Automatic Temperature Control System for Electric Resistance Annealing of Steel Welding Wire

A direct electric resistance heating has been shown to be a preferable method capable of directly achieving the specified properties of the wire during annealing, as well as enabling an improved controllability of the annealing process by utilizing process automation, and providing flexibility of the industrial systems. To estimate energy consumption, temperature fields were calculated during the drawing process under different heating conditions. In addition, temperature measurements were conducted and experimental data treatment was performed for an indirect heating using a continuous furnace and electric-current heating. It was shown that in the process of drawing with the use of a pulsed current, an electroplastic effect (EPE) is created in the deformation zone. The described mathematical model was used to obtain the temperature distribution in the heating zone of the wire exposed to a pulsed current, the nature of which causes the EPE occurrence. The EPE significantly reduces power consumption and operating voltage applied to the workpiece, while ensuring that the specified parameters of the wire are obtained when higher values of current are used. A pilot installation for performing electric resistance annealing (ERA) was designed and implemented. The main purpose of the implemented installation for annealing steel wire was to create a system of electrically conductive rollers used to supply electric current directly to the heating zone. Such system represents a robust stand-alone link in the wire heating process and allows for a trouble-free installation at any transporting section of the heated element (annealed material). The use of an automated control system with temperature and control current feedback for wire annealing ensures a stable operation of the entire system. The use of the experimental installation made it possible to achieve an 18% increase in the annealing rate for a 100 kg wire coil. An automated control system was used to control the drawing process and ensure uniform physical and mechanical properties of the resulting wire when using the electroplastic effect. As a result, the experimental data were obtained, the treatment of which made it possible to draw conclusions and make recommendations regarding a commercial implementation of such installations into the manufacturing process.