TO THE DEVELOPMENT OF STATISTICAL MODELS OF WEAR ROLLS OF LONG PRODACTS MILLS

Abstract

For long products rolling mills, a change in the indicators of wear and costs in a relatively wide range is characteristic, depending on the type of rolled product, the features of the technology, the materials used in the rolls, and other factors. This largely determines the level of operating costs when rolling profiles. Therefore, increasing the wear resistance of long product mill rolls was and remains an urgent task in metallurgy.
 The purpose of the work is to analyze the structure of known mathematical models of wear of rolls of rolling mills, features of wear of rolls of individual long-products rolling mills, and to determine a general approach to the construction of statistical models for predicting the wear of such rolls.
 From the review of the literature, it was established that the structure of most wear models includes technological parameters, that are most significant for a certain state, and an empirical coefficient. For the conditions of long products mill, in each of the stands, most of the parameters change within rather narrow limits due to technological deviations. Therefore, for stands mills in such conditions, it is advisable to use "local" statistical models obtained from the results of wear measurements. The structure of such models can be represented as the product of the empirical coefficient, which indirectly reflects the influence of the main technological parameters, and the friction way, as the main factor of the Archard model.
 As an empirical coefficient, it is recommended to use the indicative wear intensity of the rolls, defined as the ratio of the amount of wear of the groove roll to the mass of rolled products obtained from this pass. The revealed features of the change in the wear intensity indicator are due to the processes of processing the initial surface and the formation of a certain microstructure. After the rolling of the threshold mass of rolled products, these processes are completed and the indicator of wear intensity reaches a stable value. The initial and permanent value of the wear intensity indicator, as well as the threshold value of the mass of rolled steel, are determined based on empirical data on wear and mass of rolled steel for each of the stands mill.
 The proposed method of determining wear using the wear intensity indicator as an empirical coefficient that indirectly reflects the influence of all significant factors of the process provides sufficient accuracy of wear prediction and can be used to determine the costs of rolls.