Finite Element Analyse Of Quenching Process Of High Chromium Forged Backup Roll

Because of various influence factors and complicated boundary conditions, the quenching process of high chromium forged backup rolls have been the key and difficult points of heat treatment numerical simulation domain. Therefore, the research has important theoretical and practical significance.In view of the above questions, taking Cr5 forged backup rolls as investigated subject, this paper put emphasis on the relation of temperature , microstructure and stress field of final heat treatment especially the quenching process of backup rolls.First, a finite element simulation model which can calculate the coupled temperature-microstructure-stress field is set up. On the base of analyzing the characteristics of spray quenching process of backup rolls, the simulation steps and the corresponding boundary conditions are determined and the parameters of calculating the coupled temperature-microstructure-stress field are given.Then, the spray quenching process of Cr5 forged backup rolls is simulated using the Finite element software DEFORM. The influence of with insulation measures or not during transfer of backup rolls from differential temperature furnace to spray quenching equipment is taken into account. The distribution rules of temperature , microstructure and stress field can be obtained after quenching. The history curves of temperature and stress of special nodes on the backup rolls, the microstructure and residual stress distribution on middle section after quenching are analysed in detail. Through comparative analysis, it's more reasonable without insulation measures during transfer process.Finally, the influence of martensitic transformation for quenching instantaneous stress is analysed through the finite element simulation results. The results show that peak of instantaneous tensile stress easily appears in near surface. Besides, the improvement programs for subsistent problems are given. On the another hand, the influence of quenching time for continuous spray on the result is also considered. After comparative analysis, it's more reasonable to reduce the continuous quenching time to 40 min in the existing technology and equipment conditions.