Constitutive Equation and Hot Deformation Behavior of SLM-GH3536 Alloy

The hot deformation behavior and microstructure evolution of superalloys may occur in the special service environment, which directly affects their performance. To explore the response of GH3536 alloy prepared by selective laser melting (SLM) at high temperature, hot compression tests were carried out to investigate the mechanical properties of SLM-GH3536 alloy at different conditions. The deformation temperature ranges from 900°C to 1050°C, and the strain rate ranges from 0.01 s⁻¹ to 10 s⁻¹. The results show that the flow stress and deformation mechanism are significantly influenced by the deformation conditions. The relationship between deformation conditions and flow stress is established by applying an Arrhenius-type constitutive equation. The flow stress was further predicted by using the strain compensation constitutive equation with high accuracy (AARE = 7.10%). The microstructure observation revealed that temperature has a greater influence on the degree of dynamic recrystallization (DRX). Two DRX mechanisms are analyzed. Discontinuous DRX is the primary deformation mechanism, which is accelerated with increasing temperature and strain rate, whereas continuous DRX is a cooperative deformation auxiliary mechanism, which is facilitated as temperature increases and strain rate decreases.