Abstract:The effect of cooling rate after β phase heat treatment on the nodular corrosion resistance of Zircaloy-4 specimens was investigated by autoclave tests in superheated steam at 500 ℃/10.3 MPa. The nonuniform nodular corrosion resistance of Zircaloy-4 plates produced in factory was also studied. The results indicate that, the precipitation of Zr(Fe,Cr)2 second phase particles along α-Zr grain boundaries occurred with the decrease of cooling rate after β phase heating. It means that supersaturated solid solution contents of Fe and Cr alloying elements in α-Zr matrix were reduced with the decrease of cooling rate after β phase heating, and the nodular corrosion resistance of Zircaloy-4 specimens after cold rolling and recrystallization annealing was also degraded. It is considered that the variance of cooling rate at different parts of the same slab during β phase quenching in industrial production was contributed to the nonuniform nodular corrosion resistance of Zircaloy-4 plates.