Magnetic hysteresis loop behaviour of welded ferritic stainless steel 409L with the variation of magnetic field intensity

Hysteresis loop analysis technique, being a non-destructive testing technique is more beneficial than the destructive testing techniques to characterise the welded plate. In this study, the ferritic stainless steel AISI 409L plate was butt welded by gas metal arc welding process. Hysteresis loop analysis technique was used to study the microstructures and microhardness of the base metal region, heat affected zone and weldmetal zone. This study has been carried out at four different values of magnetic field intensity 250, 500, 750 and 1000 Oe. The effect of variation of magnetic field intensity on the hysteresis loop characteristics (average maximum flux density and core loss) has been investigated for base metal, heat affected zone and weldmetal zone. It was found that for each region, the average maximum flux density as well as core loss increases on increasing magnetic field intensity. Also, the variation of average maximum flux density is inversely proportional to the microhardness of the region at each value of magnetic field intensity.