Microstructural evolution and kinetic characteristics during metadynamic recrystallization in a Ni-Cr-Mo alloy

The metadynamic recrystallization (MDRX) characteristics of a Ni-Cr-Mo alloy are investigated using the double-pass thermal compression tests. The impacts of double-pass compression parameters on the kinetic features and microstructural changes are clarified. Results signify that the MDRX softening behaviors are remarkably accelerated with increasing of compression temperature, first-pass strain or strain rate. The bulging of the MDRX grain boundary and the annihilation/interaction of substructures become weaken at low compression temperature or small first-pass strain, enhancing the grain refining during MDRX. However, the MDRX grains coarsen rapidly with decrease of strain rate. Based on the comprehensive impact of double-pass compression parameters on softening fraction and grain size, the MDRX kinetic model and MDRX grain size model are developed. The predicted results are well matched the experimental data, which suggests that the established models can precisely characterize the changes of softening characteristics and grain size of the researched alloy during MDRX.(c) 2022 Elsevier B.V. All rights reserved.