The flow behavior modeling of as-extruded 3Cr20Ni10W2 austenitic heat-resistant alloy at elevated temperatures considering the effect of strain

Abstract

In order to investigate the compressive deformation behavior of 3Cr20Ni10W2 alloy, a series of isothermal upsetting experiments were carried out in the temperature range of 1203-1403 K and strain rate range of 0.01-10 s -1 on a Gleeble-1500 thermo-mechanical simulator. The results indicate that the flow stress initially increases to a peak value and then decreases gradually to a steady state. The characteristics of the curves are determined by the interaction of work hardening (WH), dynamic recovery (DRV) and dynamic recrystallization (DRX). The flow stress decreases with increasing temperature and decreasing strain rate. The relationship between microstructure and processing parameters is discussed to give an insight into the hot deformation behavior of 3Cr20Ni10W2 alloy. Then, by regression analysis for constitutive equation, material constants (n, α, β, A and Q) were calculated for the peak stress. Further, the constitutive equation along the flow curve was developed by utilizing an eighth order polynomial of strain for variable coefficients (including n, α, Α and Q). The validity of the developed constitutive equation incorporating the influence of strain was verified through comparing the experimental and predicted data by using standard statistical parameters such as correlation coefficient (R) and average absolute relative error (AARE) that are 0.995 and 4.08% respectively.

Influence of incremental pre-strain on corrosion behavior of Al-Zn-Mg powder metallurgy alloy during hot forging

“…[17][18][19] Next, in the second stage, the dynamic softening process then started to operate due to dynamic recrystallization (DRX) and dynamic recovery (DRV), and the peak stress occurred. As shown by Quan et al 20 in stage 3, two distinct plot changes may be noticed. At 300°C, constant high PS values indicate a balancing between work hardening (WH) and dynamic softening.…”

Hot deformation behavior and dynamic recrystallization constitutive modeling of Al–Cu–Mg powder compacts processed by extrusion at elevated temperatures

“…In the third stage, two different types of plot variations can be observed as depicted by Quan et al. 39 (i) maintaining high PFS values that indicate the balance between WH and dynamic softening (450°C, 500°C and with all strain rates), (ii) flow stress drops continuously after reaching PFS where the dynamic softening dominates over WH (550°C and at all strain rates). WH, DRV, and DRX play a vital role in microstructural changes of materials and their mechanical properties, which are explained in the later stages of this work.…”

“…Therefore, the flow stress has been increased with the increasing strain rate, which might be attributed to increasing dislocation density. 39 In contrast, the deformation time for dynamic softening is high at low strain rates, which lead to the annihilation of dislocation (Figure 7(a)) so that the recrystallization grain size is high at lower strain rate. At the strain rate of 0.1 s À1 and deformation temperature of 550 C, the microstructure shows complete recrystallized microstructure with homogenous grain formation.…”