Hot deformation behaviors and optimization of processing parameters for Alloy 602 CA

The hot deformation behavior of a new alloy, Alloy 602 CA is investigated by means of a series of compression tests. The stress-strain behavior, microstructure evolution and processing parameters optimization are studied carefully. Based on the measured stress-strain data, a two-stage method and a modified Arrhenius constitutive equation, which fit the experimental stress-strain curves well, are established for future numerical simulation. The final microstructure of the material after hot deformation shows a strong correlation with the processing parameters. During hot deformation, the main restoration mechanism for Alloy 602 CA is discontinuous dynamic recrystallization (DDRX) and dynamic recovery (DRV) accompanied by continuous dynamic recrystallization (CDRX). With temperature increasing and strain rate decreasing, the dynamic recrystallization (DRX) fraction increases. Grains begin to grow after DRX finishes at 1100 degrees C, 0.01 s(-1). A processing map based on dynamic materials model (DMM) is built and divided into four domains containing three feasible domains and an instable domain. The preferred domain to achieve uniform fine grains ranges from 1080 degrees C to 1100 degrees C, 0.01 s(-1) to 0.1 s(-1). (C) 2018 Elsevier B.V. All rights reserved.