Effects of the Striking Edge Radius on the Charpy Impact Test

Naniwa, T; Shibaike, M; Tanaka, Michihiro; Tani, Hideki; Shiota, Koji; Hanawa, N; Shiraishi, Toshiyuki

doi:10.1520/stp24139s

Cited by 10 publications

(9 citation statements)

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“…As far as other Charpy parameters are concerned, most authors agree that lateral expansion values from 2 mm-strikers are generally higher, whereas no differences can be observed in terms of shear fracture appearance (Naniwa et al 1990;Nanstad and Sokolov 1995;McCowan et al 2000).…”

Section: Introductionmentioning

confidence: 95%

“…Numerous published studies (Towers 1983;Revise 1990;Fink 1990;Naniwa et al 1990;Ruth 1995;Nanstad and Sokolov 1995;Tanaka et al 1995;Siewert and Vigliotti 1995;McCowan et al 2000) have investigated the effect of the striking edge radius on the results of "conventional" (i.e. non-instrumented) Charpy tests, in terms of absorbed energy KV, lateral expansion and shear fracture appearance.…”

Section: Introductionmentioning

confidence: 99%

“…Limited information, and mostly of qualitative rather than quantitative nature, is available in the literature on the effect of striking edge radius on instrumented Charpy data (Naniwa et al 1990;Nanstad and Sokolov 1995;Tanaka et al 1995;Morita and Kobayashi 2004).…”

Section: Introductionmentioning

confidence: 99%

“…This feature, which is absent in tests performed using a 2 mm-striker, is caused by the interaction between the heavily deformed specimens and the corners of the 8 mm-striker just before the sample is released (Schuurmans et al 2008). It is considered to be one of the main contributions to the large difference between strikers at high energy levels, together with the increased friction between specimen and anvils (Naniwa et al 1990;Ruth 1995;Nanstad and Sokolov 1995;Tanaka et al 1995;Siewert and Vigliotti 1995;McCowan et al 2000).…”

Section: Introductionmentioning

confidence: 99%

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Influence of striking edge radius (2 vs. 8 mm) on instrumented Charpy data and absorbed energies

Lucon

2008

Int J Fract

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The most commonly used test standards for performing Charpy impact tests (ISO 148 and ASTM E 23) envisage the use of strikers having different radii of the striking edge, i.e. 2 mm (ISO) and 8 mm (ASTM). The effect of striker geometry on Charpy results was extensively studied in the past in terms of absorbed energy measured by the machine encoder, but few investigations are available on the influence of striker configuration on the results of instrumented Charpy tests (characteristic forces, displacements and integrated energy). In this paper, these effects are investigated based on the analysis of published results from three interlaboratory studies and some unpublished Charpy data obtained at SCK·CEN. The t-test was used for establishing the statistical significance of the observed effects. The instrumented variables which are the most sensitive to the radius of the striking edge are the maximum force and its corresponding displacement, with 8 mm-strikers providing systematically higher values. The effect on general yield forces, on the other hand, is less consistent and more difficult to rationalize, although 2 mm-strikers generally tend to deliver higher values. Absorbed energies, obtained both from the instrumented trace and from the pendulum encoder, are almost insensitive to the type of striker up to 200 J. For higher energy levels, the values obtained E. Lucon (B) SCK·CEN, from 8 mm-strikers become progressively larger. Data scatter is generally higher for 2 mm-strikers.

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Section: Introductionmentioning

confidence: 95%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Influence of striking edge radius (2 vs. 8 mm) on instrumented Charpy data and absorbed energies

Lucon

2008

Int J Fract

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“…The data from Ref. 4, however, shown in Fig. 3(b), appear to show a general deviation from equivalence with the 2-mm striker showing a tendency for greater expansion.…”

Section: Towers [3] Tested Verification Specimens From the Army Mechamentioning

confidence: 77%

Charpy Impact Test Results on Five Materials and NIST Verification Specimens Using Instrumented 2-mm and 8-mm Strikers

Nanstad

Sokolov

1995

Pendulum Impact Machines: Procedures and Specimens for Verification

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The Heavy-Section Steel Irradiation Program at Oak Ridge National Laboratory is involved in two cooperative projects, with international participants, both of which involve Charpy V-notch impact tests with instrumented strikers of 2-mm and 8-mm radii. Two heats of A 533 grade B class 1 pressure vessel steel and a low upper-shelf (LUS) submerged-arc (SA) weld were tested on the same Charpy machine, while one heat of a Russian Cr-Mo-V forging steel and a high upper-shelf (HUS) SA weld were tested on two different machines. The number of replicate tests at any one temperature ranged from 2 to 46 specimens. Prior to testing with each striker, verification specimens at the low, high, and super high energy levels from the National Institute of Standards and Technology (NIST) were tested. In the two series of verification tests, the tests with the 2-mm striker met the requirements at the low and high energy levels but not at the super high energy. For one plate, the 2-mm striker showed somewhat higher average absorbed energies than those for the 8-mm striker at all three test temperatures. For the second plate and the LUS weld, however, the 2-mm striker showed somewhat lower energies at both test temperatures. For the Russian forging steel and the HUS weld, tests were conducted over a range of temperatures with tests at one laboratory using the 8-mm striker and tests at a second laboratory using the 2-mm striker. Lateral expansion was also measured for all specimens and the results are compared with the absorbed energy results. The overall results showed generally good agreement (within one standard deviation) in energy measurements by the two strikers. Load-time traces from the instrumented strikers were also compared and used to estimate shear fracture percentage. Four different formulas from the European Structural Integrity Society draft standard for instrumented Charpy test are compared and a new formula is proposed for estimation of percent shear from the force-time trace.

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The Influence of Instrumented Striker Configuration on the Results of Dynamic Toughness Testing

Lucon

2008

Journal of ASTM International

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Several studies are available on the influence of the edge radius of instrumented strikers (ASTM — 8 mm or ISO — 2 mm) on the results of both non-instrumented and instrumented Charpy tests. This paper investigates the effect of using either a 2 mm or a 8 mm striker when performing dynamic toughness tests at impact loading rates on precracked Charpy specimens. Existing data from tests run in the ductile-to-brittle region (dynamic Master Curve reference temperature) and in the upper shelf regime (ductile initiation fracture toughness and crack resistance curves) have been analyzed. The results show that 2 mm strikers tend to yield lower cleavage fracture toughness in the transition region (although the effect cannot be considered statistically significant), whereas the influence of striker configuration is negligible in the upper shelf regime when data are generated using the low-blow multiple-specimen technique.

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Effects of the Striking Edge Radius on the Charpy Impact Test

Cited by 10 publications

References 0 publications

Influence of striking edge radius (2 vs. 8 mm) on instrumented Charpy data and absorbed energies

Influence of striking edge radius (2 vs. 8 mm) on instrumented Charpy data and absorbed energies

Charpy Impact Test Results on Five Materials and NIST Verification Specimens Using Instrumented 2-mm and 8-mm Strikers

The Influence of Instrumented Striker Configuration on the Results of Dynamic Toughness Testing

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