structural alloys in reactor core internal components because of their high strength, ductility, and fracture toughness. However, exposure to high levels of neutron irradiation for extended periods degrades the fracture properties of these steels by changing the material microstructure (e.g., radiation hardening) and microchemistry (e.g., radiation-induced segregation). Experimental data are presented on the fracture toughness and crack growth rates (CGRs) of wrought and cast austenitic SSs, including weld heat-affected-zone materials, that were irradiated to fluence levels as high as (almost equal to) 2x 1021 n/cm2 (E> 1 MeV) ((almost equal to) 3 dpa) in a light water reactor at 288-300 C. The results are compared with the data available in the literature. The effects of material composition, irradiation dose, and water chemistry on CGRs under cyclic and stress corrosion cracking conditions were determined. A superposition model was used to represent the cyclic CGRs of austenitic SSs. The effects of neutron irradiation on the fracture toughness of these steels, as well as the effects of material and irradiation conditions and test temperature, have been evaluated. A fracture toughness trend curve that bounds the existing data has been defined. The synergistic effects of thermal and radiation embrittlement of cast austenitic SS internal components have also been evaluated.
