Effect of Thermal Cycling Rate on Thermo-Mechanical Cycling Strain Overlapping of a Fe-Ni-Cr Alloy

利用专门设计的热循环装置进行热机械循环迭加试验．研究表明热循环速率对热应变过程有密切依赖关系．快速热循环引起热应变途径偏离线性变化规律，并推迟了达到最大热应变过程．选择合理的最大热循环速率，以保证热循环应变与机械循环应变的线性变化关系．循环应力、应变及温度对时间的关系曲线表明，在热循环与机械循环同相与反相迭加条件下，在接近热循环上限值的高温范围出现热循环软化现象．这是两种热机械循环应力应变迭加方式所共有的特征行为．这一结果可由本文作者已发表的微观结构分析予以解释

Effect of Thermal Cycling Rate on Thermo Mechanical Cycling Strain Overlapping of a Fe Ni Cr Alloy

A special designed thermal cycling device was used to study the cycling stress strain behaviour of a Fe Ni Cr alloy under the superposition of thermal and mechanical cycling. The tests show that the thermal cycling strain process depends mainly on the thermal cycling rate, higher speed cycling can lead to the strain path apart from linearity and delay the process of approaching to its maximum value. A reasonable maximum rate for keeping linearity of strain path has been determined.The curves of cycling stress, strain and temperature versus time indicate that thermal cycling softening occurs in a range of higher temperature close to the maximum value of thermal cycling, which is a common characteristic for both in phase and out of phase strain superposition tests and can be explained by a previous report on the basis of microstructure analysis.