Abstract
Arc behavior of Rotating Arc Butt Welding were studied in order to extend the applicable pipe diameter and thickness ranges. Experiments were carried out for 216.3 mm O.D×5.8 mm wall steel pipes by using design of experiment in which gap, arc current and exciting current were selected as important experimental factors. Main results are summarized as follows;
(1) Arc rotating frequency is mainly affected by gap of pipes and arc rotating smoothness at the early stage of welding is affected by exciting current.
(2) The period of melting process and arc rotating process is influenced by arc current.
(3) Characteristic phenomena are observed by high speed photograph, such as showerlike spatter, small grain spatter, plural arc and dripping molten metal.
(4) It was observed much small grain spatters were dispersed at the small gap than large gap of pipes. The good quality of welded joint was not obtained at small gap condition.
