Using Mathematical Methods for Analysis of Temperature–Time Conditions of Arc Surfacing Upon Manufacturing of Steel-Aluminum Compositions

Abstract

A mathematical model for analysis of temperature–time conditions of arc surfacing upon fabrication of steel-aluminum compositions has been developed and verified. In the course of simulation, the database of SVARKA software has been supplemented with thermophysical properties (thermal conductivity and thermal capacity at constant pressure and volume) of the considered materials as a function of heating temperature. The geometric model of the object during simulation of arc surfacing has been preset as a single body, which can consist of various materials, for instance, in the case of formation of functional coatings based on nonferrous metals on steel substates. The parameters of the heat loads of the heating source are as follows: motion speed of motion, power, distribution along and across seam, as well as existence and grade of surfacing material. The heat propagation for argon arc surfacing using a non-consumable electrode has been calculated according to the design with a normal circular source located on the surface of a flat layer and exposed to limiting action of the sheet bottom plane. The selected calculation design reflects all the main features of argon arc surfacing, including the welding arc heat input to a massive body from its surface, low pressure of welding arc, and insignificant penetration of active spot into liquid metal. It has been demonstrated that, owing to accounting for thermophysical properties of the Fe–Al intermetallic layer located in diffusion zone, the mathematical model with uncertainty not exceeding 8% makes it possible to determine the heating temperature not only at steel–aluminum interface but also at any point of the specimens both upon joining of transitional bimetallic steel-aluminum elements with aluminum or steel structures and upon formation of functional aluminum coatings by surfacing, including composite materials.