Research On Mechanism And Control Of Axial Deviation In Heavy Shell Rolling

Hot rolling forming technology for large cylindrical shell has attracted much attention in the heavy equipment manufacturing field due to its outstanding advantages,such as short process,low energy consumption,high precision,high production efficiency and so on.However,as a new forming technology for large cylinder forgings,there are still many key problems to be solved,and the axial deviation is one of them.This problem seriously affects the stability of the rolling process and product quality,and restricts the rapid marketization of the frontier technology.Therefore,it is of great engineering significance to study the law of axial deviation,reveal the mechanism of axial deviation and put forward reasonable solutions from the aspect of process control based on the current equipment.In this paper,according to the equipment and process parameters of the large cylindrical shell rolling in a heavy machinery plant,firstly,the thermophysical property parameters and stress-strain curves of the material for simulation 16 Mn were obtained by using the material performance simulation software JMat Pro.On this foundation,the three dimensional thermo-mechanical coupling model of radial large cylindrical shell rolling was established on MSC.Marc platform by using the local follow-up coordinate system to simulate the hydraulic adjustment mechanism of the holding roller on both sides,which is an innovative method.Based on the simulation results,the hot rolling forming process of the ideal cylindrical shell,inner and outer conical cylindrical shell was analyzed.The mathematical relationship model was established.The essence of axial deviation during the rolling process of conical cylindrical shell was revealed from the two aspects of the relationship between the different radius of two ends and the axis angle and the relationship between the axis angle and the axial deviation.Then the influence law of relevant size and process parameters on the axis angles and axial deviations was investigated,and the theoretical analysis by using the deviation mechanism was carried out to verified the correctness of the theoretical model as well.From qualitative and quantitative two aspects to explore the axial deviation tilting roll control method.The results show that under the double roller driving and progressive feed mode of the drive roller,the tilting angle of the driving roll for the inner cone condition is slightly less than its taper,but the tilting angle for outer cone condition is slightly greater than its taper.The reasonable tilting angle of the driving roller can effectively control the axial deviation problem of the cylindrical shell,and it also has the effect of correcting the product shape after rolling.In the end,a measurement scheme for measuring the size and shape of the cylinder was briefly introduced.