A system for negating remnant magnetic fields in a weld joint between two workpieces includes a controller and an electromagnet with two feet that form the pole pieces. The electromagnet feet are formed with surfaces that provide a substantial area for magnetic flux coupling with each workpiece on either...http://www.google.ca/patents/US5345058?utm_source=gb-gplus-sharePatent US5345058 - Magnetic field negating system for weldments
