Hot deformation behaviors and flow stress model of GCr15 bearing steel

The hot deformation behaviors of GCr15 bearing steel were investigated by isothermal compression tests, performed on a Gleeble-3800 thermal-mechanical simulator at temperatures between 950 ℃ and 1 150 ℃ and strain rates between 0.1 and 10 s-1. The peak stress and peak strain as functions of processing parameters were obtained. The dependence of peak stress on strain rate and temperature obeys a hyperbolic sine equation with a Zener-Hollomon parameter. By regression analysis, in the temperature range of 950-1 150 ℃ and strain rate range of 0.1?10 s?1, the mean activation energy and the stress exponent were determined to be 351kJ/mol and 4.728, respectively. Meanwhile, models of flow stress and dynamic recrystallization (DRX) grain size were also established. The model predictions show good agreement with experimental results.

Effects of deformation parameters on microstructure and mechanical properties of magnesium alloy AZ31B

Plastic deformation and dynamic recrystallization (DRX) behaviors of magnesium alloy AZ31B during thermal compression and extrusion processes were studied. In addition, effects of deformation temperature and rates on the microstructure and mechanical properties were investigated. The results show that the DRX grains nucleate initially at the primary grain boundaries and the twin boundaries, and the twinning plays an important role in the grain refinement. The DRX grain size depends on the deformation temperature and strain rate The average grain size is only 1 μm when the strain rate is 5 s-1 and temperature is 250 ℃. It is also found that the DRX grain can grow up quickly at the elevated temperature. The microstructure of extruded rods was consisted of tiny equal-axis DRX grains and some elongated grains. The rods extruded slowly have tiny grains and exhibit good mechanical properties.

The effect of solution constitute on continuous annealing steel plate recrystallization texture and stamping property

Recrystallization texture of steel plate is affected by substitution solid solution and interstitial solid solution.This article finished texture test and stamping test about low carbon aluminium killed steel,IF steel, phosphorus strengthen steel,Si -Mn -P strengthen steel.It can be found that all kinds of steel has similar intensity {111} texture in permanentφ= 45°about level 10.Interstitial solid solution steel had {101} texture and substitution solid solution steel had {112} texture.Based on recysstallization principle and stamping test, the effect of solution on recrystallization texture is discussed.It point out that interstitial solid solution impediment {111} texture forming and caused to {101} texture remained in steel.The phenomenon strengthen anisotropic property and reduction stamping property.Similar to substitution solid solution,it would impediment {111} texture too,but {101} texture changed to {112} texture.