Numerical and experimental analysis of deformation behaviors and microstructure evolution in the thread rolling process

The thread rolling process is an advanced bulk forming process to produce thread parts. The superior performance of the formed thread parts as compared to those manufactured by the cutting process closely relates to the microstructure of the formed thread parts. In this study, a finite element model (FEM) was established to analyze the deformation characteristics in the thread rolling process. The viscoplastic self-consistent (VPSC) simulation was coupled with FEM to investigate the texture evolution and distribution. Besides, the thread rolling experiments were carried out, and the microstructure on different positions of formed thread parts was observed to analyze the characteristics of the microstructure and verify the simulation. Simulation and experimental results showed that the materials were mainly stretched on the bottom and top of formed thread parts, while on the flank they were obviously rotated. On the bottom and the flank of the formed thread parts, the grains were severely refined, and an obvious γfiber texture was formed. On the top of the formed thread part, {001} <110> texture was observed.