Feasibility study on thinning and thickening of thin-walled pipe fittings in three-roll skew rolling

摘要

Aiming at the existing problems, e.g. cracking, many forming passes, difficult control of dimensional accuracy, in thin-walled pipe fittings hot extrusion forming process, a innovative forming on thinning and thickening of thin-walled pipe fittings by three-roll skew rolling with a pair of molds is being proposed in this paper. Based on the analysis of the movement principle of the three-roll skew rolling hollow reduction process, the three-roll diameter reducing and end-thickening forming of thin-walled pipe blank with 1.5mm wall thickness is simulated by Simufact Finite Element software. The law of metal flow, strain field and rolling force are analysed, and the forming mechanism is clarified. The product meeting the production specifications is obtained by comparing the simulation results of the end wall thickness distribution and the wall thickness of pipe forming. The results show that the diameter reducing and end-thickening forming process of thin-walled pipe fittings by three-roll skew rolling is feasible. This study lays a theoretical foundation and new idea for the diameter reducing and end-thickening high-efficiency precision forming of thin-walled pipe fittings such as aircraft control rods.