Hot deformation behavior and critical condition of dynamic recrystallization of GH4710 alloy prepared by ingot-extrusion

Isothermal compression tests of ingot-extruded GH4710 alloy were conducted within the temperature range of 1050 ℃ to 1150 ℃ and at strain rates ranging from 0.01 s-1 to 5 s-1. The analysis focused on the flow behavior and the critical condition for dynamic recrystallization (DRX). The stress-strain curves exhibited four stages: strain hardening, abnormal softening, rheological softening, and typical DRX (TDRX). Precise determination of the critical strain (\({\varepsilon }_c\)) associated with the initiation of abnormal softening and TDRX was based on the inflection points in the work hardening rate curves (\(\theta\) - \(\sigma\)). Furthermore, the constitutive equations for abnormal softening and TDRX initiation were established.