Research On Arc Stability Stirring Control System For Vacuum Arc Remelting Furnace

Vacuum arc remelting furnace is an important equipment that smelting rare metal such as titanium and its alloys. The arc stability stirring control system improves quality of ingot and the control of parameters has a direct effect on the quality of ingot. Therefore, it has a great significance to research on arc stability stirring control system for vacuum arc remelting furnace.According to the characteristics and composition of arc stability stirring control system for vacuum arc remelting furnace, this paper analyzed the technological characteristics of arc stability stirring system in arc starting, melting and feeding, the three different melting stages, and put forward system control requirements. Through analyzing association between ingot and arc stability stirring current, we established a SQL SEVER database which can make arc stability stirring current matching and setting automatically. On this basis, because of permeability of titanium element in smelting process, we analyzed longitudinal magnetic field and temperature field in furnace and gave a second order control model to arc stability stirring current, then designed an arc stability stirring control method based on Fuzzy-PID. The system is a distributed control system consists industrial personal computer, PLC and intelligent instrument based on Profibus-DP and Ethernet. It realizes the automatic detection and control of smelting process. By using the configuration software, we designed and developed a man-machine interfaces system in order to realize displaying of working conditions, displaying and setting of data, process curves, alarm and other functions, which improve the operability of the system.The actual operation and data analysis of arc stability stirring control system for vacuum arc remelting furnace show that this control system played a good role in stable and precise controlling of arc stability current, stirring metal molten pool evenly and has a significant effect to improve crystallization of ingot. It improves VAR system and has promotional value.