抄録
Rapid-load plane-strain fracture toughness was evaluated on type A508 class 3 steel using a high loading rate tensile machine. Tests were performed according to ASTM E399-83 ANNEX 7 in order to examine the effects of specimen thickness on initiation toughness KQ and to clarify the significance of the fracture time limitation. The results of this study show that the variation in measured KQ values could be reduced by increasing the specimen thickness and the present size requirements of B ≥2, 5(KQ/σyD)2 are marginally sufficient to obtain valid plane-strain fracture toughness KIC(t) values, and that the fracture time limitation of ANNEX 7 is not substantial requirement but dependent largely on the accuracy of instrumentation of the testing system.
