Effect of Charpy Striker Configuration on Low- and High-Energy NIST Verification Specimens
Enrico Lucon, Jolene D. Splett
Charpy machines can be equipped with strikers having two different configurations, corresponding to an edge radius of 2 mm or 8 mm. Both striker types are covered by ASTM E23 and ISO 148-1. The effect of striker type on Charpy absorbed energy has been extensively investigated in the past, and clear evidence has been published showing that when using 8 mm strikers, absorbed energy (KV) tends to increase for specimens with KV ≥ 200 J. In this paper, we investigate how striking edge radius affects certified values and uncertainties for National Institute of Standards and Technology (NIST) low-energy and high- energy verification specimens. Test data from two low-energy and two high-energy Charpy lots, analyzed in a statistically rigorous manner, were somewhat contradictory and led to the decision to separately certify low-energy and high-energy lots for use with 2 mm and 8 mm strikers. This agrees with previous findings by other NIST researchers, who recommended individual certifications for the two strikers at all energy levels.
and Splett, J.
Effect of Charpy Striker Configuration on Low- and High-Energy NIST Verification Specimens, Journal of Research (NIST JRES), National Institute of Standards and Technology, Gaithersburg, MD
(Accessed July 31, 2021)