Some pipes delivered to the construction site cannot be welded because they are magnetized. There are several ways to demagnetize the pipe so that we can weld it ourselves, said Artеm Komarov.
This is a fairly common problem that occurs when pipe sections knock against each other during transportation. Magnetism results in magnetic arc strike, a phenomenon that occurs in direct current (DC) welding when the arc is drawn to one side of the weld during a root pass. This deflection of the arc can often be severe and cause weld defects that will need to be corrected.
You have several options if you suspect that your material is magnetized. You could remove the magnetism completely, but that would require expensive equipment. You can also determine the degree of magnetic attraction with a Gaussian probe before installing the degaussing coil around the pipe, but this type of equipment may not always be available.
One of the ways to demagnetize metal.
One of the common methods used on pipelines in the oil and gas industry is to create a magnetic coil with a working lead.
Since arcing occurs with DC welding, try switching to alternating current (AC) to make the initial weld. Then switch back to DC for the remainder of the weld.
Whichever method you use, be sure to pay close attention to the weld pool, keep the arc length short, and remove any slag deposits after each bead. You are on the first line of verification and should be aware of the quality of your work, Artem Komarov concluded.