Fracture toughness evaluation of a H.S.L.A. steel

The fracture toughness, JIc of a 3.5 Ni–Cr–Mo–V steel has been measured using the ASTM method. The results have been used to predict the stress intensity factor, KIc from the relationship between linear elastic and elastic–plastic fracture parameters. These predicted values were compared with KIc values obtained from empirical equations based on valid KIc tests, involving the Charpy upper shelf energy. It was found that the ASTM method for measuring JIc led to conservative estimates of KIc.