Correlation between charpy-V notch impact energy and KJIC of ferrite ductile iron in the transition-temperature region

Abstract Fracture toughness is an important index for the structural integrity assessment of ductile iron spent fuel transportation casks. Fracture toughness tests require a long test period, high cost, and difficult operation. Therefore, the Charpy V-notch impact energy value (KV) is considered to predict fracture toughness (K JIC ).In this study, Charpy V-notch impact tests(−80 °C, −60 °C, −40 °C, −20 °C, 0 °C, 20 °C, 40 °C, 60 °C, 80 °C) and fracture toughness tests(−60 °C, −40 °C, −20 °C, 0 °C, 20 °C) of ferrite ductile iron(FDI) were carried out. A K JIC -KV model for FDI in the transition temperature region was proposed, taking into consideration the influence of test temperature(T) and yield strength( σ YS ), then the proposed model was compared to the K IC -KV empirical equations of steel in the transition-temperature region, using the test data of FDI. The results indicate that the K JIC -KV model proposed in this work is more accurate and applicable for predicting fracture toughness values in the transition-temperature region than others, the residual between the estimated value of the K JIC -KV correlation model (K JIC-E ) and the experimental value of K JIC (K JIC-T ) was less than 4.1 MPa·m 0.5 , and the error was less than 5%.