Dynamic Initiation Fracture Toughness of a Pressure Vessel Steel in the Transition Region

Abstract

The dynamic fracture toughness of an ASTM A533, Grade B steel plate was determined at several temperatures in the ductile-brittle transition region. Crack-tip loading rates ranged from approximately 103 to 105 MPa√m/s. The fracture toughness was shown to decrease with increased loading rate. The dynamic fracture toughness was compared with results from previous investigations and it was shown that the decrease in toughness due to increased loading rate at the highest test temperature was not as severe as reported in previous investigations. It was also shown that the reference temperature, T0, was a better index of the fracture toughness vs. temperature relationship than the nil-ductility temperature, RTNDT for this material.