Electrochemical behavior of friction stir welded joint of ultra-low carbon steel

Abstract

Abstract In this study, friction stir welding of ultra low carbon steel was performed at tool rotational speeds in the range from 300 to 750rpm with 150rpm increments at 60mm/min fixed traverse speed. Throughout study was performed on macro and micro structures in order to determine the several welded zones for example stir zone, thermo-mechanically affected zone, and heat-affected zone. Microhardness profiles were performed along the welded joint's cross section and the utmost hardness was obtained at stir or nugget zone as compared to the other zones of the welded joints. The hardness values on the stir zone decreases with rise in tool rotating speed. Electrochemical study was investigated in 3.5%NaCl electrolyte solution. Corrosion rate is maximum (~27MPY) at 300 rpm stir zone and minimum value (~0.3 MPY) obtained at heat affected zone at 750rpm welded sample.