Vibration Analysis Of CSP Hot Strip Mill

Thin slab continuous casting and rolling production line of Handan iron and steel group was introduced from Germany SMS during the Ninth Five-Year Plan period.The line was the world’s iron and steel industry in the1990s high-tech CSP(Compact Strip Production) production line. There are six finishing mills in the line. Since the line released in2003, F3finishing mill often occur torsional vibration in the main drive system and vertical vibration in the rolling mill housing, which seriously impact on the quality and yield of the products.F3finishing mill was taken as the research object in this paper. The mechanics model and mathematical model of main transmission system and rolling mill system was established. The natural frequencies of the two systems and the main vibration modes of the mill housing were calculated by using MATLAB software. According to the data of vibration frequency of the field test, that the abnorbal frequency of the rolling mill is similar to the frequency of the third step natural frequency of the main drive system; the dominant frequencies are concentrated in connecting shafts with curve-tooth coupling and joining coupling of the main transmission system. It is certain that the vibration source of the mill in the main transmission system.The simulation and analysis of main drive system based on the software MATLAB/Simulink show that the torsional vibration of main drive system is mainly caused by mechanical clearance. The solution to the torsional vibration was putted forward. The dynamic characteristics analysis of F3mill housing by using the software ANSYS show that the maximal vibration peak in the rolling mill occurs at the40Hz of exciting frequency. This shows that the vertical torsion will occur when the rolling mill is subject to the excitation force near corresponding frequency. The solution to the vertical vibration was putted forward.It is found that the bending vibration and vertical vibration signal contain torsional vibration frequency through the study of the coupling phenomena of the bending-torsion-coupled viberation and torsion-vertical vibration in the mill. These results show that the bending vibration and vertical vibration of the mill are caused by the torsional vibration in main drive system, verifying the correctness of theoretical analysis. The study on nonlinear vibration signal in this paper to confirm the vibration model of mill is steady self-excitation vibration. The analysis results of electro-mechanical coupling vibration in the mill show the torsional vibration of drive system is attributed to that harmonic torque near corresponding frequency which is generated by the electromagnetic harmonic component in SCR rectifier system.