Effect of Frequency on Microstructural and Corrosion Demeanour of Alloy C-276 Weldment

This research work describes the effect of varying frequency of pulsed current gas tungsten arc welding (PCGTAW) on alloy C-276. Investigations were carried out to evaluate the consequence of varying frequency (Hz) on the microstructural and corrosion demeanour of alloy C-276 weldment. Bead-on-weld trials was carried out by varying the frequency from 1 to 10 Hz and keeping other process parameters as constant. The microstructural property of the bead on weld is studied through optical and scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Corrosion behaviour studies were carried in synthetic seawater condition. Micro-examinationreveals the presence of equiaxed dendritic structure on all the trials of the bead on the weld. The absence of secondary phase was observed through scanning electron microscope (SEM). From the EDS analysis, the absence of micro segregation can be observed for all the weldments. Corrosion rate increase as the frequency (1 to 10 Hz) of the weldment increase. It is inferred from the results that as frequency increase from 1 to 10 Hz, refining of grain takes place with an increase in the corrosion rate. (C) 2019 Elsevier Ltd. All rights reserved.