Weld interface metallurgy of dissimilar alloys welded by TIG technique

Abstract

TIG welding is an important joining technique for fabricating quality structural components with industrial capability. Dissimilar alloy plates were combined using double-sided tungsten inert gas (TIG) welding. Microstructure evaluation of joints were anayzed by using scanning electron microscopy, optical microscope, energy dispersion spectrometry, elemental mapping, electron back scatter diffraction. DSAW technique increased joint penetration and reduced distortion of joints. In the weld metal zone, austenite, delta ferrite and lath martensite were dominant. The weld pool had high density of Cr7C3 and Fe3C phases and low density of CrFe7C0.45, FeNi, martensite, and Fe3Ni2 phases.