Download or read book Fatigue Crack Growth Behavior of Ferritic and Austenitic Steels at Elevated Temperatures written by M. Nani Babu and published by . This book was released on 2014 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: For the integrity assessment and damage-tolerant design of components operating at elevated temperatures under cyclic loading conditions, evaluation of fatigue crack growth (FCG) properties in the threshold and Paris regimes is important. The FCG behaviors of a modified 9Cr-1Mo steel (P91) and SS 316L(N) for applications in the prototype fast breeder reactor to be commissioned shortly at Kalpakkam, India have been studied extensively in our laboratory over a wide range of temperatures. Some aspects of high-temperature FCG observed in these investigations will be reviewed in this paper. It has been observed that for many engineering alloys, dynamic strain aging plays an important role in the temperature-dependent variations in deformation and fracture behavior, including the FCG parameters. Another important aspect in deciding the FCG behavior is the crack closure behavior, the mechanisms of which may vary with temperature. Effect of crack closure and DSA on the FCG properties of P91 steel and SS 316L(N) welds will be discussed. The DSA mechanism has been identified from the activation energy for the process determined from the temperature dependence of the crack tip strain rates. During FCG of engineering materials, there can be stress shielding at the crack tip because of various factors, like crack bridging, branching, closure, etc. Effect of stress shielding at the crack tip at different conditions was quantified using a procedure incorporating the inter relations between compliance, crack length, and stress intensity factor. The paper will summarize the results of the above studies.
Download or read book Fatigue of Ferritic and Austenitic Steels written by and published by . This book was released on 1991 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: One aim of this research program has been to increase our understanding of the mechanisms of fatigue crack growth as influenced by such parameters as the specific material, crack length, R-ratio, overloads, temperature and the environment. A second objective has been to utilize this understanding in the development of semi-empirical quantitative methods for the prediction of fatigue crack growth behavior. Although there are still many questions remaining concerning fatigue crack growth, we feel that some significant progress in meeting these two objectives has been made.
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 An Elevated Temperature Fatigue Crack Model for Stainless Steels written by J-Y Guinemer and published by . This book was released on 1982 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: A model has been developed for the prediction of cyclic crack growth rates at different frequencies and has been verified for an austenitic stainless steel at elevated temperature. The model is based on the damage concept, and accounts for the viscoplastic behavior of stainless steels at elevated temperature. The inclusion of a creep component in such a model results in good correlation between the predicted and observed data.
Download or read book Specimen Size considerations in Fatigue Crack Growth Rate Testing written by and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of specimen size upon the fatigue-crack growth behavior of annealed AISI Type 304 stainless steel was studied at two stress ratios at an elevated temperature. The resulting data were examined in the light of the present ASTM size criterion (based upon monotonic yield stength) as well as a proposed criterion based upon the material flow strength. The flow stress criterion is considerably less restrictive than the present ASTM Criterion, and the results of this study indicate that the flow stress criterion is entirely appropriate for strain-hardening materials such as the austenitic stainless steels.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 1572 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Specimen Size Considerations in Fatigue Crack Growth Rate Testing written by LA. James and published by . This book was released on 1981 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of specimen size upon the fatigue crack growth rate behavior of annealed AISI Type 304 stainless steel was studied at two stress ratios at an elevated temperature. The resulting data were examined in the light of the present ASTM size criterion (based upon monotonic yield strength) and a proposed criterion based upon the material flow strength. The flow stress criterion is considerably less restrictive than the present ASTM criterion. The results of this study indicate that the flow stress criterion is entirely appropriate for strain-hardening materials such as austenitic stainless steels.
Download or read book Fatigue of Ferritic and Austenitic Steels Final Technical Report June 1 1984 July 31 1991 written by and published by . This book was released on 1991 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: One aim of this research program has been to increase our understanding of the mechanisms of fatigue crack growth as influenced by such parameters as the specific material, crack length, R-ratio, overloads, temperature and the environment. A second objective has been to utilize this understanding in the development of semi-empirical quantitative methods for the prediction of fatigue crack growth behavior. Although there are still many questions remaining concerning fatigue crack growth, we feel that some significant progress in meeting these two objectives has been made.
Download or read book Fatigue Crack Propagation in Austenitic Stainless Steels at Cryogenic Temperatures written by Zequn Mei and published by . This book was released on 1990 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermal fatigue Crack growth Characteristics and Mechanical Strain Cycling Behavior of A 286 Discaloy and 16 25 6 Austenitic Steels written by Robert W. Smith and published by . This book was released on 1960 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Metal Fatigue Effects of Small Defects and Nonmetallic Inclusions written by Yukitaka Murakami and published by Elsevier. This book was released on 2002-04-29 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metal fatigue is an essential consideration for engineers and researchers who are looking at factors that cause metals to fail through stress, corrosion, etc. This is an English translation of a book originally published in Japan in 1993, with an additional two chapters on the fatigue failure of steels and the effect of surface roughness on fatigue strength. The methodology is based on important and reliable results and may be usefully applied to other fatigue problems not directly treated in this book.
Download or read book A Critical Analysis of Grain Size and Yield Strength Dependence of Near Threshold Fatigue Crack Growth in Steels written by GR. Yoder and published by . This book was released on 1983 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: Near-threshold fatigue crack growth behavior has been analyzed for a broad selection of steels surveyed from the literature. It is clear first of all that apparent values of the threshold stress-intensity factor (?Kth) can vary widely, roughly an order of magnitude. Though in many instances actual ?Kth values are difficult to define rigorously, a pronounced transition point or "knee" is apparent in the near-threshold region of the conventional logarithmic plot of fatigue crack growth rate (da/dN) as a function of stress-intensity range (?K). Though the values of ?K associated with these transition points (?KT) for an individual steel may tend to exhibit a functional dependence on yield strength (?ys) or grain size ( ̄l)--as is the case, for example, with a low-carbon ferritic steel--it is unmistakably clear that for the gamut of steels examined (15 cases), the transition points do not order on the basis of either ?ys or ̄l alone. Rather, values of ?KT for the gamut of steels order on the basis of a synergetic interaction of ?ys and ̄l, according to the equation, ?KT=5.5?ysl ̄. This relationship was derived in the cyclic plastic zone model of fatigue crack growth established in our prior work with titanium alloys. In further agreement with this model, ?KT has been identified for these steels as the point at which the cyclic plastic zone attains the mean grain size. The significance and implications of these findings appear far-reaching, as the steels surveyed include those of both high and low strength, a wide range of effective grain sizes (mean free path in the case of high-strength steel), and a host of microstructural types (ferritic, martensitic, pearlitic, bainitic, and austenitic).
Download or read book NEAR THRESHOLD FATIGUE CRACK PROPAGATION IN FERRITIC STAINLESS STEELS AT ELEVATED TEMPERATURES written by KAMEL MAKHLOUF and published by . This book was released on 1991 with total page 169 pages. Available in PDF, EPUB and Kindle. Book excerpt: and without excessive plasticity.
Download or read book Fatigue Crack Growth Behavior in a Nitrogen Strengthened High Manganese Steel at Cryogenic Temperatures written by JW. Morris and published by . This book was released on 1985 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fatigue crack growth rate (FCGR) of a nitrogen-strengthened high-manganese stainless steel of nominal composition 18Mn-5Ni-16Cr-0.02C-0.22N was determined in the intermediate stress-intensity factor range (20-70 MPa?m) at 77 and 4 K. Fractographic investigations were performed on the fracture surfaces. The FCGR at 4 K was very nearly the same as at 77 K and substantially below the FCGR for AISI 304LN steel. The fracture surfaces of both the high-manganese alloy and the 304LN showed a transgranular failure mode, but the detailed fractographic features varied with temperature and alloy type. The fractography was closely related to changes in the FCGR.
Download or read book Effect of Environment on Crack Growth Behavior in Austenitic Stainless Steels Under Creep and Fatigue Conditions written by K. Sadananda and published by . This book was released on 1979 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Environment Chemistry and Microstructure on the Corrosion Fatigue Behavior of Austenitic Stainless Steels in High Temperature Water written by Lindsay Beth O'Brien and published by . This book was released on 2014 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effect of sulfur on the corrosion fatigue crack growth of austenitic stainless steel was evaluated under Light Water Reactor (LWR) conditions of 288°C deaerated (less than 5ppb O2) water, to shed light on the accelerating effect of the LWR environment and to explore the effect of high sulfur content on the retardation of fatigue crack growth rates. Fatigue tests were performed using a trapezoidal loading pattern with rise times of 5.1, 51, 510, and 5100 seconds (fall time of 0.9, 9, 90, and 900 seconds), with Kmzx of 28.6 or 31.9 MPa[mathematical symbol]m and stress ratios (R, Pmin/Pmax) of 0.4 or 0.7. Two test materials were used to evaluate the effect of sulfur: (1) a low sulfur (
Download or read book Energy Research Abstracts written by and published by . This book was released on 1988 with total page 752 pages. Available in PDF, EPUB and Kindle. Book excerpt:
