Effect of Temperature on Cyclic Deformation Behavior of Zr-Sn-Nb Alloy

Effect of temperature on the cyclic deformation behaviors of Zr-Sn-Nb alloy (N18 alloy) at temperatures of 200, 300, 400 °C and the low cycle fatigue (LCF) behaviors at room temperature (RT) and 400 °C were investigated. The results indicate that LCF lifetime of N18 alloy decreases with increasing of the plastic strain range ?ep and obeys Coffin-Manson relation: ; At 400 °C, there appear sawtooth shaped hysteresis loops; Such phenomenon belongs to “Portevin-LeChatelier effect” (PLC effect). At 200, 300 and 400 °C, there are different cyclic characteristics. At elevated temperature, the fatigue fracture is characterized by dimples and secondary cracks, while mainly by secondary cracks at 400 °C.