Experimental study of rolling accuracy on stand 800

Abstract

The study of fluctuations in the dimensions of rolled products was carried out for rolled profiles, which are a finished product, because fluctuations in the dimensions of the cross sec-tion and the length of the roll lead to the appearance of rods of excessive length when cutting on hot saws. Cutting the rolls does not always allow obtaining a mass of the blank, from which only rods of a measured length will be obtained in the next division. Therefore, in-creasing the accuracy of mass of square or round blanks allows to reduce fluctuations in the roll length and the appearance of rods of off-gage length and prevent the appearance of short blanks. The purpose of the work is an experimental study of the process of rolling on the state of 800 square profiles to determine the influence of rolling parameters on the dimensions of the cross-section and the length of the roll. During the study, fluctuations in ingot mass, rolling dimensions, and rolling length were determined, regression equations and correlation coeffi-cients were obtained for the dependence of rolling dimensions and length on ingot mass, changes in interroll gap and time delay before the finishing stand. It was established that the mass of the ingot fluctuates within significant limits - 638 kg, which is caused by fluctuations in the mass of the melt. Fluctuations in the mass of the ingot within one molding bed are caused by the dimensions of the ingot molds, the pouring height and is within 154 kg. Fluc-tuations in the dimensions of the roll are carried out within the following limits: thickness - 1.0 mm, width - 0.5 mm, length - 5.3 m. Changing the inter-roll gap can be used to correct the length of the finished roll in a small range of lengths, if the mass fluctuations occur within accuracy of filling on one molding bed. It is necessary to take additional measures to stabilize the weight of the ingot. The influence of delays in the state line, which occur during rolling and lead to instability of the rolling temperature regime, for this type of profiles does not sig-nificantly affect the dimensions of the cross section and the length of the roll.