Magnetically Impelled Arc Butt Welding of alloy steel tubes in boilers – Establishment of parameter window

Magnetically Impelled Arc Butt Welding (MIAB) is a hybrid solid-state welding process suitable for butt joining hollow cylindrical sections such as pipes and tubes. This process uses an rotating electric arc for heating the extremes of two tubes, which is impelled due to the electromagnetic force created by the interaction of arc current and magnetic field generated by external magnetic system. This paper presents the attempts made to design and develop a laboratory MIAB welding module operated pneumatically to realize the principle of the process. Trials are conducted with alloy steel tubes (48 mm diameter and 6 mm thickness) by varying the various input parameters and subsequently recording the observations. Based on the basic understanding of the process and its parameters, a pivotal attempt is undertaken to weld alloy steel tubes of boilers with specially made MIAB welding equipment (MD1). Investigations are carried out on MIAB welding machine (MD1) after preliminary experimentation to understand the basic mechanisms involved in MIAB welding process. The experimental procedure involves a series of trials to develop and evaluate the knowledge base for MIAB welding alloy steel tubes. Based on the penetration and bead of the weld (observed through visual inspection), the appropriate ranges of various input process parameters identified are presented.

Research highlights
► The research presented in this paper deals with the employment of MIAB welding for boiler applications. Our group has made the pivotal attempt in the world to do this research and report it in the literature.
► Few of the results of this research have been submitted to ASME for obtaining approval for MIAB welding to be employed for Boilers.
► This research paper deals with confluence of disciplines viz., Electrical, Mechanical, Arc Science, Metallurgy, Physics…….and so on.
► This research aims at fulfilling the prospective of Industrial and Academic concerns.
► The outcome of this research (on MIAB welding) will pave way for reduction of power consumption during welding as compared to the conventional welding processes which is the need of the hour.