Experimental study on mechanical, damping and corrosion properties of Inconel 718 hard-faced stainless steel 304 using cold metal transfer

Abstract

Cold Metal Transfer process is used to hard-face the Inconel 718 alloy onto the Stainless Steel 304 material. The optimized parameters from the Bead on Plate trials were determined as a wire feed rate of 7 m/min, deposition speed of 15 cm/min, welding current, and voltage of 175 A and 14.9 V, respectively. Hard-facing is carried out with the sinewave weaving technique along 30 % of overlapping beads. The analysis is focused on revealing the hard-faced specimens' microstructural, mechanical, and electrochemical corrosion properties. The hard-face layer exhibits grains of mixed modes, including columnar, cellular, and fine equiaxed grains. The increased heat transfer disintegrates grain formation and reduces secondary arm spacing development. SEM-Elemental mapping shows the reduction of Niobium (3.61 %) segregation and laves formation. The overlay layer has a maximum hardness of 343.1 HV0.5 over the base substrate with 204 HV0.5. The impact test reveals the hard-faced layer absorbs more energy (26.3 %) than the substrate. Dynamic Mechanical Analysis results indicate overlay layer enhancing damping properties. The electrochemical corrosion test findings suggest that the hard-faced layer's high corrosion potential (Ecorr = 8.533 mV) corresponds to a high corrosion resistance. Phase and intermetallic formations, distribution of elements, fractured and corrosive surface morphologies are analyzed using SEM, EDX, and elemental mapping results.