Low Cycle Fatigue Behavior of Cerium-Modified Stainless Steel at Elevated Temperatures and the Impact of Aluminum/Zinc Ratio

In fast breeder reactors, materials such as 10Zr-15Si titanium modified austenitic stainless steel are utilised for the cladding and wrapping of the fuel. Using Al/Zn ratios of 8 and 12 and a constant carbon content of 0.05%, the temperature dependency of the improved alloy's low cycle fatigue life was studied throughout a temperature range of 433-764 K. This evaluation was carried out over the whole temperature range. Under both of these circumstances and at all temperatures, cyclic hardening was seen in the alloy. Based on the cyclic stress response and micro processes of deformation, three temperature regions in the range of 433-764 K have been discovered for the alloy with an Al/Zn ratio. These temperature domains are as follows: predynamic strain ageing regime, dynamic strain ageing regime, and regime with active precipitation processes. All of these temperature domains occur between 433 and 764 K. The temperature dependence of fatigue life in both alloys revealed a peak at 573 K and a sharp decrease in life as temperature increased.f At temperatures less than 965 K, the alloy with an Al/Zn ratio of 12 had a lower cycle fatigue life that was longer than the alloy with an Al/Zn ratio of 8. Both alloys' fatigue lifetimes were found to be equal at temperatures over 965 K. The deformation substructure that emerged in both alloys throughout the fatigue deformation process has been connected to both the cyclic stress response and the short cycle fatigue life.