High Speed Steel Roll Finite Element Analysis Of Fracture

At present, the requirement of the shape and the thickness of hot-rolled on the plate is increasingly stringent. part of rolling parameters can be obtained by the field experiment , but because of the complexity of hot-rolled process, most potential parameters which are closely associated with the rolling process can not be obtained. For this reason, to get a desirable rolling parameters have to rely on the calculation of numerical simulation. Consumption of roller is the most consumption of rolling industry. Therefore, through the numerical simulation of the process of hot rolling will provide a basis and reference with the study of failure and life of roller.By virtue of internationally accepted best one of the finite element analysis software ANSYS, First, established finite element model of work roll - rolled piece of hot rolled plate. Achieved dynamic simulation of the hot rolled. Got the curve of equivalent stress, temperature, thermal stress after work roll was working a lap. There are three regions of larger equivalent stress. The contact regions with the rolling, contact regions with the backup roll , junction of core and exterior, in contact regions with the backup roll ,the greatest changes of effective stress , the maximum is 450MPa , here is more prone to produce plastic zone,junction of core and exterior, due to more constraints , Therefore, the change effective stress is least, the change of temperature is large, the maximum is 480℃,finally stabilized at 90.25℃. The trend of axial and circumferential thermal stress was same,the maximum is 1000MPa,radial stress is small, the trend was opposite , Second, based the work roll - rolling finite element model which was no crack , laid surface cracks on it , obtained the stress intensity factor and J integral at different times after work roll was working a lap. And analyzed the variation of the stress intensity factor and J integral,The most value of stress intensity factor and J integral appear at the same time, contact with the backup roll and rolled piece . Crack inclination angle has little effect on both, crack length and load is the main factors. Then, Done the calculation of fatigue life, compared theoretical calculation with ANSYS fatigue calculations , the work rolls with crack can approximately worked 5 600 times, work roll with no crack can approximately worked 200 000 times, obviously,cracks has a great influence the life of work rolls. Final, to conduct the critical condition of crack propagation, crack propagation of the critical condition of High speed steel rolls was, critical temperature is about 410℃, critical load is about 420MPa, crack angle is about 90°.Conclusion is very close to the classic criteria for mixed-mode crack .The present studying provided a theoretical basis and reference for enhancing the life of high speed steel rolls and preventing the crack propagation, the conclusions and data above had certain guiding sense and reference value to the actual production.