Abstract
? 2022 Elsevier B.V.Microstructure evolution and strengthening mechanisms of MP159 superalloy during room temperature rolling (RTR) and cryorolling (CR) were studied by using the XRD, EBSD and HRTEM methods. The results suggest that the grains size is finer and the density of dislocations is higher in the CR specimens with the same rolling reduction compared with the RTR specimens. Moreover, the deformation nano-twins and L-C locks can form in the RTR and CR specimens. The strengthening mechanism of the MP159 superalloy during RTR and CR processing is mainly ascribed to the dislocation strengthening, grain refinement strengthening and deformation nano-twins strengthening. After rolling deformation, a higher yield strength (YS) and ultimate tensile strength (UTS) were obtained in the CR specimens. Especially, at the rolling reduction of 48%, the YS and UTS of the CR specimens are 342 MPa and 314 MPa higher than that of the RTR specimens, respectively.
NSTL
Elsevier