Analysis of the Microstructural Evolution of a Co–28Cr–6Mo Alloy during Hot Deformation

Abstract

The deformation behavior and microstructural evolution of a Co–28Cr–6Mo alloy during uniaxial compression tests have been analyzed. The tests are carried out at 1000, 1100, and 1200°C and strain rates of 1, 10, and 50 s^–1 using a Gleeble 3800 machine. Deformation resistance curves are obtained and the peak stresses are determined. The deformation behavior of the alloy is characterized by an increase in the flow stress with the strain rate and by its decrease with increasing temperature. The peak stress is recorded at higher strains when the temperature decreases or the strain rate increases. Deformation in the temperature range of 1000–1100°C is accompanied by strain hardening and partial dynamic recrystallization. After deformation at 1200°C, the microstructure of specimens consists of equiaxed recrystallized grains, and the microhardness does not depend on the strain rate. At the same time, an increase in the strain rate at 1000–1100°C leads to a slight decrease in the microhardness. The data obtained can be used for selecting deformation conditions for the Co–28Cr–6Mo alloy using industrial metal forming methods.