Study on the Fretting Wear Behavior and Mechanism of Nuclear Alloy 690 Tube

The fretting wear behavior of Inconel 690 for steam generator tube in a nuclear power plant against Inconel 600 (Cr plating) for anti-vibration bar was investigated in a plain cylinder/plane contact configuration under ambient conditions. The fretting wear tests were conducted under various applied normal loads of 20-100 N, slip amplitudes of 20-100 μm and frequency of 2 Hz. Observation of worn surface and corresponding chemical composition analysis were performed to clarify the fretting wear mechanism. It is found that the friction coefficient value increases firstly and then tends to stabilize with decrease in normal loads and increase in slip amplitudes. In addition, the fretting regime is identified to be gross slip regime, indicating that the fretting damage mechanism of Inconel 690 tube against Inconel 600 (Cr plating) bar is wear. The corresponding fretting wear mechanisms are dominant by delamination wear, abrasive wear and friction oxidation.