Download or read book Effect of Notches on Creep fatigue Behavior of a P M Nickel based Superalloy written by Jack Telesman and published by . This book was released on 2015 with total page 24 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:
Download or read book Life Prediction Techniques for Analyzing Creep Fatigue Interaction in Advanced Nickel Base Superalloys written by M. N. Menon and published by . This book was released on 1976 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: ON THE BASIS OF THE LIMITED DATA THAT ARE PRESENTED IN THIS STUDY, IT MAY BE CONCLUDED THAT THE EFFECT OF CREEP DAMAGE ON THE LOW CYCLE FATIGUE BEHAVIOR OF Rene 95 at 1200 F is not very severe. This is probably because of the good stress rupture properties of the material at this temperature. Strain Range Partitioning approach does not seem to hold much promise for analyzing, and therefore, for predicting strain controlled low cycle fatigue behavior of Rene 95 under creep-fatigue conditions at 1200 F. When compared to the SRP approach, the Frequency Modified approach appears less cumbersome and, hence, more advantageous. The present study indicates, however, that the FM approach using the frequencies calculated on the basis of the actual cycles holds only a slight edge over that involving unmodified inelastic strain range versus cyclic life representation. At present, the damage approach proposed by Ostergren seems to offer more potential as it takes into account the aspect of loop shift that accompanies fatigue cycling of Rene 95.
Download or read book Microstructural Effects and Fatigue Life Predictions of Notched and Un notched Nickel Base Superalloys at Elevated Temperatures written by Stephen D. Antolovich and published by . This book was released on 1978 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: The low cycle fatigue (LCF) of Rene 80 has been investigated at 1400, 1600 and 1800 F. Emphasis has been placed on the 1800 F studies using smooth bar (continuous cycling and 90 sec hold time) and notch LCF specimens. The detailed transmission electron microscopy shows that at 1600 and 1800 F the dislocation debris is independent of test rate over two orders of magnitude. The test results can not be explained in terms of the conventional approaches to high temperature LCF for which damage is assumed to result from creep/fatigue interactions. Instead, it is suggested that the important damage mechanism is an interaction between the deformation mode and the environment. Based on that understanding a model is developed for crack propagation at elevated temperatures and a similar model is being developed for crack initiation. (Author).
Download or read book Microstructural Effects and Fatigue Life Predictions of Notched and Un notched Ni Base Superalloys at Elevated Temperatures written by Stephen D. Antolovich and published by . This book was released on 1980 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: The LCF(Low Cycle Fatigue) behavior of Ni base superalloys was studied both for smooth and notched test bars. The primary research material was Rene 80 which finds application in turbine blades used in the temperature range of 650-982 C (1200-1800 F). The smooth bar LCF behavior was studied in the as-heat treated condition and also after exposure for 100h at 982 C, either under a stress of 97 MPa (14 ksi) or OMPa. Test conditions included continuous cycling at different strain rates as well as 90 second hold periods at either maximum or minimum strain. The primary test temperatures were 871 C (1600 F) and 982 C (1800 F). It was found that prior exposure greatly reduces the fatigue life. Since these experiments tend to duplicate actual engine conditions, use of data obtained using as-heat treated specimens may be very non-conservative to predict lives of actual components. The test results correlated very well with a model for LCF which is based on the concept that cracks initiate at a critical combination of oxide depth and stress. The notch LCF problem was also studied. A computer model for calculating local stresses and strains was developed. In addition to the Rene 80 studies, some initial smooth bar LCF studies were carried out using Rene 77.
Download or read book Elevated Temperature Fatigue Creep Behavior of Nickel Base Superalloy IN 625 written by A. Biron and published by . This book was released on 1988 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: A research program has been carried out to establish the low-cycle fatigue and creep-fatigue behaviors of Inconel 625 at elevated temperatures (650 and 815°C). The main observations were related to the effect of temperature and of hold times. Under continuous cycling, a temperature increase from 650 to 815°C caused a reduction in the fatigue life by a factor of 2 at a high strain and by a factor of 3 at a low strain.
Download or read book Effects of Notches on Elevated temperature Low cycle Fatigue Behavior of Type 204 Stainless Steel 593 sup 0 C written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The results of an investigation into the effects of geometric stress concentrations on the elevated-temperature low-cycle fatigue behavior of Type 304 stainless steel are presented. The objective of this study was to develop a data base that could be used to verify the ASME Code Case 1592-8 design method for predicting the creep-fatigue behavior of structural components which contain discontinuities. In continuous-cycling tests, the local strains at the notch root determined from the Code Case procedure result in fatigue-life estimates that are conservative when compared to the experimental values. For tests containing a hold time at the peak tensile strain, the Code Case procedure results in local strains that are nearly identical to the experimentally obtained local strains, if the local stress is assumed to relax to the nominal value during the hold time.
Download or read book Creep Fatigue Behavior of Ni Co Cr Al Y Coated PWA 1480 Superalloy Single Crystals written by J. Gayda and published by . This book was released on 1988 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: Single-crystal specimens of a Ni-base superalloy, PWA 1480, with a low pressure plasma sprayed Ni-Co-Cr-Al-Y coating, were tested in various 0.1 Hz fatigue and creep-fatigue cycles at 1015 and 1050°C. Creep-fatigue tests of the cp, pc, and cc types were conducted with various constant total strain ranges employing creep dwells at various constant stresses. Considerable cyclic softening occurred as was evidenced particularly by rapidly increasing creep rates in the creep-fatigue tests. The cycle time in the creep-fatigue tests typically decreased by more than 80% at 0.5 Nf.
Download or read book EFFECTS OF NOTCHES ON LOW CYCLE FATIGUE A Literature Survey written by B. M. Wundt and published by ASTM International. This book was released on with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 The Effect of Elevated Temperature Pre exposure on the Creep fatigue Crack Growth Behaviour of a Polycrystalline Nickel base Superalloy written by D. W. Hunt and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fatigue Behavior of a Nickel Based Directionally Solidified Superalloy at Elevated Temperature written by Louis Domenic Terranova and published by . This book was released on 1989 with total page 232 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Deformation and Fatigue Behavior of the Nickel base Superalloy KM4 written by Amit Shyam and published by . This book was released on 2002 with total page 668 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sensitivity of the Creep Rupture Properties of Nickel Base Superalloy Sheet to Sharp Edge Notches in the Temperature Range of 1000 Deg 1400 Deg F written by and published by . This book was released on 1969 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Investigations are now in progress to evaluate the severe time- dependent, edge-notch sensitivity known to occur in thin sheet nickel-base superalloys exposed under stress at 1000 and 1200F. Studies of Rend 41, Waspaloy and Inconel 718, over a wide range of heat-treated conditions, has served to define the scope of this problem in 0. 026-inch thick sheet. In addition, exploratory data have been obtained on the influence of notch acuity and sheet thickness on the notch sensitivity. Both smooth and edge-notched specimens fractured by the initiation and growth of intergranular cracks, followed by abrupt transgranular fracture due to the increase in stress caused by creep cracking. Analysis of these processes showed that the degree of notch sensitivity was strongly dependent upon the effect of the notches on the time required for the initiation of the creep crack and the early stages of its growth. There were some differences among alloys and within an alloy with heat treatment and test temperature. The notch sensitivity was not exhibited for the testing time periods considered when sheet thickness was increased from 0.026- to 0.050-inch. This, together with other considerations, suggests that the stress and strain state is a major factor. Until this is understood, however, it is not possible to correlate notch sensitive behavior with precise microstructural features or mechanical properties.
Download or read book Effects of Notches on Elevated temperature Low cycle Fatigue Behavior of Type 204 Stainless Steel 593 C written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The results of an investigation into the effects of geometric stress concentrations on the elevated-temperature low-cycle fatigue behavior of Type 304 stainless steel are presented. The objective of this study was to develop a data base that could be used to verify the ASME Code Case 1592-8 design method for predicting the creep-fatigue behavior of structural components which contain discontinuities. In continuous-cycling tests, the local strains at the notch root determined from the Code Case procedure result in fatigue-life estimates that are conservative when compared to the experimental values. For tests containing a hold time at the peak tensile strain, the Code Case procedure results in local strains that are nearly identical to the experimentally obtained local strains, if the local stress is assumed to relax to the nominal value during the hold time.
Download or read book A Study of Creep fatigue Interaction in a New Nickel based Superalloy written by Zhilan Zhan and published by . This book was released on 2004 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Creep Fatigue Environment Interactions in Superalloys written by and published by . This book was released on 1981 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: The fatigue-creep-environment interactions in nickel base superalloys were investigated from 650 C to 760 C in the low cycle fatigue range and in the crack growth mode as a function alloy chemistry and microstructure. Three alloys, conventionally cast and forged Waspaloy, powder metallurgy as-hot isostatically pressed low carbon Astroloy, and powder metallurgy superplastically forged IN-100 were compared by room and elevated temperature low cycle fatigue testing under control of total strain range. It was found that at 427 C and 649 C Waspaloy had the longest fatigue lifetimes followed by low carbon Astroloy, then IN-100, but IN-100 had the highest cyclic flow stress and Waspaloy the lowest. On the basis of its relatively good combination of fatigue properties, homogenity and isotropy resulting from powder processing, and because it can be heat treated to a wide variety of different microstructures, one alloy, low carbon Astroloy was selected for a program to systematically determine the effects of changes in microstructure on elevated temperature fatigue behavior. Low carbon Astroloy was heat treated to four very different microstructures with various combinations of fine (500A) and coarse (2000-8000A) matrix gamma and grain boundaries with and without carbides and primary gamma'.
