The Ductile Crack Growth Effect on the Temperature Dependence of CleavageFracture Toughness

摘要

The basic regularities of cleavage fracture after ductile crack growth are studied on the basis of a probabilisticmodel for cleavage fracture and deterministic model for ductile fracture proposed by the authors earlier. Investigationsare performed as applied to a 2Cr-Ni-Mo-V reactor pressure vessel steel in the initial (as-produced) and embrittledstates. For various temperatures, the dependencies of brittle fracture probability on stress intensity factor and the ductiletearing are calculated. For various states of a material, the temperature dependencies of cleavage fracture toughness arepredicted with and without regard for ductile crack growth. The basic factors controlling the above dependencies areanalyzed. The calculated results obtained are compared with test results of CT specimens.