In order to continuously simulate multi-pass plate rolling process,a 3-D elastic hollow-roll model was proposed and an auto mesh-refining module with data passing was developed and integrated with FE software,Marc.The...In order to continuously simulate multi-pass plate rolling process,a 3-D elastic hollow-roll model was proposed and an auto mesh-refining module with data passing was developed and integrated with FE software,Marc.The hollow-roll model has equivalent stiffness of bending resistance and deformation to the real solid and much less meshes,so the computational time is greatly reduced.Based on these,the factors influencing plate profile,such as the roll-bending force,initial crown,thermal crown and heat transfer during rolling and inter-pass cooling can be taken into account in the simulation.The auto mesh-refining module with data passing can automatically refine and re-number elements and transfer the nodal and elemental results to the new meshes.Furthermore,the 3-D modeling routine is parametrically developed and can be run independently of Marc pre-processing program.A seven-pass industrial hot rolling process was continuously simulated to validate the accuracy of model.By comparison of the calculated results with the industrial measured data,the rolling force,temperature and plate profile are in good accordance with the measured ones.展开更多
This work gives a comparison on the microstructural characteristics,textural discrepancies,and twinning behaviors of lamellar and equiaxed nearβ-Ti alloys during multi-pass cross rolling with a rolling reduction of 2...This work gives a comparison on the microstructural characteristics,textural discrepancies,and twinning behaviors of lamellar and equiaxed nearβ-Ti alloys during multi-pass cross rolling with a rolling reduction of 20%,50%and 80%.The results showed that the restoration mechanism of the alloy inβphase is strongly dependent on theαmorphologies,and in comparison,strain path has weaker influences on the grain refinement of theβmatrix.Therefore,the texture intensities of bothαandβphases were weakened owing to the dynamic recrystallization(DRX)of the two phases in the equiaxed microstructure.While,with regard to the lamellar microstructure,dynamic recovery(DRV)of theβphase predominated,forming elongatedβsubgrains.Besides,theαandβmatrix in lamellar microstructures obeyed the Burgers orientation relationship,which was gradually broken down until the final reduction.Lastly,the{1101}twinning exhibits a strong size effect.With the continuous DRX ofαphases,theα-twinning is suppressed owing to progressive grain refinement.The activation ofβ-twinning,namely{332}?113?and{112}?111?,in nearβ-Ti alloys is heavily dependent on the deficientβ-stabilizing elements and the local stress concentration.These findings provide an effective way to obtain ultra-fine grain microstructures of this alloy.展开更多
Multi-pass slab vertical-horizontal （V-H） rolling process with variable edging roll shape have been simulated with explicit dynamic finite element method and updating geometric method. The distributions of plastic s...Multi-pass slab vertical-horizontal （V-H） rolling process with variable edging roll shape have been simulated with explicit dynamic finite element method and updating geometric method. The distributions of plastic strain contour in slab daring rolling process with different edging roll and under different rolling stage have been obtained. The results show that there exist two thin strain assembling zones in slab when the flat edging roll is used, and there just exist one strain assembling zone in slab when the edging roll with groove is used. And compared the deformation equality between flat edging roll and edging roll with groove, the lateris better than the former, which supplies the theory prove to the slab deformation distribution during V-H rolling process and is helpful for predicting the slab texture.展开更多
In this study,the substructure formation in a multi-pass rolled aluminium single crystal{001}<110>was investigated by the crystal plasticity finite element model,and the predations were validated by experimental...In this study,the substructure formation in a multi-pass rolled aluminium single crystal{001}<110>was investigated by the crystal plasticity finite element model,and the predations were validated by experimental observations at both macro-and micro-scale.A finite element model for multi-pass rolling was developed to follow the real experimental rolling scheme,by which the through-thickness macroscopic subdivision was successfully predicted up to a 90%reduction.The macro-subdivision was featured by forming matrix bands through the thickness,and the deformation behaviours,in terms of slip activity,shear strain and crystal rotation,alternated between matrix bands.The development of matrix bands,stability of crystal orientations,and correlation between slip activity,shear strain and crystal rotation have been investigated.Another modelling method,Submodel,was used to exceedingly increase the mesh resolution in smaller regions of interest,and the experimentally observed microstructure,i.e.,micro-subdivision was explicitly and spatially revealed.Similar predictions were obtained in Submodels with different element sizes,which proves the feasibility of this method in predicting microstructure formation.It was found that the substructure formation by varying slip activity and crystal rotation between domains is energy favourable.The procedure of substructure formation was explained based on the predictions,three types of substructure have been identified,and the substructure formation was discussed.展开更多
基金Project(20050248007) supported by the Specialized Research Fund for the Doctoral Program of Higher Education of China
文摘In order to continuously simulate multi-pass plate rolling process,a 3-D elastic hollow-roll model was proposed and an auto mesh-refining module with data passing was developed and integrated with FE software,Marc.The hollow-roll model has equivalent stiffness of bending resistance and deformation to the real solid and much less meshes,so the computational time is greatly reduced.Based on these,the factors influencing plate profile,such as the roll-bending force,initial crown,thermal crown and heat transfer during rolling and inter-pass cooling can be taken into account in the simulation.The auto mesh-refining module with data passing can automatically refine and re-number elements and transfer the nodal and elemental results to the new meshes.Furthermore,the 3-D modeling routine is parametrically developed and can be run independently of Marc pre-processing program.A seven-pass industrial hot rolling process was continuously simulated to validate the accuracy of model.By comparison of the calculated results with the industrial measured data,the rolling force,temperature and plate profile are in good accordance with the measured ones.
基金National Natural Science Foundation of China(51801149)Sponsored by Ministry of Industry and Information Technology of the People’s Republic of China(TC170A2KN-8)。
基金financial supports from the National Natural Science Foundation of China(No.51871242)Scientific and technological innovation projects of Hunan Province,China(No.2017GK2292)the National Key R&D Program of China(2018YFB0704100)。
文摘This work gives a comparison on the microstructural characteristics,textural discrepancies,and twinning behaviors of lamellar and equiaxed nearβ-Ti alloys during multi-pass cross rolling with a rolling reduction of 20%,50%and 80%.The results showed that the restoration mechanism of the alloy inβphase is strongly dependent on theαmorphologies,and in comparison,strain path has weaker influences on the grain refinement of theβmatrix.Therefore,the texture intensities of bothαandβphases were weakened owing to the dynamic recrystallization(DRX)of the two phases in the equiaxed microstructure.While,with regard to the lamellar microstructure,dynamic recovery(DRV)of theβphase predominated,forming elongatedβsubgrains.Besides,theαandβmatrix in lamellar microstructures obeyed the Burgers orientation relationship,which was gradually broken down until the final reduction.Lastly,the{1101}twinning exhibits a strong size effect.With the continuous DRX ofαphases,theα-twinning is suppressed owing to progressive grain refinement.The activation ofβ-twinning,namely{332}?113?and{112}?111?,in nearβ-Ti alloys is heavily dependent on the deficientβ-stabilizing elements and the local stress concentration.These findings provide an effective way to obtain ultra-fine grain microstructures of this alloy.
文摘Multi-pass slab vertical-horizontal （V-H） rolling process with variable edging roll shape have been simulated with explicit dynamic finite element method and updating geometric method. The distributions of plastic strain contour in slab daring rolling process with different edging roll and under different rolling stage have been obtained. The results show that there exist two thin strain assembling zones in slab when the flat edging roll is used, and there just exist one strain assembling zone in slab when the edging roll with groove is used. And compared the deformation equality between flat edging roll and edging roll with groove, the lateris better than the former, which supplies the theory prove to the slab deformation distribution during V-H rolling process and is helpful for predicting the slab texture.
基金Australian Research Council Discovery Project(DP170103092)。
文摘In this study,the substructure formation in a multi-pass rolled aluminium single crystal{001}<110>was investigated by the crystal plasticity finite element model,and the predations were validated by experimental observations at both macro-and micro-scale.A finite element model for multi-pass rolling was developed to follow the real experimental rolling scheme,by which the through-thickness macroscopic subdivision was successfully predicted up to a 90%reduction.The macro-subdivision was featured by forming matrix bands through the thickness,and the deformation behaviours,in terms of slip activity,shear strain and crystal rotation,alternated between matrix bands.The development of matrix bands,stability of crystal orientations,and correlation between slip activity,shear strain and crystal rotation have been investigated.Another modelling method,Submodel,was used to exceedingly increase the mesh resolution in smaller regions of interest,and the experimentally observed microstructure,i.e.,micro-subdivision was explicitly and spatially revealed.Similar predictions were obtained in Submodels with different element sizes,which proves the feasibility of this method in predicting microstructure formation.It was found that the substructure formation by varying slip activity and crystal rotation between domains is energy favourable.The procedure of substructure formation was explained based on the predictions,three types of substructure have been identified,and the substructure formation was discussed.
