Download or read book Fatigue at High Temperature written by American Society for Testing and Materials and published by ASTM International. This book was released on 1969 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High temperature Low cycle Fatigue Experiments on Hastelloy X written by A. E. CARDEN and published by . This book was released on 1969 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High temperature Low cycle Fatigue Experiments on Hastelloy X written by and published by . This book was released on 1969 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fatigue at High Temperature written by and published by ASTM International. This book was released on 1969 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High temperature Low cycle fatigue and Crack growth Behaviors of Three Superalloys written by and published by . This book was released on 2005 with total page 329 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extensive smooth-bar low-cycle-fatigue (LCF) and fatigue crack growth (FCG) experiments on three solid-solution-strengthened superalloys HASTELLOY X, HAYNES 230, and HAYNES 188 have been conducted at 816 and 927°C. Limited tests were run at 649°C, 871°C, and 982°C to study the temperature effect. The LCF tests were performed under a total-strain-range-control mode at Solar Turbines Inc., Metcut Research Inc., and The University of Tennessee (UT). The FCG tests were done under both the constant-load-range and constant-stress-intensity-factor-range modes at Westmoreland Testing Inc. and UT. Various hold times were imposed at the maximum strain or load in both the LCF and FCG tests, respectively, to investigate the hold-time effect. For the LCF tests, the influence of the total strain range and hold time on the cyclic stress response was determined at temperatures ranging from 816 to 982°C. At the temperatures considered, the HASTELLOY X alloy exhibited initial cyclic hardening, followed by a saturated cyclic-stress response or cyclic softening under LCF without hold times. For LCF tests with hold times, however, the alloy showed cyclic hardening, cyclic stability, or cyclic softening, which is closely related to the test temperature and the duration of the hold time. It was also observed that the LCF life of the X alloy considerably decreased due to the introduction of strain hold times. Generally, a longer hold time would result in a greater reduction in the fatigue life. For the tests without hold times, the test temperature seems to have little influence on the fatigue life of the X alloy at the test temperatures from 816 to 927°C. However, when the test temperature increased to 982°C, the fatigue life clearly shortened. The effects of heat-to-heat variation on the cyclic stress response were illustrated. A parameter based on the hysteresis energy was proposed to rationalize the LCF life data with and without hold times. In general, the fatigue life of HAYNES 230 alloy decreased as the temperature increased. However, at total strain ranges higher than 1.0% and without a hold time, the LCF life was longer at 927°C than at 816°C. This "abnormal" behavior was found to result from the smaller plastic strain amplitude at half-life at 927°C than that at 816°C. The introduction of a hold time led to a decrease in the fatigue life. At both 816 and 927°C, the material exhibited a cyclic hardening/softening behavior at higher total strain ranges and a cyclic hardening/saturation behavior at lower total strain ranges. An increase in the temperature and/or the introduction of a hold time decreased the hardening rate and increased the softening rate. The introduction of a hold time and/or the increase of the test temperature progressively changed the fracture mode from the transgranular to mixed trans/inter-granular, then to intergranular feature. Within the two phases of the fatigue process, crack initiation was more severely influenced by the change of the hold time and/or temperature. For the LCF of HAYNES 188 alloy, in the total-strain ranges used in this investigation, increasing the test temperature from 816 to 982°C shortened the fatigue life. This effect is especially clear at total-strain ranges smaller that 1.0%. Introducing hold times at the maximum tensile strain is found to lead to a significant reduction in the fatigue life. The HAYNES 188 alloy can exhibit cyclic hardening, cyclic hardening followed by softening or the saturated stress response, and cyclic softening during LCF deformation, which is closely related to the test temperature, the imposed total strain range, and the hold time. In addition, the HAYNES 188 alloy shows the heat-to-heat variation in the cyclic stress response curve. The FCG data were analyzed with an emphasis on hold-time and temperature effects. For both alloys, the crack grew faster at a higher temperature. It was also noted that the introduction of a hold time at the maximum load led to an increase in the cyclic crack-growth rate. The longer hold time gave the faster crack-growth rate, which was related to the gradual transition from transgranular to intergranular cracking. The crack-growth rates in the fatigue and creep tests were correlated with the stress-intensity-factor range, [delta]K, and the stress-intensity factor, K, respectively. The crack-propagation rates in the hold-time tests were predicted from the crackgrowth rates obtained from both the fatigue and the creep crack-growth tests, using a semi-empirical linear summation model. Crack-growth-rate predictions reproduce most of the characteristics observed experimentally. The crack-growth-rate data obtained from the FCG testing under load-range and stress-intensity-factor-rangecontrol modes were compared. In addition, time-dependent fracture-mechanics parameters, C*, C[subscript t], and (C[subscript t])[subscript avg], were applied to correlate the crack-growth rates. For both alloys, the fatigue-cracking path was mainly transgranular at 816 and 927°C. The cracking path became dominantly intergranular if the hold time increased to 2 min., indicating that the time-dependent damage mechanisms, creep and/or oxidation, were in control. When the time-dependent damage dominated (temperature [greater or lesser than] 816°C and hold time [greater or lesser than] 2 min.), the crack-growth rates can be correlated with C[subscript t] or (C[subscript])[subscript avg] parameters. The C[subscript t] and (C[subscript t])[subscript avg] parameters were capable of consolidating data from different temperatures and alloys. The fracture surfaces of both LCF- and FCG-tested samples were examined with the scanning-electron-microscopy (SEM). The tests in this study were conducted at high temperatures in air. Therefore, the fracture surfaces were frequently covered with a dark layer of oxides, making the fracture features difficult to identify. To overcome this problem, for the LCF testing, the failed samples were cut longitudinally through the fracture surfaces, and the sections were observed to locate secondary cracks. By combining the fractographic and metallographic results, the crack initiation and propagation for all tests were successfully investigated. However, for the FCG-failed samples, the major secondary cracks on specimen surfaces were not available. An oxide-stripping technique has been developed to overcome the oxide-layer problem. The technique consists of two steps. The sample is first boiled in a potassium permanganate solution for 1 hr, and then electrolytically cleaned in an alkaline solution for 5 min. with the sample as the cathode. Except for dislodging the carbides, the technique developed was capable of removing the oxides completely without altering the fracture-surface morphology.

Download or read book Thermomechanical Fatigue Behavior of Materials written by Huseyin Sehitoglu and published by ASTM International. This book was released on 1993 with total page 259 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book hold time effects in high temperature low cycle fatigue written by and published by ASTM International. This book was released on 1971 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Improved Techniques for Thermomechanical Testing in Support of Deformation Modeling written by Michael G. Castelli and published by . This book was released on 1992 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Multiaxial Fatigue and Deformation written by Sreeramesh Kalluri and published by ASTM International. This book was released on 2000 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contains papers from a May 1999 symposium, describing state-of-the-art multiaxial testing techniques and analytical methods for characterizing fatigue and deformation behaviors of engineering materials. Papers are classified into sections on multiaxial strength of materials, multiaxial deformation,

Download or read book Energy Research Abstracts written by and published by . This book was released on 1990 with total page 834 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Reactor Technology written by and published by . This book was released on 1972 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1988 with total page 972 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fatigue Damage written by Filippo Berto and published by MDPI. This book was released on 2018-07-02 with total page 211 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a printed edition of the Special Issue "Fatigue Damage" that was published in Metals

Download or read book High temperature Low cycle Fatigue and Tensile Properties of Hastelloy X and Alloy 617 in Air and HTGR helium written by and published by . This book was released on 1981 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Results of strain controlled fatigue and tensile tests are presented for two nickel base solution hardened alloys which are reference structural alloys for use in several high temperature gas cooled reactor concepts. These alloys, Hastelloy X Inconel 617, were tested at temperatures ranging from room temperature to 871°C in air and impure helium. Materials were tested in the solution annealed as well as in the pre-aged condition where aging consisted of isothermal exposure at one of several temperatures for periods of up to 20,000 h. Comparisons are also given between the strain controlled fatigue lives of these alloys and several other commonly used alloys all tested at 538°C.

Download or read book Engine Structures written by and published by . This book was released on 1988 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Low cycle Fatigue Evaluation for Regeneratively Cooled Panels written by and published by . This book was released on 1971 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NASA Technical Memorandum written by and published by . This book was released on 1988 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: