[PDF] Speciman Size Effects In Charpy Impact Testing eBook

Author : DJ. Alexander
Publisher :
Page : 13 pages
File Size : 46,65 MB
Release : 1990
Category : Charpy
ISBN :

GET BOOK

Full-size, half-size, and third-size specimens from several different steels have been tested as part of an ongoing alloy development program. The smaller specimens permit more specimens to be made from small trial heats and are much more efficient for irradiation experiments. The results of several comparisons between the different specimen sizes have shown that the smaller specimens show qualitatively similar behavior to large specimens, although the upper-shelf energy level and ductile-to-brittle transition temperature are reduced. The upper-shelf energy levels from different specimen sizes can be compared by using a simple volume normalization method. The effect of specimen size and geometry on the ductile-to-brittle transition temperature is more difficult to predict, although the available data suggest a simple shift in the transition temperature due to specimen size changes. The relatively shallower notch used in smaller specimens alters the deformation pattern, and permits yielding to spread back to the notched surface as well as through to the back. This reduces the constraint and the peak stresses, and thus the initiation of cleavage is more difficult. A better understanding of the stress and strain distributions is needed.

Author : Lonnie Eugene Schubert
Publisher :
Page : 0 pages
File Size : 35,60 MB
Release : 1995
Category :
ISBN :

GET BOOK

"This study was undertaken to correlate the impact properties of ASTM standard full size Charpy V-notch impact specimens to the impact properties of subsize specimens. An ASTM A533-B quenched and tempered plate steel was examined. The fine grained martensitic material had a coarse prior austenite grain size, which resulted in a low upper shelf energy for this material. Three sizes of specimens were included. Specimens were irradiated in the TRIGA Reactor Facility operated by the U.S. Geological Survey in Denver, Colorado, to 1 x 1019 n/cm2 (E> 1 MeV) at 150°C (302°F). Unirradiated and irradiated specimens were tested at several temperatures in an instrumented drop tower, and the load during impact was recorded as a function of time. Full transition curves of energy versus temperature were determined for the three sizes. The results are presented and compared. A method for correlating the upper shelf energies determined from subsize and full size specimens was developed. The method incorporated a normalizing factor proposed in earlier related studies, and the method is discussed in light of the new data. The estimates of upper shelf energy derived from the correlation agreed with the measured full size values within 10%. The correlation was found to be applicable to the subsize specimen data. The irradiation induced shift in the ductile to brittle transition temperature of the material was found to be independent of specimen size"--Abstract, leaf iii

Author : W. R. Corwin
Publisher : ASTM International
Page : 630 pages
File Size : 50,2 MB
Release : 1998
Category : Light water reactors
ISBN : 0803124767

GET BOOK

As part of an increasing interest in radiation embrittlement for aging nuclear reactors, scientists gathered in New Orleans in January 1997 to consider the interests and capabilities of the scientific-testing community and of the commercial light-water-cooled power-reactor industry in terms of improving methods to characterize component integrity. The resulting 37 papers concentrate on the use of unique small and miniature specimens; nondestructive, nonintrusive, and in- situ test techniques for measuring mechanical and fracture properties; the application of tests to irradiation-induced embrittlement; and actual examples of tests to determine material integrity and to evaluate potential component life extension. They consider experimental, analytical, and computational aspects. Annotation copyrighted by Book News, Inc., Portland, OR

Author : D. Francois
Publisher : Elsevier
Page : 497 pages
File Size : 26,86 MB
Release : 2002-06-18
Category : Technology & Engineering
ISBN : 008052897X

GET BOOK

From Charpy to Present Impact Testing contains 52 peer-reviewed papers selected from those presented at the Charpy Centenary Conference held in Poitiers, France, 2-5 October 2001. The name of Charpy remains associated with impact testing on notched specimens. At a time when many steam engines exploded, engineers were preoccupied with studying the resistance of steels to impact loading. The Charpy test has provided invaluable indications on the impact properties of materials. It revealed the brittle ductile transition of ferritic steels. The Charpy test is able to provide more quantitative results by instrumenting the striker, which allows the evolution of the applied load during the impact to be determined. The Charpy test is of great importance to evaluate the embrittlement of steels by irradiation in nuclear reactors. Progress in computer programming has allowed for a computer model of the test to be developed; a difficult task in view of its dynamic, three dimensional, adiabatic nature. Together with precise observations of the processes of fracture, this opens the possibility of transferring quantitatively the results of Charpy tests to real components. This test has also been extended to materials other than steels, and is also frequently used to test polymeric materials. Thus the Charpy test is a tool of great importance and is still at the root of a number of investigations; this is the reason why it was felt that the centenary of the Charpy test had to be celebrated. The Société Française de Métallurgie et de Matériaux decided to organise an international conference which was put under the auspices of the European Society for the Integrity of Structures (ESIS). This Charpy Centenary Conference (CCC 2001) was held in Poitiers, at Futuroscope in October 2001. More than 150 participants from 17 countries took part in the discussions and about one hundred presentations were given. An exhibition of equipment showed, not only present day testing machines, but also one of the first Charpy pendulums, brought all the way from Imperial College in London. From Charpy to Present Impact Testing puts together a number of significant contributions. They are classified into 6 headings: •Keynote lectures, •Micromechanisms, •Polymers, •Testing procedures, •Applications, •Modelling.

Author : WR. Corwin
Publisher :
Page : 14 pages
File Size : 24,48 MB
Release : 1986
Category : Charpy specimens
ISBN :

GET BOOK

The degradation of fracture resistance of ferritic steels subjected to neutron irradiation can be qualitatively evaluated by examining the shift in the ductile-to-brittle transition temperature and the drop in the upper-shelf energy as determined in the Charpy impact test. That is an empirical test, however, and its usefulness is derived primarily from either correlation to more quantitative measures of fracture toughness or comparison with other Charpy test results for different materials or conditions of interest. Any departures from the standard testing procedures, including specimen dimensions, will yield results which will vary in some degree from those of a standard test.