GH4145合金热变形行为研究

Study on Hot Deformation Behavior of GH4145 Alloy

对GH4145镍基高温合金在温度为950~1200℃、应变速率为0.5~50 s-1范围内的热变形行为进行了系统研究,分析了合金的真应力-真应变曲线、变形组织,建立了合金热变形本构方程和加工图。结果表明:应变在0.3左右流变应力达峰值,应变大于0.7时,流变应力进入稳态阶段;相同应变条件下,晶粒尺寸随应变速率增加而减小,功率耗散因子峰值在应变速率50 s-1、温度1100~1150℃范围内;合金稳态成形温度应大于1050℃。

This work conducts a systematic study to the hot deformation behavior of Ni-based superalloy GH4145 over the range of 950~1200 ℃, 0.5~50 s-1, and then develops the constructive equation and processing map of this alloy based on the analysis of the true stress-true strain curve and deformation microstructure. The result shows that the flow stress peaks at strain 0.3 and the plastic deformation entre the steady stage when the strain is over 0.7. The average grain size decreases with the increasing of strain rate. The power dissipative factor peaks at 50 s-1 over the range of 1100~1150 ℃. It can be concluded from the analysis above that the alloy GH4145 should be deformed over 1050 ℃.