Effect of Aluminizing on the Fatigue and High-Temperature Corrosion Resistance of Inconel 740 Nickel Alloy

Abstract

The fatigue response and high-temperature corrosion resistance of Inconel 740 nickel alloy in its as-received state, and the same material with aluminized surface layer, were investigated. The aluminized layer was applied by using the chemical vapor deposition process with the participation of AlCl3 vapors under a hydrogen protective atmosphere at a temperature of 1040°C for 8 h and internal pressure of 150 hPa. The microstructure of the aluminized layer was characterized through scanning electron microscopy and x-ray energy dispersive spectroscopy analysis. It was found that Inconel 740 with an aluminized surface exhibited an improved hardness and fatigue response of 100 MPa in the whole range of stress amplitudes from 350 MPa to 650 MPa. Additionally, the application of the aluminization process enhanced service life as well as the corrosion resistance of the alloy in question and effectively protected it against high-temperature corrosion.