Influence of Chloride Concentration on Fretting Wear Behavior of Inconel 600 Alloy

Abstract

The nickel-based alloy Inconel 600, strengthened by solution treatment, finds extensive application as a heat exchange pipe material in steam generators within nuclear power plants, owing to its exceptional resistance to high-temperature corrosion. However, fretting corrosion occurs at the contact points between the pipe and support frame due to gas–liquid flow, leading to wear damage. This study investigates the fretting wear behavior and damage mechanism of the nickel-based alloy Inconel 600 and 304 stainless steel friction pairs under point contact conditions in a water environment. Characterization was performed using laser confocal scanning microscopy and scanning electron microscopy equipped with energy-dispersive spectroscopy. Results indicate that the friction coefficient remains consistent across different chloride ion concentrations, while the wear volume increases with increasing chloride concentrations. Notably, friction coefficient oscillations are observed in the gross slip regime (GSR). Moreover, the stability of the oxide layer formed in water is compromised, diminishing its protective effect against wear. In the partial slip regime (PSR), friction coefficient oscillations are absent. An oxide layer forms within the wear scar, with significantly fewer cracks compared to those within the oxide layer in the GSR. It is worth noting that in GSR, the friction coefficient oscillates.

Keywords

• steam generators
• Inconel 600
• fretting corrosion
• Cl⁻ concentrations
• fretting wear properties