Optimization of magnetic arc oscillation system by using double magnetic pole to TIG narrow gap welding

A magnetic arc oscillation system for tungsten inert gas (TIG) narrow gap welding is developed to prevent insufficient sidewall fusion and improve efficiency and quality for thick component welding. The characteristic of the system is that a double magnetic pole is induced by exciting current flowing through the field coil to generate the magnetic field within the welding area. This optimization of double magnetic pole not only enhances magnetic flux density compared with conventional single magnetic pole but also provides reliable melting of the sidewall. In this article, a new experimental method for the determination of the resulting heat input into the workpiece is proposed. Measurements of arc voltage and welding current flowing through the sidewalls are used to validate the redistribution of the arc heat. Furthermore, the difference of linear heat input of the sidewalls caused by current division ratio difference and arc voltage difference was the main reason why the formation characteristics occurred.