The Physics of the Arc

ABSTRACT

Several researchers have devoted efforts on studying physics of arc and descriptive models are used to explain many arc welding related phenomena. However, due to the subject complexity, doubts still emerge about the mechanisms of some phenomena related to the arc. For instance, the description about electromagnetic interactions with the arc, which governs the arc trajectory and lead to plasma jet and arc blow formation, seems to be yet controversial. Thus, the present study aimed a better understanding of these phenomena. An e-mail survey was carried out to confirm discordant descriptions of the phenomena. Some points were raised about the actual physical explanation used in the current literature. Some experimental work with arcs at different levels of current was developed and shows that plasma jet has an important role in the welding arc trajectory, but there are other factors acting at the same time. Using electromagnetic theory and flow mechanics explanation, more comprehensive models were eventually presented to explain plasma jet formation and the arc blow phenomenon.

Keywords: Plasma jet; Arc blow.

1 INTRODUCTION

Arc welding is one of the most important means of manufacturing. Despite of being widely used, the process correct operation is indispensable to achieve the each day more required quality and productivity. Thus, demands for process improvement appear every day. However, to accomplish with the new applications, a deep knowledge about the concerned phenomena is mandatory for developers. The field of study of these phenomena is known as physics of arc but, unfortunately, due to complexity there are not many specialists in the word dealing with this...

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