摘要
研究了抗热腐蚀铸造镍基高温合金K52在室温和900℃的低周疲劳行为.对循环应力-应变数据和应变-疲劳寿命 数据进行了分析,给出了K52合金在此温度下的疲劳参数.合金的循环应力响应行为在室温下呈现循环硬化,而在900℃时则呈 现循环软化,原因在于循环形变过程中位错之间以及位错与析出相之间的相互作用.疲劳断口宏观和微观分析表明:裂纹主要萌生 于试样表面或靠近表面的缺陷处;裂纹形成后垂直于加载轴方向扩展,试样呈穿晶断裂.
Low cycle fatigue (LCF) behaviors of cast nickel-base superalloy K52 at different temperatures were investigated, and the fatigue parameters were given by analyzing its cyclic stress-strain curves and strain-life curves. Cyclic stress response curves show that the alloy exhibited cyclic hardening and softening behaviors at room temperature and 900 degrees C, respectively. OM and SEM observations indicated that LCF cracks initiated predominantly on the surface of specimen or at the near-surface defects. Once initiated, cracks would propagate perpendicularly to the loading direction and the specimens exhibited transgranular fracture.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2005年第4期357-362,共6页
Acta Metallurgica Sinica
关键词
K52合金
低周疲劳
循环应力响应
疲劳裂纹
K52 superalloy
low cycle fatigue
cyclic stress response
fatigue crack
