Research On Stable Travelling Technology Of Strip In Continuous Annealing Production Line

A continuous annealing production line (CAPL) is the developing tendency of strip annealing technology, which composed of many processing procedures, including strip cleaning, annealing, leveling, surface check, anointing, re-coiling and cutting. The strips produced by CAPL can attain annealing without felting defaults, and finally get a good surface. But the most serious problem that exists in CAPL is strip buckling phenomenon that often occurred in hearth, which could cause the break of the strip and make the stable strip traveling with a high speed impossible. That severely influences the output, quality and efficiency of CAPL. With the fast development of automobile, light industry, home appliance and construction industry during the eleventh"five-year-plan", the demand of cold rolling and hot zincification strips is increasing. So as core technology of CAPL, it is necessary to make a basic, then deeper research on fast stable strip traveling technology.In production, many effects can lead to the bad strip profile, like the tension applied on strip, the bad profile of original strip, the work roll profile and the uniformity of heating and cooling. All these effects stop the production line from stable function. This paper will make a research on traveling technology by studying the major factor—buckling and misguiding phenomena. To get more practical data, a set of equipment for experiment is built on the basis of Japan's research. For buckling and misguiding usually occurred in high temperature strip, aluminum foil at normal temperature with similar behaviors to strip at high temperature is used to do the experiments. The results showed the effects of different roll crown, flat length, roughness, profile, aluminum foil size et al on critical buckling stress and the offset ability of rolls. In addition, finite element method software ABAQUS is employed to simulate the dynamic process of buckling and the mechanism of transverse compressive stress. The simulations showed the relationships between strip tension, roll crown, flat length, roughness and transverse compressive stress, which can have a prediction of buckling.Those research conclusions provide believable rule for roll design and choosing, the application of which can effectively prevent the appearance of buckling and misguiding, and enhance the production efficiency.