Crack-Starter Impact Bend Test

Abstract

To investgate the difference in crack sensitivity, the Crack-Starter Impact Bend Test was applied to fourteen steels consisting of two high tensile, and ten mild steels, namely four killed, three semi-killed, and three rimmed steels.
The high tensile steels showed the best result, being followed by in the order of killed, semi-killed and rimmed steels.
The 2kg-m/cm² transition temperature in this test was found to have linear corelation with the 15 ft-lb transition temperature in standard V Charpy test. And the fracture of Charpy test specimen at the temperature of 2kg-m/cm² transition in this test showed larger crystallinity than 85 percent.
Particulars were given on initiation and propagation of crack in some steels and fractures of twice blow test were observed.