Microstructure evolution of three-roll skew-rolling formed hollow axles with uniform wall thickness

Abstract The uniform thickness hollow axle is one of the lightest weight axles in high-speed rail industry. It can effectively reduce unsprung mass and further improve train speed. Therefore, due to its importance significance, it crucial research develop axle. To understand microstructural evolution during three-roll skew-rolling (TRSR) forming, 30CrMoA alloy steel was used this study. A constitutive model established by SIMUFACT FORMING finite element software utilized simulate deformation, heat transfer, microstructure coupling TRSR. Via analyzing influence process parameters on average grain size, forming part at each deformation stage revealed. result shows that dynamic recrystallization rolled piece produces a fine structure process. refinement level enhanced with increase radial compression; size gradually increased from outer surface inner piece. At higher rolling temperature, found initial final were larger compared lower temperature. By increasing axial traction speed, not only time be shortened, but also appearance coarse grains avoided. mechanical properties improved.