Study on warm forming effects of the axial-pushed incremental rolling process of spline shaft with 42CrMo steel

Abstract

The effects of the warm forming temperature on the axial-pushed incremental rolling process were investigated through finite element analysis and experimental studies. Firstly, the principle of warm axial-pushed incremental rolling process of spline shaft was introduced. Next, the material properties of 42CrMo steel at different forming temperatures were studied to discuss the effects of the warm forming temperature. Through finite element analysis, the simulations of the axial-pushed incremental rolling process were carried out to investigate the effects of the warm forming temperature on rolling forces. The results indicated that the axial and radial forces on the rolling dies were both reduced at the warm forming temperature. Finally, the experiment studies were carried out on a warm axialpushed incremental rolling equipment. The dimensional precision, microstructure, and hardness of the formed spline shafts at warm temperature were compared with those of the formed spline shafts at room temperature. The results indicated that the spline shafts, which were formed at the warm temperature, possesses of a good dimensional precision and excellent performance. The results in this paper demonstrated that the warm forming temperature has the positive effects on the performance improvement of the axial-pushed incremental rolling process of spline shaft.

Constitutive Equations for Describing the Warm and Hot Deformation Behavior of 20Cr2Ni4A Alloy Steel

“…At the early stage of the warm and hot forming process, there was the same plastic flow behavior due to work hardening. Namely, the stress increases sharply because of the rapidly increasing dislocation density and the limited dynamic softening mechanisms [43,44]. Next, the stress increased slowly until it reaches the peak stress, where there were the different true strain corresponding to the peak stress with increasing the temperature.…”

“…A linear search can be performed based on Figure 17 and it is finally determined the more reasonable approximations of the material parameters α, A, m When the material parameters are determined, the approximations of T * can be obtained by a line search method. Therefore, Equations (44) and (45) are developed:…”

“…When the material parameters are determined, the approximations of T* can be obtained by a line search method. Therefore, Equations (44) and (45) are developed:…”