摘要
研究了200、300、400℃温度下N18(NZ2)合金的循环变形行为,同时研究了室温和400℃低周疲劳行为。结果表明:N18(NZ2)合金低周疲劳寿命Nf随着塑性应变范围?εp的增加而降低,并遵循Coffin-Manson关系:Nfβ?εp=C;N18(NZ2)合金在400℃高温下,其循环滞后回线出现锯齿状波形,即出现Portevin-LeChatelier效应。且在200、300、400℃下,合金表现出与常温下不同的循环特性,呈现出一致循环硬化的现象;在高温下,N18(NZ2)合金疲劳断口局部出现韧窝型断裂,并出现细小的二次裂纹。大量二次裂纹的存在是400℃疲劳断口的主要特征。
Effect of temperature on the cyclic deformation behaviors of Zr-Sn-Nb alloy （N 18 alloy） at temperatures of 200, 300, 400 ℃ and the low cycle fatigue （LCF） behaviors at room temperature （RT） and 400℃ have been investigated. The results indicate that LCF lifetime of N18 alloy decreases with increasing of the plastic strain range Aep and obeys Coffin-Manson relation： Nβf△εp=C; At 400 ℃, there exist sawtooth shaped hysteresis loops, Such phenomenon belongs to ＂PortevinLeChatelier effect＂ （PLC effect）. At 200, 300 and 400 ℃, 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 ℃.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2008年第4期584-588,共5页
Rare Metal Materials and Engineering
基金
National Natural Science Foundation of China (50601024)
