Abstract
The striker edge radii of instrumented Charpy impact testing machine standardized in ISO and ASTM are different. Both edge radii are standardized in JIS. However, the effects of striker edge radii on load-deflection curve and absorbed energy are still unclear.
In the present study, the effects of striker edge radii, which are standardized in ISO and ASTM, that is, striker edge radii of 2 mm and 8 mm, on load-deflection curve and absorbed energy in instrumented Charpy impact tests were investigated. There is no difference in values of absorbed energy per unit ligament area between the two different striker edge radii when the values are less than 0.75 J/mm2. However, striker edge radius according to ASTM, that is, a striker edge radius of 8 mm, is not appropriate for Charpy impact test method because the four, instead of three, point bending condition occurs during fracture process of specimen with high absorbed energy. The effect of brinell deformation on absorbed energy measured in both striker edge radii is very small.
