Effect of external magnetic field on weld width and reinforcement height of shielded metal arc welded joints

Abstract

Shielded metal arc welding process is one of the most utilized welding processes which are used to join structural components having good mechanical and structural properties. The macro-structure and the mechanical properties of the weld are closely related with each other. The external magnetic field can be applied in such a way that it can spread the molten arc materials. If the external magnetic field is along the direction of welding, the force on the molten electrode material will be normal to the bead direction. If alternative current is used for welding process, the external magnetic field will also be of alternative nature and the arc will be deflected towards both sides of the length of bead. Spreading of molten material increases the weld width and may reduce the reinforcement height. In this work the external magnetic field was produced with the help of a solenoid and the battery eliminator by passing the current through the coils of the solenoid. The heat and the material of arc are distributed to larger area and hence the bead is flattened due to magnetic field. After experimentation it was found that the weld bead width increases and reinforcement height decreases with increase in the value of external parallel magnetic field.