The hot deformation behavior of GH4945 superalloy was investigated by isothermal compression test in the temperature range of 1000--1200 ℃with strain rates of 0.001 10.000 s 1 toa total strain of 0.7. Dynamic recryst...The hot deformation behavior of GH4945 superalloy was investigated by isothermal compression test in the temperature range of 1000--1200 ℃with strain rates of 0.001 10.000 s 1 toa total strain of 0.7. Dynamic recrystallization is the primary softening mechanism for GH4945 superalloy during hot deformation. The constitutive equation is established, and the calculated apparent activation energy is 458. 446 kJ/moh The processing maps at true strains of 0.2, 0.4 and 0.6 are generally similar, dem- onstrating that strain has little influence on processing map. The power dissipation efficiency and in- stability factors are remarkably influenced by deformation temperature and strain rate. The optimal hot working conditions are determined in temperature range of 1082 -1131 ℃ with strain rates of 0.004--0.018 s-1. Another domain of1134--1150 ℃ and 0. 018 0.213s ^- can also be selected as the optimal hot working conditions. The initial grains are replaced by dynamically reerystallized ones in optimal domains. The unsafe domains locate in the zone with strain rates above 0, 274 s^- 1, mainly characterized by uneven microstructure. Hot working is not recommended in the unsafe domains.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos. 51601041and 51301085)
文摘The hot deformation behavior of GH4945 superalloy was investigated by isothermal compression test in the temperature range of 1000--1200 ℃with strain rates of 0.001 10.000 s 1 toa total strain of 0.7. Dynamic recrystallization is the primary softening mechanism for GH4945 superalloy during hot deformation. The constitutive equation is established, and the calculated apparent activation energy is 458. 446 kJ/moh The processing maps at true strains of 0.2, 0.4 and 0.6 are generally similar, dem- onstrating that strain has little influence on processing map. The power dissipation efficiency and in- stability factors are remarkably influenced by deformation temperature and strain rate. The optimal hot working conditions are determined in temperature range of 1082 -1131 ℃ with strain rates of 0.004--0.018 s-1. Another domain of1134--1150 ℃ and 0. 018 0.213s ^- can also be selected as the optimal hot working conditions. The initial grains are replaced by dynamically reerystallized ones in optimal domains. The unsafe domains locate in the zone with strain rates above 0, 274 s^- 1, mainly characterized by uneven microstructure. Hot working is not recommended in the unsafe domains.
