Comparison among Domestic and Overseas Standards of Instrumented Impact Test of Metallic Materials

The main differences of instrumented impact testing standards for EN ISO 14556:2015, GB/T 19748-2005 and ASTM E2298-15 were compared, especially the equipment requirements, applicable sample size and type, determination of force-displacement type, determination of percent shear area on fracture surface and so on, the new content in GB was also explained. The results show that ASTM standard has higher instrumentation requirements, but the feasibility of ISO and GB is better, ISO and ASTM standards include the testing part of miniaturized Charpy V-notch specimens, which has enriched contents of test. But the actual testing results show that the force-displacement curve of small size sample is less stable than the standard sample of 10 mm×10 mm×55 mm, the choice of formula and characteristic coefficient K have great influence on the determination of the percent shear area on fracture surface, the new definition of crack forming energy W_i and crack propagation energy W_p were added into GB, so that the back section of force-displacement characteristic curve was further refined, which has certain theoretical research value.