Development of Hot Wire TIG Welding Methods Using Pulsed Current to Heat Filler Wire

—Research on Pulse Heated Hot Wire TIG Welding Processes (Report 1)—

Abstract

First, five items are mentioned as the main problems that have complicated the workability of hot wire TIG welding. In this paper, it is shown that two fundamental items in the problems have been examined and their countermeasures have been established.
Regarding the problem of magnetic arc blow by the wire current, it is effective to use a pulsed current for wire heating. It is possible to reduce the influence of magnetic arc blow by keeping a sufficient non-pulse period of the wire current because the arc is not blown during the non-pulse period.
Regarding the problem of arcing from the hot wire, a countermeasure in which the wire current is not supplied when the wire tip is detached from the base metal has been established. From the wire voltage during the non-pulse period of the wire current, it can be easily detected whether the wire tip is separated from the base metal.
The application of these developed technologies makes it practical to perform semi-automatic TIG welding with a hot wire torch and an arc torch in each hand.