Development of Lines for Continuous Heat T reatment of Aluminium Alloy Strips
The main tendencies in the development of lines for continuous heat treatment of aluminium alloy strips are analyzed. Heating furnaces were perfected due to application of high-performance fans and an increase in the number of temperature control zones. Uniformity of temperature distribution, suspended strip transportation system, and control accuracy of strip tension in the furnace were improved as well. Different cooling methods, starting from the water jet cooling and up to the air cooling, are used in the quenching units allowing a wide-range control of the strip cooling rate. A new method of water fog cooling is described. Also the lines were newly equipped with a strip quality inspection device. The changes in the automatic control system of the continuous heat treatment lines were most significant. Manual operations were minimized. Visualization of the whole process, which is integrated into the human-machine interface, is used. Mathematical models are used for calculations of heat treatment conditions.