新型γ相强化CoNi基变形高温合金热加工性的研究

Study on The Hot Workability of New Type Strengthened CoNi-based Wrought Superalloy

本文以新型CoNi基变形高温合金为研究对象,采用扫描电镜(SEM)、电子背散射衍射电镜(EBSD)研究了实验合金的铸态组织、凝固偏析系数,并采用Gleeble热压缩实验模拟方法,获得合金的应力-应变曲线,进而构建了合金的热本构方程、热加工图。结果表明,铸态合金存在明显的凝固偏析,并且合金的热激活能为665kJ/mol。合适的热加工窗口为:热变形温度为1150℃,应变速率为0.001~0.01s和热变形温度为1100~1150℃,应变速率为0.006~0.1s。

In this paper,a novel CoNi-based deformed superalloy is used as the research object,and the as-cast microstructure and solidification segregation coefficient of the experimental alloy are studied by scanning electron microscopy(SEM)and electron backscatter diffraction electron microscopy(EBSD).And using the Gleeble thermal compression experiment simulation method,the stress-strain curves of the alloy are obtained,and then the thermal constitutive equation and thermal working map of the alloy are constructed.The results showed that the as-cast experimental alloy has obvious solidification segregation and the thermal activation energy of the experimental alloy is 665kJ/mol.And the suitable thermal processing windows are:the deformation temperature is 1150℃,strain rate is 0.001~0.01s^(-1),and the deformation temperature:1100~1150℃,strain rate:0.006~0.1s^(-l).