Research on static recrystallization behaviour of pure molybdenum rods during forging

Abstract

In this work, thermal compression experiment of pure molybdenum rods with sintered density of 9.7–9.8 g cm−3 were performed on the Gleeble-1500D thermal simulator. The double-pass vacuum high-temperature compression test was carried out in a deformation temperature of 1200 °C–1350 °C, a strain rate of 3 s−1 and an interval time of 10–500 s. The stress-strain curve was obtained and analysed. The static softening rate was calculated by the 2% compensation method of yield stress, and the curve of that was fitted. The results show that the softening rate is proportional to the interval time and the deformation temperature. The static recrystallization activation energy and critical temperature of pure molybdenum rod is 583.79 kJ mol−1 and 1365 °C, respectively. Besides, the static recrystallization kinetics model and grain growth model of pure molybdenum rod was established and microstructure evolution of molybdenum was analysed during the deformation process.

Quantification of static softening process and its effects on work hardening characteristics of a typical high strength steel during multi-pass deformation

“…where q q 1 4 ~are material constants. Combining equations ( 7) and (8), equation ( 9) can be obtained as below: According to equation (9), the parameters in the static softening kinetics model can be calculated by multiple nonlinear regression. Equation (10) displays the calculated results.…”

“…For static softening behaviors, Ding et al [8] analyzed the effects of external stress on the static recovery (SRV) mechanism of A5083 aluminum alloy, and found that the effects of interrupted strain on SRV depend on the external stress during the inter-pass holding process. Zhang et al [9] studied the effects of deformation temperature and holding time on the static recrystallization (SRX) softening behaviors of pure molybdenum, and established a SRX kinetics model. Xu et al [10] explored the effects of different deformation and inter-pass holding parameters on the metadynamic recrystallization softening (MDRX) behaviors of V-containing 12Cr rotor steel, and constructed an MDRX kinetics model.…”