EXPERIMENTAL INVESTIGATION OF PFTIG WELDING PROCESS ON 15CDV6 STEEL USING NANOPOWDERS

This study investigates the effect of various nanopowders on PFTIG (Powdered flux Tungsten inert gas) welding of HSLA steel. The High strength low alloy (HSLA) steel identified for this work is 15CDV6 steel. Three different nano-oxide powders such as Cr203, ZnO, and NiO were used in this research. The bead geometry analyzed by using various nanopowders and found that NiO flux has a remarkable effect on penetration and aspect ratio, whereas Cr203 flux was unfavorable in this study. The results indicate that 15CDV6 steel welds pasted with NiO nano flux reduce the risk of solidification cracking susceptibility (SCS). The presence of reversal of Marangoni convection found in the dissolved oxygen concentration results using NiO and ZnO nano fluxes and exceeds the required range of 70 ppm. The arc voltage values using NiO flux pointed to higher heat input, and peak temperatures result in welding arc contraction. The Cr203 nano flux provides a poor bead geometry compared to conventional TIG welding and other powders.