For the drum of hot rolling coiler is prone to be easily destroyed, the type of MMU-5G abrasion tester was applied to revealing the friction and wear behavior. The morphology observation by scanning electron microscope (SEM) demonstrates the wear mechanism of the drum, and the test data of the influence coefficient of the normal pressure, relative sliding speed and surface lubrication conditions acted on the linear rate of the wear could be obtained by the regression method. A calculation model, which considers the factors of the structure of the drum, coiling tension and coiling strip specifications, was established by the combination method to predict the wear life of the drum. Then the practical production data was applied into this model and the analysis result was in good accordance with that of actual production.
A high-precision shape detecting system of cold rolling strip is developed to meet industrial application,which mainly consists of the shape detecting roller,the collecting ring,the digital signal processing(DSP) shape signal processing board and the shape control model.Based on the shape detecting principle,the shape detecting roller is designed with a new integral structure for improving the precision of shape detecting and avoiding scratching strip surface.Based on the DSP technology,the DSP shape signal processing circuit board is designed and embedded in the shape detecting system for the reliability and stability of shape signal processing.The shape detecting system was successfully used in Angang 1 250 mm HC 6-high reversible cold rolling mill.The precision of shape detecting is 0.2 I and the shape deviation is controlled within 6 I after the close loop shape control is input.
Because the work environment of segment is complex, and the wear failures usually happen, the wear mechanism corresponding to the load is a key factor for the solution of this problem. At present, many researchers have investigated the failure of segment, but have not taken into account the compositive influences of matching and coiling process. To investigate the wear failure of the drum segment of the hot rolling coiler, the MMU-5G abrasion tester is applied to simulate the wear behavior under different temperatures, different loads and different stages, and the friction coefficients and wear rates are acquired. Scanning electron microscopy(SEM) is used to observe the micro-morphology of worn surface, X-ray energy dispersive spectroscopy(EDS) is used to analyze the chemical composition of worn surface, finally the wear mechanism of segment in working process is judged and the influence regulars of the environmental factors on the material wear behaviors are found. The test and analysis results show that under certain load, the wear of the segment changes into oxidation wear from abrasive wear step by step with the temperature increases, and the wear degree reduces; under certain temperature, the main wear mechanism of segment changes into spalling wear from abrasive wear with the load increases, and the wear degree slightly increases. The proposed research provides a theoretical foundation and a practical reference for optimizing the wear behavior and extending the working life of segment.
