Numerical Simulation Of Multi-step Rolling Of Large-scale Special Ring

Large-scale ring parts are the key components of offshore wind power generation,aerospace,marine shipbuilding and the extensive application of electric power,petroleum and construction machinery.The new technology of Ring rolling has been able to roll out the production of rectangular section ring,it has a labor-saving,energy saving,materials,high production efficiency,low production costs and other significant features.In the actual contour ring rolling process,the rolling process is unstable,the size of the rolling ring is low and the microstructure and mechanical properties are difficult to control,rolling force is large,mold are easy to damage,which to a certain extent,limit the contour ring rolling process in the application of the project.To solve the above problems must study and master the rolling process of metal flow law,select a reasonable rolling die and a reasonable core roller feed strategy and roll motion control method.In this paper,we used the numerical simulation method,the thermo-mechanical coupling simulation analysis of a large non-rectangular section with outer groove and inner step were carried out.The flow stress model of Q345 E steel was established by Gleeble-3500 test machine,in view of the complex contour characteristics of forming products,used multi-step rolling,for each step rolling to be improved several times with rolling rough,designed two sets of reasonable mold,the motion control equations of the roll in the rolling process were deduced,the plastic forging conditions and bite conditions of the ring pieces during the rolling process were determined,and the reasonable range of the roll speed and the feed rate of the core roller were obtained.On the basis of the establishment,the finite element model of the inner step double piece rolling finite element model and the hot rolling process of the outer groove ring with inner step were established respectively,The equivalent strain and temperature of the two kinds of ring rolling parts are obtained respectively with the change rule of the rolling time,The influence of different process parameters such as heating temperature,driving roller speed and core roll feed rate on the equivalent strain and temperature distribution,radial rolling force and moment of ring rolling process are studied systematically,the second step outside the groove rolling process parameters were Optimized,a finite element model that can be applied to the actual production is determined.Numerical simulation studies shows that,the use of the established model can achieve the production of multi-step rolling.The maximum response of the ring in the outer diameter of the corners of the upper and lower diameter of the two ends When the preheat temperature is1250?,core roller speed is 0.8mm / s,1mm / s,drive roller speed is 30.6r / min in rolling ring,the plastic deformation zone of the ring extends from these parts to other parts of the ring,the outline of the steps is fully filled at 100 s,full of the situation is better,the local deformation of the ring is within 100 s,diameter growth is not obvious,the diameter of the main growth occurred in 100 s after the rolling stage;The feed rate of the core roller is 1.2mm / s,0.8mm / s and 0.3mm / s,respectively,when the outer groove is removed,the speed of the drive roller is 7.644 r / min,the outer groove of the ring is filled in about 85 s,the plastic deformation of the whole ring is the outer groove part and the radius of the ring radius of the step to the other parts of the ring part of the expansion,the maximum value of the equivalent strain is at the outer groove and the step.