Magnetic Rotating Arc Welding

Developed in the 1970's, magnetic rotating arc welding is also known as magnetarc welding or magnetically impelled arc butt (MIAB) welding . It is defined as "an arc welding process in which an arc is created between the butted ends of tubes and propelled around the weld joint by a magnetic field, followed by an upsetting operation." The procedure is a mixture of arc and forge welding with a gas shielding operation added on. This method of welding by clamping the parts to be joined into the machine. Next, the two pieces are pushed together and electricity is applied to them. As they are separated, an arc is started. When the arc is established, a magnetic coil around the weld repels the arc, which pushes it around the perimeter of the piece. The arc runs around the piece at a speed close to 50 meters a second. At this speed the arc looks as though it is a circle of light between the pieces. After the arc has run around the piece for a determined amount of time, the two pieces are pressed together to join them .

This process is now very popular in mass production situations. The entire system is fast, can be automated, and requires less energy than other types of welding. The parts do not need to be cylindrical and the welds are repeatable with high quality and little deformities. Also, this welding does not expel as much metal as does other forms of welding, which makes MIAB welding more efficient. The drawback comes from the fact that the arc only heats the edges of the pieces, not the middle. This means that only a certain thickness of metal can be welded in this fashion and that solid pieces of metal cannot be joined.