Feasibility of Magnetically Impelled Arc Butt (MIAB) Welding of High-Thickness Tubes for Pressure Parts

Abstract

Magnetically impelled arc butt (MIAB) welding is a solid phase pressure welding process similar to flash-butt welding, but it uses a magnetic field to rapidly spin the arc. The spinning arc provides a more consistent interior and exterior weld flash than typically seen on the flash-butt upset areas. MIAB welding process is presently being employed for welding tubular sections in automobile industries in various parts of United Kingdom and Germany. However, there are no details reported in available literatures on application of MIAB welding process for pressure parts. Hence, in this study, a pivotal attempt is being made to employ MIAB welding process to weld carbon steel tubes (51 mm and 44 mm outer diameter) and (5-6 mm thick) in economizer coils of pressure vessel. Several trials are conducted to create an optimal parameter window for MIAB welding process by varying the different input parameters. Further, mechanical testing and metallurgical characterization are carried out on the MIAB-welded specimen to evaluate its strength and to assess the weld integrity. The results of the experiment emphasized that the MIAB-welded joints exhibited high strength and good weld integrity.