We investigated the influence of the state of wear of Charpy machine anvils on test results by performing impact tests on NIST specimens of three energy levels with a machine equipped with new anvils (compliant with both ASTM E23  and ISO 148-2 ) and worn anvils (anvil corner radii and distance outside ASTM tolerances, but within ISO tolerances). The results obtained, statistically analyzed, unequivocally show that worn anvils tend to increase absorbed energy at all energy levels. On the other hand, data variability does not appear to be significantly affected by anvil wear. This study represents NIST contribution to an international effort spearheaded by the Japan Iron and Steel Federation Standardization Center (Tokyo, Japan).
Journal of Research (NIST JRES) -
Absorbed energy, anvil radius, ASTM E23, Charpy, ISO 148, machine anvils, span, wear.