The development of calculation method for reducing of wall thickness along the cone of deformation at the cold rolling mills

The development of calculation method for reducing of wall thickness along the cone of deformation at the cold rolling mills. The process of cold pilger rolling is widely used for manufacturing cold and hot deformed precision pipes of a wide range of alloys and steel grades. Cold and hot rolling as well as rolling without emulsion are used in the cold pilger rolling , process. It is very dynamic nowadays and modern mill permit lip to more than 280 double movements per minute. In spite of relatively small feed (2 - 4 mm) and considering the deformation cone length (300 - 500 mm), metal is shaped in rather tough conditions. The article deals with the analysis and the development of the existing calculation method for reducing wall thickness along the cone of deformation at the CRM. The developed method can be used both in the process of standard feed and the feed with rotary movement before the forward stroke as well as before the backward stroke. The value of swaging is crucial for calculations of swaging in an instantaneous deformation site, which, by-turn, defines the calculation accuracy of energy-power parameters of the process. The offered method allows to consider both the amount of metal which hasn't been deformed due to elastic deformation of a stand and the amount of metal which hasn't been deformed after the working stroke of the stand because there are groove outlets. That makes possible to increase the delivery accuracy of swaging of the wall thickness between the forward and backward strokes at the testing cone sections. Thus there is a possibility to improve the calculation accuracy. The calculations results have been checked in practice process of cold pilger rolling and prove the method efficiency.