Publications Details

Effects of sample size and loading rate on the transition behavior of a DCI alloy

Salzbrenner, R.; Crenshaw, T.B.

The measurement and understanding of the fracture toughness of ductile cast irons, DCI, are critical to the analysis of nuclear transportation casks made from these alloys. Cask containment must be assured for all loading events from normal handling to accidents during which high loads can be delivered at elevated rates. Cask walls are commonly in the range of 20 to 50 cm thick (or greater) in order to provide requisite nuclear shielding, and this requires that associated mechanical constraint effects must be considered. At elevated temperatures (i.e., in the vicinity of ambient) DCI behaves in an elastic-plastic manner, even for large section sizes (B>20 cm) and moderately high loading rates. However, as the temperature is lowered or the loading rate is increased, ferritic DCI alloys exhibit a relatively sharp transition to linear elastic behavior, with a significant decrease in the fracture toughness. The fracture toughness of a DCI alloy has been measured using linear elastic and elastic-plastic experimental techniques. Measurements have been made as a function of temperature, loading rate and section size. The loading rates span the range which a cask could experience during normal transport and handling, as well as accident events. 15 refs., 7 figs., 4 tabs.