Recent developments in AC square waveform welding

Abstract

The submerged arc welding is a well-established welding technique widely used in fabrication industries because of its higher operational speed and material deposition rate, and better quality with minimum thermal losses, improving productivity. Conventionally used direct current power source in the submerged arc welding process provides more deposition or more penetration when used with negative and positive electrode polarity. Better control of penetration and deposition can be achieved using a square waveform AC power source, wherein the electrode is kept negative for a fraction of a current cycle, known as electrode negative ratio. Square AC provides customized deposition and penetration and reduces the impact of arc blow. The article presents recent developments in the AC square waveform welding. The fundamentals of the process, along with the impact on productivity enhancement, is explained. Subsequently, state-of-the-art and recent developments are presented. The article is expected to act as a guiding document for investigators and the end-users.