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Measurement of Dynamic Impact Toughness on Impact-Tested Precracked Charpy Specimens



Enrico Lucon


The Fraunhofer Institute for Mechanics of Materials (IWM, Freiburg, Germany) and the Materials Testing Institute University of Stuttgart (MPA Stuttgart, Germany) have recently launched a joint collaboration project titled “Dynamic Mastercurves II” (MC-Dyn II). The project focuses on the measurement of the ductile-to-brittle transition toughness at impact loading rates by means of fatigue precracked and side-grooved Charpy-type specimens (PCC specimens). IWM and MPA invited NIST Boulder to contribute to the project by testing PCC specimens of a reactor pressure vessel (RPV) steel and determining the dynamic Master Curve reference temperature, T0,d, in accordance with ASTM E1921-14a. Tests at NIST were performed on an instrumented impact machine at 0 °C and with impact velocity v0 ≈ 1.21 m/s. The calculated reference temperature T0,d = -6.6 °C, corresponding to an average loading rate of 3.3 × 105 MPa√m/s, is in excellent agreement with the results previously published by MPA under similar conditions (T0,d = -7 °C). To the author’s knowledge, these are the first tests of this type ever performed at NIST Boulder.
NIST Interagency/Internal Report (NISTIR) - 8065
Report Number


Dynamic fracture toughness, dynamic reference temperature, impact loading rates, instrumented Charpy tests, Master Curve, precracked Charpy-type (PCC) specimens, reactor pressure vessel steel.


Lucon, E. (2015), Measurement of Dynamic Impact Toughness on Impact-Tested Precracked Charpy Specimens, NIST Interagency/Internal Report (NISTIR), National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed April 20, 2024)
Created June 18, 2015, Updated November 10, 2018