Gas tungsten arc welding is widely used process in welding industry. In this process filler metal is usually used to make desire welding joint.

Hot wire TIG welding is modified gas tungsten arc welding (GTAW) process in which filler wire is pre-heated before entering into weld pool.

In HW-GTAW process two separate power sources are used, one is to develop arc and another is to heat the filler metal. In HW- TIG filler wire is resistance-heated before entering to weld pool, and the current used to heat the wire is denoted as hot wire current.

HW-GTAW process increases productivity and efficiency of production compared to conventional GTAW process.

In this research of AC/DC hot wire, output has a multi-waveform Hot Wire Current. Using this HW power source, there is a choice of DC output current or AC output current.

In AC mode, user can select multiple options like Frequency, Duty Cycle. Also, user can set different values of current required for wire heating along with different values of frequency and duty cycle.

Initially there is only DC Hot wire was used for GTAW, but there are some limitations to it. To overcome that AC hot wires are introduced. AC tends to aid the process. Its electromagnetic field deflects the welding arc forward and backward in the weld pool, creating a stirring effect.

Using AC HW enhances filler wire deposition rate and also reduces the arc blow problems experienced in DC HW TIG process. AC waveform permits higher feeding speed and current leading to increased deposition rates and welding speed.

This article is shared by Mangesh D. Waman, Arun Kumar Paul and Vijay P. Lotekar from Research & Development, Electronics Devices World Wide Pvt. Ltd