Download or read book The Effect of Weld Heat affected Zone Hot Cracks on the Fatigue Crack Growth Behavior of As cast Alloy 718 written by Edwin L. Bradley and published by . This book was released on 1988 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Superalloy 718 written by E. A. Loria and published by . This book was released on 1989 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Heat Treatment Upon the Fatigue crack Growth Behavior of Alloy 718 Weldments Part II Microscopic Behavior written by and published by . This book was released on 1981 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt: The microstructural features that influenced the room and elevated temperature fatigue-crack growth behavior of as-welded, conventional heat-treated, and modified heat-treated Alloy 718 GTA weldments were studied. Electron fractographic examination of fatigue fracture surfaces revealed that operative fatigue mechanisms were dependent on microstructure, temperature and stress intensity factor. All specimens exhibited three basic fracture surface appearances at temperatures up to 838°C: crystallographic faceting at low stress intensity range (?K) levels, striation formation at intermediate values, and dimples coupled with striations in the highest?K regime. At 649°C, the heat-treated welds exhibited extensive intergranular cracking. Laves and?particles in the conventional heat-treated material nucleated microvoids ahead of the advancing crack front and caused an overall acceleration in crack growth rates at intermediate and high?K levels. The modified heat treatment removed many of these particles from the weld zone, thereby improving its fatigue resistance. The dramatically improved fatigue properties exhibited by the as-welded material was attributed to compressive residual stresses introduced by the welding process. 16 figures.
Download or read book Effect of Heat Treatment Upon the Fatigue crack Growth Behavior of Alloy 718 Weldments written by and published by . This book was released on 1981 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The microstructural features that influenced the room and elevated temperature fatigue-crack growth behavior of as-welded, conventional heat-treated, and modified heat-treated Alloy 718 GTA weldments were studied. Electron fractographic examination of fatigue fracture surfaces revealed that operative fatigue mechanisms were dependent on microstructure, temperatures and stress intensity factor. All specimens exhibited three basic fracture surface appearances at temperatures up to 538°C: crystallographic faceting at low stress intensity range ([Delta]K) levels, striation, formation at intermediate values, and dimples coupled with striations in the highest ([Delta]K) regime. At 649°C, the heat-treated welds exhibited extensive intergranular cracking. Laves and [delta] particles in the conventional heat-treated material nucleated microvoids ahead of the advancing crack front and caused on overall acceleration in crack growth rates at intermediate and high [Delta]K levels. The modified heat treatment removed many of these particles from the weld zone, thereby improving its fatigue resistance. The dramatically improved fatigue properties exhibited by the as-welded material was attributed to compressive residual stresses introduced by the welding process. 19 refs., 16 figs.
Download or read book Metals Abstracts written by and published by . This book was released on 1994 with total page 1584 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Heat Treatment upon the Fatigue Crack Growth Behavior of Alloy 718 Weldments Part 1 Macroscopic Behavior written by James LA. and published by . This book was released on 1981 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Product Form Upon Fatigue crack Growth Behavior in Alloy 718 written by and published by . This book was released on 1980 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A previous study had characterized the fatigue-crack growth behavior of four wrought product forms (sheet, plate, bar and forging) from a single heat of Alloy 718 and concluded that there were no consistent trends in the crack growth rate results that could be attributed to product form variability. The present study adds one additional product form (gas-tungsten-arc weldments) from the same heat, and compares the behavior to that exhibited by the wrought product forms. Two different precipitation heat-treatments were employed at each of five test temperatures. 11 refs., 5 figs., 3 tabs.
Download or read book Effect of Product Form Upon Fatigue crack Growth Behavior in Alloy 718 written by and published by . This book was released on 1980 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: A previous study had characterized the fatigue-crack growth behavior of four wrought product forms (sheet, plate, bar and forging) from a single heat of Alloy 718 and concluded that there were no consistent trends in the crack growth rate results that could be attributed to product form variability. The present study adds one additional product form (gas-tungsten-arc weldments) from the same heat, and compares the behavior to that exhibited by the wrought product forms. Two different precipitation heat-treatments were employed at each of five test temperatures (24, 316, 427, 538, and 649°C).
Download or read book Effect of Heat Treatment upon the Fatigue Crack Growth Behavior of Alloy 718 Weldments Part 2 Microscopic Behavior written by James LA. and published by . This book was released on 1981 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemical Abstracts written by and published by . This book was released on 2002 with total page 2726 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Data sheet on fatigue crack growth properties of cast alloy 718 written by and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Heat Treatment on Fatigue Crack Propagation and Deformation Mode in Alloy 718 at Elevated Temperatures written by H. H. Smith and published by . This book was released on 1978 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: Alloy 718 is a commercial, wrought nickel-base alloy widely utilized in moderate temperature structural applications and has been proposed for use in advanced nuclear systems. In such applications, Alloy 718 will experience the combined effects of cyclic and static loading and sustained elevated temperatures. However, when used in structures requiring welds, Alloy 718 exhibits reduced weld ductility and strain age cracking when given conventional post-weld duplex age heat treatments. A modified heat treatment has been previously proposed to obviate these problems and thereby improve structural reliability. The effect of conventional and modified heat treatments and combined cyclic and static loading (hold time) on crack propagation and deformation mode in two heats of Alloy 718 plate material was investigated at 427 and 593 deg C. The fatigue results show that, in general, the resistance of Alloy 718 to crack propagation at these temperatures was not adversely affected by the modified heat treatment and, under most conditions, was found to be improved in comparison with the conventional heat treatment. Scanning electron microscopy (SEM) examination of the fracture surfaces of the fatigue specimens revealed that the failure mode was dependent on test temperature and heat treatment. The material given the conventional heat treatment exhibited transgranular failure modes at both test temperatures. On the other hand, the modified heat treatment produced transgranular fractures at 427 deg C and intergranular or a mixed failure mode at 593 deg C.
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1998 with total page 984 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Alloys Index written by and published by . This book was released on 1992 with total page 882 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Size Effect on the Fatigue Crack Growth Rate Threshold of Alloy 718 written by GC. Hresko and published by . This book was released on 2000 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fatigue crack growth rate (FCGR) tests were conducted on Nickel-based uperalloy 718 in the solution annealed and aged condition at room temperature. In each test, the FCGR threshold was measured using the K-decreasing constant R method. Initial testing was at two facilities, one of which used C(T) specimens with W = 127 mm. Previous data at the other facility had been obtained with specimens with W = 50.8 mm. A comparison of test results at R = 0.1 showed that the threshold for the 127 mm specimen was considerably higher than that of the 50.8 mm specimen. A check showed that this difference was not due to a heat-to-heat or lab-to-lab variation. Additional tests were conducted on specimens with W = 25.4 mm and at other R values. Data for the various specimens is presented along with parameters usually used to describe threshold behavior.
Download or read book Fatigue crack Propagation Behavior of Inconel 718 written by and published by . This book was released on 1975 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The techniques of linear-elastic fracture mechanics were used to characterize the effect of several variables (temperature, environment, cyclic frequency, stress ratio, and heat-treatment variations) upon the fatigue-crack growth behavior of Inconel 718 base metal and weldments. Relevant crack growth data on this alloy from other laboratories is also presented. (33 fig, 39 references) (auth).
Download or read book Hot Cracking Phenomena in Welds II written by Thomas Böllinghaus and published by Springer Science & Business Media. This book was released on 2008-08-07 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt: Failure of welded components can occur during service as well as during fabrication. Most common, analyses of the resistance of welded components against failure are targeted at crack avoidance. Such evaluations are increasingly carried out by modern weldability studies, i. e. considering interactions between the selected base and filler materials, structural design and welding process. Such weldability investigations are particularly targeted to prevent hot cracking, as one of the most common cracking phenomena occurring during weld fabrication. To provide an international information and discussion platform to combat hot cracking, an international workshop on Hot Cracking Phenomena in Welds has been created, based on an initiative of the Institute for Materials and Joining Technology at the Otto-von-Guericke University in Magdeburg and the Division V. 5 – Safety of Joined Components at the Federal Institute for Materials Research and Testing (BAM) in Berlin, Germany. The first workshop was organized in Berlin under the topics mechanisms and phenomena, metallurgy and materials, modelling and simulations as well as testing and standardization. It consisted of 20 individual contributions from eight countries, which were compiled in a book that found a very ready market, not only in the welding community. As a consequence of increasing interest, it has been decided to establish the Workshop on Hot Cracking Phenomena in Welds as a regular event every three years embedded in the International Institute of Welding (IIW). Attached to the IIW Commission IX and II Spring intermediate meetings, the second workshop was organized in March 2007.
