On the mechanisms and mechanics of fracture toughness of a V-Cr-4Ti alloy

Effects of irradiation and crossrolling on fracture toughness-temperature c urves of the program heat of the V-4Cr-4Ti were evaluated. The alloy underg oes normal stress controlled cleavage fracture at low temperatures and duct ile tearing fracture at higher temperature. It appears that crossrolling lo wers the cleavage transition temperature. A critical stress-critical-stress ed area cleavage criterion is used to model toughness-temperature curves in the cleavage transition, including the effect of specimen size. Irradiatio n induced increases in the transition temperature are accurately predicted by an equivalent yield stress model. Ductile tearing toughness is also degr aded by irradiation, correlating with reduced uniform strains measured in t ensile tests. Large cleavage transition temperature shifts and ductile toug hness decreases may limit the application of V-4Cr-4Ti alloys for service i n low-to-intermediate temperature irradiation environments. (C) 2000 Elsevi er Science B.V. All rights reserved.