Abstract:Large and long thick-walled hollow shafts are the key parts of industry equipments, which are formed by the multi-wedge cross wedge rolling (MCWR) in this paper. First, the deflection angle equations of side-wedges applied at the multi-wedge cross wedge rolling of hollow shafts were derived, which lay important foundation for designing the MCWR mold. Second, It is found that the spreading angle's impacts on single-wedge cross wedge rolling of thick-walled hollow shaft-part. And, compared to roll small diameter of hollow shaft, the ellipiticity of the large and long thick-walled hollow shaft could be controlled, the selection range could be extended. At the same time, it was also found that the ellipiticity was could also be controlled by empty top surface of the mold. At last, the FE model of double-wedge cross wedge rolling of large and long thick-walled hollow shaft was established. The forming process was simulated, and the ellipiticity of symmetrical cross-section was monitored. The ellipiticity of large and long thick-walled hollow shaft was controlled, the ellipiticity of symmetrical cross-section is 4.98%, the experimental ellipiticity is 5.56%. The research results indicate that it is feasible to produce large and long thick-walled hollow shafts with double-wedge Cross Wedge Rolling.