Study on transverse wall thickness accuracy of tube rolled by automatic plug mill

In view of serious uneven transverse wall thickness of thin walled stainless steel tube rolled by automatic plug mill，the automatic tube rolling process of X10CrNiTi18 stainless steel tubes with typical specification of 112mm×4.5mm was numerically simulated by using 3D finite element analysis software Simufact. The influence of different roll pass structure parameters, different mandrel lubrication state, roll pass wear and eccentricity of pierced shell on transverse wall thickness accuracy of automatic rolling tube was analyzed. The results show that as the friction coefficient of the mandrel increases, the accuracy of transverse wall thickness of the rolled tube deteriorates obviously. The hollow tube rolled by eccentric pierced shell is still eccentric, and it shows that the elongation rolling has a limited ability to correct the eccentric wall thickness of the pierced shell. With repaired the worn pass, the unevenness of the transverse wall thickness of the rolled tube increases using the negative mandrel compensation rolling compared with the increase of mandrel diameter. The average transverse wall thickness of the rolled tube is closer to the target wall thickness by using three section arc groove, and the transverse wall thickness unevenness decreases from 13.55% of the original groove to 9.94%, and the transverse wall thickness accuracy is obviously improved.