Improvement of corrosion resistance of Ni-based alloy by adding 5 wt.% rhenium

Abstract

In this work, the corrosion behavior and underlying mechanism of Ni-based alloy with the addition of refractory metal rhenium in 3.5 wt% NaCl solution and a high-temperature environment were systematically investigated. After Potentiodynamic polarization and Electrochemical Impedance Spectroscopy tests, it is found that Re can promote the formation of a passivation layer, which reduces the corrosion current density of the alloy by an order of magnitude, and at the same time has a higher impedance arc and shows stronger electrochemical corrosion resistance. Using Energy Dispersive Spectrometer technology to test the samples after high-temperature oxidation, it is found that the uniform distribution of Re will make the alloy form an Nb element rich layer on the surface layer and hinder the diffusion of Mn, making the oxide layer more continuous and dense, thus improving the high-temperature oxidation resistance of the alloy.