МЕТОД ИССЛЕДОВАНИЯ НАГРЕВА ОКИСЛЯЮЩЕГОСЯ МЕТАЛЛА В ПРОГРАММНЫХ ПАКЕТАХ ИНЖЕНЕРНОГО АНАЛИЗА

Abstract

The article is devoted to the development of a method for modeling the heating of oxidized metal billets, in which the dimensions and thickness of the scale layer vary with time. The approach used in this development facilitates the appliance of modern software packages for the analysis of objects with varying geometry; and due to this the complexity of developing mathematical models of several metallurgical processes can be dramatically reduced. To simulate the process of metal oxidation, the method of equivalent thermal conductivity was used. The experimental verification of the method is performed and the possibility of its use for improving the methods of controlling the processes of industrial heating is shown. This method was worked out during experiments on the furnace №3 with walking beam of the mill 150 at Nizhne-Serginsk Hardware and Metallurgical Plant. Calculations were made to determine the thickness of the scale layer, which varies with time; the corresponding dependencies were constructed. The problem was solved by ANSYS Multiphysics software package as a problem of non-stationary heat conduction with boundary conditions of the first kind. During modeling, a finite-element grid was constructed, sufficiently detailed to obtain reliable results and, at the same time, allowing to solve the problem on low-power computers. In the course of solution, a number of simplifications were applied, in particular, simplification of the computational algorithm, in which the thickness of the scale layer is uniquely determined by surface temperature of the billet. Temperature distribution along the billet’s thickness was determined. Graphs and isotherms were constructed to compare values of the temperatures in metal and in scale layer. Also, a comparison of the temperature differences in the scale layer determined by the calculation method was made for the furnace and experimental conditions. In this study, the problem is considered as nonstationary, with varying boundaries. The research object is preparation of the metal (real solid) with scale layer, increasing with time. When solving a problem, this real solid was replaced by a conditional one with constant averaged dimensions. According to the equality of thermophysical processes, properties of the conditional solid were determined, whose change is equivalent to the dimensions of the real solid. © 2019, National University of Science and Technology MISIS. All rights reserved.