Thermal deformation behavior and microstructure evolution of GH141 superalloy during double-cone gradient compression

Abstract

Thermal deformation behavior and microstructure evolution of GH141 alloy were researched efficiently by a high-throughput double-cone (DC) gradient compression to provide support for the formulation of forging process and gaining ideal microstructure. A wide gradient equivalent strain distribution was obtained for the DC specimens under different compression temperatures. The flow stress during DC gradient compression increased rapidly at the beginning of deformation, then decreased rapidly after reaching a certain peak, and finally tended to steady with the increase of deformation. The obvious gradient microstructure was obtained when compressing at 1050 °C, 1075 °C and 1100 °C. But when compressing at 1125 °C and 1150 °C, the grains were uniformly equiaxed inside the DC specimens with gradient strains. Continuous dynamic recrystallization (CDRX) and discontinuous dynamic recrystallization (DDRX) existed simultaneously in the DC specimen compressed at 1050 °C. The dynamic recrystallization (DRX) mechanism shifted towards the DDRX with the rising of compression temperature. In short, increasing the deformation temperature can obtain uniform equiaxed grain microstructure inside a GH141 superalloy with different strains, which has an important guiding role the fabrication of GH141 ring rolled parts.