Design of high-throughput double cone sample and grain structure evolution of GH4738 superalloy
In the field of superalloys,double cone sample has been widely used for high-throughput study on the relationship between processing parameters and microstructures.This article designed a double cone sample for GH4738 superalloy with a small effective strain rate((ε))fluctuations during compression through finite element simulation,and studied the impact of(ε)fluctuations in grain size and its temperature dependence.Moreover,the grain structure evolution of GH4738 superalloy was studied under the conditions of deformation temperatures of 1000-1160℃,strain rates of 2 s-1 and 14 s-1,and engineering strains of 30％,50％,and 70％.The results indicate that the fluctuation of(ε)strongly affects the grain size of the deformed alloy,and has a temperature dependence.The designed double-cone sample is beneficial for accurate research on the relationship between effective strain and grain structure.The hot compression experiments on the double cone sample show that discontinuous dynamic recrystallization is the main softening mechanism of GH4738 alloy.The hot working window for this alloy is the deformation temperature of 1030-1080℃,the strain rate of 14 s-1,and the engineering strain of 50％-70％.
GH4738 superalloyhigh throughputdouble cone samplehot working processgrain structure
NETL
NSTL
万方数据
