Development of Principles of Technological Process Control of High Quality Metals and Alloys Melting by Method of Chamber Electroslag Remelting(ChESR)

Abstract

Vacuum-arc remelting, vacuum-induction, electronbeam and plasma-arc cold hearth melting are the main technological processes for producing of titanium and its alloys ingots. But in some cases these processes can not to provide the necessary quality of metal. As was shown in the series of the research works, fulfilled in Donetsk National Technical University (DonNTU), the electroslag remelting of metals and alloys under slag systems with active additions in the chamber type furnaces (ChESR) permits to solve the problems, for which application of traditional methods of electrometallurgy causes the difficulties. Producing of high-quality ingots of titanium, its alloys and intermetallides may be considered as problem of this type. But providing of optimal calcium concentration in the slag close to equilibrium during the process is one of the main problems of ChESR. Using of information measuring system is the effective way of the solving of this task. One of parameters, which permit to establish the correspondence between changes of flux composition and current and voltage of process, is the harmonic spectrum of remelting current and voltage. This unique approach may be used for control and support of stable slag composition during all melting period. Analyzing and comparing of processes, which take place in technological unit, with changes in harmonic composition of signal, some dependencies can be derived. Changes of current and voltage in dependence on metallic calcium concentration in slag is one of them.