The hardening and embrittlement of steel by irradiation with neutrona

Abstract

Abstract The tensile yield and fracture strengths of a structural steel have been measured before and after irradiation with neutrons. The fracture strength increases with irradiation at the same rate as the yield strength and the embrittlement cannot be ascribed to a loss of cohesive strength. Measurements have been made of the effects of grain size and testing temperature on the yield and fracture strengths; applied to Petch's equation they show that the radiation hardening is caused essentially by an increase in ‘frictional’ resistance in the slip planes, such as would be produced by dispersed islands of radiation damage, and that the cohesive strength of the lattice and the dislocation locking stress are not detestably changed by the irradiation. Notched-impact tests have also been made to show the embrittling effect of the irradiation.