Study of Mechanical Behavious and Characterization of a Steel Joints in MIG Welding under Varying Fluxes

Abstract

A lot of research work has been carried out varying welding parameters and studying its effects but rare work has been done on application of fluxes in MIG welding. Two different FeO based fluxes; Nano-flux and easy- flo flux powder were applied to the joints of 10 pcs each of 50 x 50 mm stainless and mild steel rods, galvanized and mild steel plates using MIG welding process. The samples used were welded under three categories; includes without flux (control), with nano-flux and easy-flow type-flux powder. The weld of the joints were subjected to mechanical test; hardness, tensile and morphological test; SEM and TEM examinations. The weld joints produced using the fluxes were found to have higher average values of hardness and tensile (stress and strain) of 222.73 BHN, 0.03125 and 199.97 BHN, 0.02785 respectively compare to samples without flux having lowest value of 131.36 BHN, 0.01323. The Microstructural analysis results with the use of SEM and TEM were found to have a better ordered grain structure and improved the structure, surface and pattern of the weld than those produced without flux.. The results obtained has revealed the impact of flux in MIG welding for joining steel gave better joint hardness and the structure of the weld.