Metadynamic Recrystallization Behavior of Cr-Ni-Mo Alloy Steel

Abstract

In order to study the metadynamic recrystallization behavior of 34CrNi3MoV steel, a double-pass isothermal compression experiment and a single-pass thermal interval experiment were designed and conducted to obtain the stress–strain curves under different deformation conditions and to explore the action law of deformation parameters during the compression process. The softening rate was calculated by the compensation method, and the grain size in the recrystallization region was measured. Based on the obtained data, the effects of deformation temperature (T), interval time (t), and strain rate (ε˙) on the softening rate and grain size of 34CrNi3MoV steel during metadynamic recrystallization were analyzed. The results show that increasing the deformation temperature, extending the interval time, and increasing the strain rate are all beneficial to the improvement of the metadynamic recrystallization softening rate and that fine and uniform new grains can be obtained under a high strain rate. However, in high-temperature conditions, mixed crystallization can easily occur, which is not conducive to grain refinement. Based on the true stress–strain data and experimental data on the grain size, a relevant model for metadynamic recrystallization of 34CrNi3MoV steel was established using mathematical analysis of regression equations. The average relative error AARE between the constructed dynamic model and the grain size model and the experimental results are 6.48% and 1.30%, respectively. This indicates that the model has high predictability.

Keywords

• Cr-Ni-Mo steel
• metadynamic recrystallization
• softening rate
• kinetics models
• grain size