Download or read book Crack Initiation and Crack Growth Behavior of Carbon and Low alloy Steels written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Section III of the ASME Boiler and Pressure Vessel Code specifies fatigue design curves for structural materials. These curves were based on tests of smooth polished specimens at room temperature in air. The effects of reactor coolant environments are not explicitly addressed by the Code design curves, but recent test data illustrate potentially significant effects of 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 a factor of[approx]70 shorter than in air. Results of fatigue tests that examine the influence of reactor environment on crack imitation and crack growth of carbon and low-alloy steels are presented. Crack lengths as a function of fatigue cycles were determined in air by a surface replication technique, and in water by block loading that leaves marks on the fracture surface. Decreases in fatigue life of low-alloy steels in high-dissolved-oxygen (DO) water are primarily caused by the effects of environment during early stages of fatigue damage, i.e., growth of short cracks100[micro]m in depth. For crack sizes of100[micro]m, crack growth rates in high-DO water are higher than in air by one order of magnitude. The effects of LWR environments on growth of short cracks are discussed.

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 The Effect of Aqueous Environments Upon the Initiation and Propagation of Fatigue Cracks in Low alloy Steels written by and published by . This book was released on 1996 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of elevated temperature aqueous environments upon the initiation and propagation of fatigue cracks in low-alloy steels is discussed in terms of the several parameters which influence such behavior. These parameters include water chemistry, impurities within the steels themselves, as well as factors such as the water flow rate, loading waveform and loading rates. Some of these parameters have similar effects upon both crack initiation and propagation, while others exhibit different effects in the two stages of cracking. In the case of environmentally-assisted crack (EAC) growth, the most important impurities within the steel are metallurgical sulfide inclusions which dissolve upon contact with the water. A ''critical'' concentration of sulfide ions at the crack tip can then induce environmentally-assisted cracking which proceeds at significantly increased crack growth rates over those observed in air. The occurrence, or non-occurrence, of EAC is governed by the mass-transport of sulfide ions to and from the crack-tip region, and the mass-transport is discussed in terms of diffusion, ion migration, and convection induced within the crack enclave. Examples are given of convective mass-transport within the crack enclave resulting from external free stream flow. The initiation of fatigue cracks in elevated temperature aqueous environments, as measured by the S-N fatigue lifetimes, is also strongly influenced by the parameters identified above. The influence of sulfide inclusions does not appear to be as strong on the crack initiation process as it is on crack propagation. The oxygen content of the environment appears to be the dominant factor, although loading frequency (strain rate) and temperature are also important factors.

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 Variable Amplitude Fatigue Crack Initiation and Growth of Five Carbon Or Low Alloy Cast Steels at Room and Low Climatic Temperatures written by A. Fatemi and published by . This book was released on 1985 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Five common cast steels were subjected to SAE transmission history at room temperature and three low climatic temperatures using an as-drilled keyhole notched compact specimen. The three low temperatures were -34, -45, and -60°C. These temperatures were both above and below nil ductility transition temperatures. Three fatigue criteria were specifically monitored: crack initiation defined by the first visible surface crack ?a equal to 0.25 mm, ?a equal to 2.5 mm, and final fracture. All low-temperature total fatigue lives were equal to or better than at room temperature for four of the five cast steels. All steels exhibited crack initiation lives at low temperatures equal to or better than at room temperature. Fatigue crack growth life tended to increase as the temperature was lowered, and then this trend reversed. Scanning electron fractographic analysis showed all ductile type fatigue crack growth mechanisms above or below the nil ductility transition temperature.

Download or read book Low Cycle Fatigue Behavior and Crack Propagation in Some Steels written by Saurindranath Majumdar and published by . This book was released on 1974 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: In a previous report, a fatigue crack propagation model was analyzed by considering fatigue crack propagation as a sequence of fatigue crack initiation events. This permitted correlation to be made between the fatigue crack growth resistance and low cycle fatigue properties of metals. Four steels were tested for low cycle fatigue behavior at the University of Illinois. Good correlation was obtained between the theoretically predicted crack propagation rate based on the measured low cycle fatigue properties of the four metals and experimentally observed crack propagation rates that were reported in the literature. Further, good estimates of crack propagation rates can be obtained on the basis of static tensile properties of the metals alone where cyclic properties are not available. (Author).

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 Temperature and Environmentally Assisted Cracking in Low Alloy Steel written by T. A. Auten and published by . This book was released on 1995 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Stress intensity Factor Equations for Cracks in Three dimensional Finite Bodies Subjected to Tension and Bending Loads written by J. C. Newman and published by . This book was released on 1984 with total page 98 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Crack Initiation in a High Strength Low Alloy Steel written by BL. Braglia and published by . This book was released on 1979 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fatigue crack initiation behavior of a high-strength low-alloy steel, VAN-80, has been investigated. Crack initiation was defined, for the purposes of the study, as the existence of a 0.25-mm long crack on either surface of a modified compact tension specimen.

Download or read book Gaseous Environment Fatigue Crack Propagation Behavior of a Low Alloy Steel written by JK. Donald and published by . This book was released on 1989 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue crack growth behavior of 4340 steel was investigated in gaseous environments: laboratory air, hydrogen, and helium. No significant effect of specimen orientation on the rates of fatigue crack propagation was observed. In each environment, increasing load ratio decreased the threshold stress-intensity range (?Kth). The effect of load ratio on ?Kth in the air environment was, however, much more significant than that in wet hydrogen and dry environments (dry hydrogen and dry helium). At low load ratios (? 0.5), the values of ?Kth in the air environment were larger than those in dry environments. The ?Kth values in wet hydrogen were in between those in air and dry environments. At a high load ratio of 0.8, ?Kth was, however, insensitive to test environment.

Download or read book Influence of Overload and Temperature on Stress Corrosion Crack Growth Behavior in a Low Alloy Steel written by SK. Putatunda and published by . This book was released on 1990 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: An investigation was carried out to examine the influence of temperature and overload plastic zone size on stress corrosion crack (SCC) growth behavior in a low-alloy steel. Compact tension specimens with TL orientation prepared from SAE 4140 steel in hardened and tempered condition were used. Two pertinent variable conditions were chosen: (1) cold deionized water at 23°C and (2) hot deionized water at 80°C. The specimens were precracked in fatigue and then overloaded to various extent (5, 10, 25, and 50%). The SCC behavior of these specimens was studied, keeping them submerged in hot and cold deionized water.

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 Een nyeu evaluacie boecxken gheordineert van weghen onser ghenadichs heeren des Keysers by den generaels vander munten vanden gouden ende silveren ghevalueerde penningen ende oock dye weerde van allen verboden gouden ende silveren penninghen dye noyt geprent geweest en is navolghende dassayen biden generaels daer af ghemaect int jaer MCCCCC ende XXVI written by and published by . This book was released on 1526 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Creep Crack Growth Behavior of Carbon Steels written by Ashok Saxena and published by . This book was released on 1991 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effect of Potential Upon the High temperature Fatigue Crack Growth Response of Low alloy Steels Part 1 written by and published by . This book was released on 1997 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: Corrosion-fatigue crack propagation experiments were conducted on several low-alloy steels in elevated temperature aqueous environments, and experimental parameters included temperature, sulfur content of the steel, applied potential level, and dissolved hydrogen (and in one case, dissolved oxygen) concentration in the water. Specimen potentials were controlled potentiostatically, and the observation (or non-observation) of accelerated fatigue crack growth rates was a complex function of the above parameters. Electrochemical results and the postulated explanation for the complex behavior are given in Part II.

Download or read book Creep Embrittlement Susceptibility and Creep Crack Growth Behavior in Low Alloy Steels written by S. Konosu and published by . This book was released on 1988 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: Creep embrittlement at 550C in the coarse grain region of the heat-affected zone (HAZ) of 1Cr-Mo steel was investigated. As a result, the effects of impurity elements and postweld heat treatment (PWHT) on such creep embrittlement and crack growth has been clarified. Creep embrittlement is caused by the nucleation of intergranular cavities at the prioraustenite grain boundary of the HAZ. Likewise, creep crack propagation is caused by the nucleation and linking up of intergranular cavities which precede the further growth of the main crack. The remaining creep crack growth life was predicted by a computer simulation of an actual reactor.