[PDF] Miniaturized Charpy Specimens For The Indirect Verification Of Small Scale Charpy Machines eBook

Author : Enrico Lucon
Publisher :
Page : 11 pages
File Size : 40,63 MB
Release : 2013
Category : Horticulture
ISBN :

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Small specimen test techniques are becoming ever more popular as the need increases to characterize mechanical properties by the use of the smallest possible amount of material, because of various restrictions on material availability, irradiation, testing space, and other factors. The National Institute of Standards and Technology (NIST) is currently developing certified miniaturized Charpy V-notch (MCVN) specimens for the indirect verification of small-scale impact testing machines. The same materials used for NIST standard verification specimens are being evaluated at three energy levels (low, high, and super-high). Two specimen types are being investigated, denominated KLST (from the German Kleinstprobe, or "small specimen") and RHS (reduced half-size). Several instrumented impact tests on miniaturized KLST and RHS specimens of low, high, and super-high energy have been performed and analyzed. The variability of MCVN data has been compared to that of full-size Charpy data from the same lots of test specimens. Although this can be considered as just the preliminary phase of this project, the results indicate that MCVN verification specimens can be used for the indirect verification of small-scale instrumented impact testers, both in terms of absorbed energy and maximum force.

Author : Enrico Lucon
Publisher :
Page : 41 pages
File Size : 44,31 MB
Release : 2012
Category : Impact testing
ISBN :

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Small specimen test techniques become ever more popular as the need increases to characterize mechanical properties by use of the smallest possible amount of material, due to various restrictions on material availability, irradiation, testing space, and other factors. NIST is currently developing reference miniaturized Charpy V-notch (MCVN) specimens for the indirect verification of small-scale impact testing machines. The same materials used for NIST standard verification specimens are being evaluated at three energy levels (low, high and super-high). Two specimen types are being investigated, denominated KLST (from the German Kleinstprobe, or "small specimen") and RHS (reduced half-size). Several instrumented impact tests on miniaturized KLST and RHS specimens of low, high and super-high energy have been performed and analyzed. The variability of MCVN data has been compared to that of full-size Charpy data from the same lot of test specimens. Although this can be considered just the preliminary phase of this project, the results indicate that MCVN verification specimens can be used for the indirect verification of small-scale instrumented impact testers, both in terms of absorbed energy and maximum force. Additional aspects have also been investigated, such as the influence of shear lip symmetry and specimen fracture on absorbed energy and the correlation between miniaturized and full-size Charpy data.

Author : J. D. Splett
Publisher :
Page : 21 pages
File Size : 48,98 MB
Release : 2015
Category : Instrumented impact tests
ISBN :

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Small specimen test techniques are becoming ever more popular as the need increases to characterize mechanical properties by use of the smallest possible amount of material, because of various restrictions on material availability, irradiation, testing space, and other factors. The National Institute of Standards and Technology (NIST) recently qualified reference miniaturized Charpy V-notch (MCVN) specimens for the indirect verification of small-scale impact testing machines (with capacity in the range 15 J to 50 J and impact velocity around 3.8 m/s). The same materials used for NIST standard verification specimens were evaluated at three energy levels (low, high, and super-high). The miniaturized specimen type investigated is denominated KLST (from the German Kleinstprobe, or "small specimen"). In the first phase of the qualification activity, several instrumented impact tests on miniaturized KLST specimens of low, high, and super-high energy were performed and analyzed at NIST. In this part of the study, which was published elsewhere [Lucon, E., "Certified Miniaturized Charpy Specimens for the Indirect Verification of Small-Size Impact Machines," Mater. Perform. Character., Volume 2, No. 1, 2013], the variability of MCVN data was compared to that of full-size Charpy data from the same lot of specimens. Additional aspects were also investigated, such as the influence of shear lip symmetry and specimen full or partial fracture on absorbed energy, and the correlation between miniaturized and full-size Charpy data. In the second phase of the qualification activity, certified values of absorbed energy and maximum force were established for each energy level by means of an international round robin, which involved nine highly qualified laboratories. The results of this round robin, and the outcome of the statistical analyses performed in accordance with ASTM E691-13 (ASTM E691-13: Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method, ASTM International, West Conshohocken, PA) and ISO 5725-2 [ISO 5725-2, 1994, "Accuracy (Trueness and Precision) of Measurement Methods and Results," International Organization for Standardization, Geneva, Switzerland], are presented in this paper. Complete details are provided by NIST [Lucon, E., McCowan, C., Santoyo, R., and Splett, J., "Standard Reference Materials--Certification Report for SRM 2216, 2218, 2219: KLST (Miniaturized) Charpy V-Notch Impact Specimens," NIST Special Publication 260-180, National Institute of Standards and Technology, Gaithersburg, MD, 2013], which accompanies the certified KLST.

Author : British Standards Institute Staff
Publisher :
Page : 28 pages
File Size : 21,76 MB
Release : 2009-02-28
Category :
ISBN : 9780580554667

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Metals, Charpy impact tests, Impact testing, Test equipment, Verification, Specimen preparation, Test specimens, V-shape, Notches, Pendulums, Dimensions, Testing conditions, Errors, Tolerances (measurement)

Author : Enrico Lucon
Publisher :
Page : 0 pages
File Size : 48,35 MB
Release : 2023
Category :
ISBN :

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The NIST Charpy Machine Verification Program is ready to introduce low-energy and high-energy certified specimens that can be tested at room temperature instead of -40 ℗ʻC, thus accommodating the requests of many customers during the past 35 years. An investigation aimed at providing a practical and technically sound definition of "room temperature" (barycentric value and tolerance) was conducted, by examining previously obtained Charpy energy transition curves for different energy levels, as well as by testing certified low-energy and high-energy specimens at 21 ℗ʻC (ambient temperature of the NIST Charpy Lab in Boulder, Colorado) and additional temperatures in the range 21 ℗ʻC ℗ł 5 ℗ʻC. Results have shown that for low-energy specimens, even within a relatively small 10 ℗ʻC range, the influence of test temperature on Charpy absorbed energy can be significant enough to cause "good" machines to fail the requirements of the ASTM E23 standard. Therefore, at this energy level, the allowable test temperature range must be restricted to 21 ℗ʻC ℗ł 1 ℗ʻC. For the other two energy levels (high and super-high), the influence of test temperature is small enough that the allowable temperature range can be expanded to 21 ℗ʻC ℗ł 3 ℗ʻC.

Author : C. N. MacCowan
Publisher : National Institute of Standards & Technology
Page : 369 pages
File Size : 15,63 MB
Release : 2004-04-01
Category : Metals
ISBN : 9780160680564

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Provides a compendium of various studies by NIST on Charpy impact test procedure and specimen preparation variables. Includes sections on: Overview and History; Materials and Heat Treatment; Specimen, Machine, and Procedure Effects; and Statistical Evaluations of Charpy Impact Data.

Author : DP. Vigliotti
Publisher :
Page : 4 pages
File Size : 48,10 MB
Release : 2005
Category : Charpy
ISBN :

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It has been thought that removing and replacing an in-tolerance 8-mm striker may affect the results of a Charpy test. This thought brought about a requirement in Standard Test Method E23 [1] that states that if a striker is removed and replaced on a Charpy machine, the indirect verification is void and a new verification test must be performed. Groups of NIST SRM 2092 and SRM 2096 specimens were tested on machines with three different striker-mounting designs. The specimens were tested with the striker removed and replaced between groups. The results of these tests support a change in the standard that can make removing and replacing the striker acceptable without performing a new indirect verification test.

Author : D. P. Vigliotti
Publisher : Forgotten Books
Page : 26 pages
File Size : 34,38 MB
Release : 2017-10-27
Category :
ISBN : 9780266831259

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Excerpt from Installing, Maintaining, and Verifying Your Charpy Impact Machine This Special Publication is a reprint of nist Technical Note 1500-8, a TN series started by the Materials Reliability Division. This TN series describes their division's significant research accomplishments in measurement technol ogy, reported so that producers and users of materials can improve the quality and reliability of their products. This particular Practice Guide provides practical advice on how to correct problems discovered during the testing of Standard Reference Materials 2092, 2096, and 2098 on Charpy impact machines. Although only a small percent age of machines fail to meet the requirements during their annual performance tests, the failure of a machine can have large economic implications to the machine's owners, and we try to assist in correcting the problems. From the study of the fractured specimens and test data that are returned to nist for evaluation, we have learned how to identify many of the common problems. Also, over the years, we have had discussions with thousands of engineers and technicians at these companies, and have learned the most efficient sequences for identifying the sources of the problem and for correcting them. Now, we have collected and organized the various problems and solutions in this Special Publication. We hope that you will find it useful for installing a new machine correctly, and then for preparing for the annual verification tests. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully; any imperfections that remain are intentionally left to preserve the state of such historical works.