Magnetic Coupled Control And Research On Short Circuit Transfer Of CO₂ Gas Shielded Welding

Magnetic control welding is a special type of welding in welding field, magnetic control welding can be applied to a variety of welding methods, such as TIG, MIG, MAG, CO₂, SAW and LBW, almost all of the welding methods. When magnetic control welding, adds the action of electromagnetic forces, welding arc and metal transfer will be changed, such as the arc shape, droplet form and so on.CO₂ gas shielded welding is an economical and efficient method of welding. It has a lot of advantages, but the larger spatter and bad performance of seam are the two critical problems of CO₂ gas shielded welding process. So this paper is committed to explore a new kind of equipment and method to control droplet transfer. External coupled magnetic field on droplet short circuit transfer process of CO₂ gas shielded welding will cause a stable short circuit transfer process with much lower spatter and better performance of seam.This paper includes the development of coupled magnetic control equipment, designing of magnetic head, studding on the experiment CO₂ gas shielded welding under the control of coupled magnetic field. Coupled control circuit was devised in the equipment to detect the short circuit transfer process in CO₂ gas shielded welding, while the output magnetic field is coupled with the welding process to promote droplet transfer. This equipment has the advantage of small size, light weight, high control precision, easy to use and so on. The magnetic head was designed with anti-high temperature, insulation seals, anti-jamming capabilities. It is found that spatter rate was significantly changed under the same welding parameters but different magnetic field controlled. The results showed that, spatter rate without magnetic field controlled is: 6.12%, spatter rate of non-coupled magnetic field controlled is: 4.98%, and spatter rate of coupled magnetic field controlled is: 3.14%. Under the effect of coupled magnetic field, spatter decrease of 48.7%. Test results indicated that welding under coupled magnetic field controlled can significantly reduce spatter rates of CO₂ gas shielded welding. This paper also use equipment such as Oscilloscopes, Labview instrument to test for comparison and analysis. It is found that droplet transition frequency will increase and more stable under the control of coupled magnetic field.