Dissertation
Dissertation > Industrial Technology > Metallurgy and Metal Craft > Metal pressure processing > Rolling > Rolling mill machinery equipment > Bodies and equipment of the mill primary columns > Roller and roller bearings

Research on Thermal Deformation Behavior of Work Roll in Finishing Trains of Hot Strip Mill

Author GaoJianHong
Tutor HuangChuanQing;WangMin
School Shanghai Jiaotong University
Course Materials Processing Engineering
Keywords Hot-rolled Temperature field Thermal crown Finite Element Plate -shaped
CLC TG333.17
Type Master's thesis
Year 2009
Downloads 232
Quotes 2
Download Dissertation

With cars, light industry, household appliances and electrical manufacturing industry for the continuous improvement of the quality requirements of the plate-shaped, plate-shaped a quality issue has become critical in the production of Hot Strip Mill. Good or bad the quality of the strip shape rolling process set out roller seam, so the load by controlling the roll gap can strip to achieve good geometric accuracy. Control load roller seam not only need to know the degree of opening of the nip point, but also need to know the distribution of the roll gap along the width direction of the plate, which relate to many aspects of the roll after the deformation of the force of the lower roll in the rolling force. The work roll thermal deformation, wear of the work roll and the work roll bending deformation is determined there are three main factors carrier roll gap, wherein the influence of the thermal deformation of the roll gap is very significant. Hot rolling process, the roll of thermal expansion of the central can not only bring the heat crown exceeds 300μm, and roll the thermal deformation of the changing in the entire production process, resulting in the production process is unstable. Combined with the complexity of the boundary conditions, is difficult to establish to adapt to the various conditions of a generic model, so thermal deformation of the work rolls is difficult to achieve a satisfactory accuracy, accurate prediction of the thermal deformation of the roll has become the hot-rolled plate-shaped control technology difficulty. Study to establish the model of thermal deformation in line with the actual situation, not only of theoretical significance, but also has practical value. In this paper, Baosteel 1880mm hot strip production practice, according to the theory of heat transfer roll heat transfer on the basis of a comprehensive analysis to determine the roll heat transfer coefficient, air convective heat transfer coefficient, the cooling water of the convective heat transfer coefficient and input roll heat formula. Starting from the energy conservation law and the heat conduction equation, the use of general-purpose finite element software ANSYS calculation model, including the establishment of the two rolls of two-dimensional non-steady-state temperature field model and axisymmetric temperature field in the cross-section of the roll center plane temperature field model, and to a roll thermal crown simulation flow chart. Difficult to determine the boundary conditions for the hot rolling process is complex, difficult problem, in-depth Baosteel 1880mm hot rolling production site measurement and test mainly the work roll surface temperature and thermal contour tracking measurements. Then using a calculation model based on the collection of process parameters simulation analysis to compare with the scene of the measured roll mild roller-shaped data, optimization of the relevant parameters of the model boundary conditions, the calculation model to meet the actual use of the site requirements . Calculation model of the rolling process in the temperature field and thermal deformation process simulation, the roll surface of the rolling process and the internal temperature field changes, as well as a unit rolling plan roll total thermal crown degrees and some thermal camber variation. And to analyze the relationship between the parameters and thermal deformation of roll steel, strip width, rolling rhythm, the speed of roll cooling system and its impact on the strip shape, draw valuable conclusions for further improvement of the plate-shaped control mathematical model, to improve the accuracy of the plate-shaped to provide a theoretical basis.

Related Dissertations
More Dissertations