Thin sheets of UNS R30155 alloy with a thickness of 0.6 mm with AMS 5832 filler metal were welded using gas tungsten arc welding (GTAW). The aim of this project was to study the effect of frequency on the microstructure and mechanical properties and hot corrosion of the joints. The microstructure, chemical composition and fracture surfaces were examined by optical microscopy (OM) and scanning electron microscopy (SEM) equipped with energy dispersive x-ray spectroscopy (EDS) and EBSD. Microhardness, tensile and shear punch tests were used to study the mechanical properties. The results of the tests indicated that increasing the frequency up to the optimal level expands the region of fine equiaxed grains that contains equiaxed dendrites, it can limit the growth of epitaxial grains by crushing dendritic arms and producing solid particles as modifiers, and it increases the zone of equiaxed grains with random directions and finally, the texture intensity of the weld metal is reduced in the direction of easy growth 001 ?ND, resulting in an increase in the elongation, micro-hardness, tensile and shear strengths. Increasing the frequency causes uniform distribution of alloying elements in the weld metal, and increasing it more than the optimal level causes heterogeneity in the chemical composition and the formation of dispersed islands of equiaxed dendrites in the weld metal. Using non-pulsed current with higher heat input, the epitaxial grains grow widely and maintain texture intensity in the direction of easy growth, which weakens the mechanical properties. Weld metal of the sample with optimal frequency has uniform chemical composition, when this sample is involved with hot corrosion phenomenon of Na 2 SO 4 Salt, it can give a smooth surface of the metal-skin interface, that in other welding specimens, the metal surface is unevenly corroded due to the formation of poor and rich areas of key elements of chromium and nickel due to the segregation of the elements from welding solidification. According to the hot corrosion results of the specimens, using of AMS 5832 filler metal is ideal choice in the welding of UNS R30155 alloy because hot corrosion resistance of the weld metal of the samples is much more than the base metal.