The Analysis And Research On The Tension In Seven Roller Pre-Straightener

As a finishing technology, straightening is the key process for quality assurance in heavy plate production. In recent years, as the development of national defense, chemical and oil industry, higher quality heavy plate is used widely, traditional straightening technology cannot meet the needs of market. At the same time, the pre-straightening technology caused more attention. Pre-straightening machine is decorated in the cooling equipment and the finishing mill, in order to improve the heavy plate flatness and eliminate the residual stress. Through the process of the pre-straightening technology, the heavy plate can satisfy the market requirements.A lot of research on theoretical design method and calculation model has been done, but only a little research about the tension on the effects of parameters. The tension will affect the straightening effect and power output.Our study is based on the metallurgical laboratory “The mechanism research of the marks on the surface of pre-straightening roller about generous plate seven roller pre-straightening machine in Bao Steel”. Through the analysis of deformation characteristics of wide and heavy plate in the pre-straightening process, and the analysis of neutral layer velocity of each deformation unit, we have studied the influence of tension on driving torque,pre-straightening force, plate shape. A mathematical model of the influence of the tension force on the pre-straightening process has been established. The main research conclusions are as follows:(1) Through the combination of field measurement and theoretical study, we have verified the existence of the tension between the roller in the actual straightening process;(2) By comparing field measured data with finite element calculation data, we have determined the reliability of the model, and have analyzed the influence of the tension between rolls on the direct torque and straightening stress. It has been found that the tension makes straightening force increase and cause straightening torque to decrease;(3) We have optimized the straightening process parameters, and have analyzed the results before and after optimization. After optimization of process parameters, the negative torque phenomenon in No.6 roller has been alleviated, and the abrupt increase of the torque in No.3 and 5 rollers can be eliminated. In addition, strip shape flatness is improved and residualstress distribution is more uniform than before.After analyzing the influence of tension on the straightening parameters, this study will have a certain guiding significance on ascertaining the straightening process.