Effects of high-temperature and high-pressure immersion corrosion durations on the fretting tribo-corrosion behaviors of Inconel 690 alloy

Abstract

An Inconel 690 alloy tube acting as a steam generator tube has been widely applied in the second and third generations of nuclear power plants using pressurized water reactors. However, its entire service process is always accompanied by high-temperature and high-pressure (HTHP) liquid medium corrosion and various fretting mechanical damage behaviors. This study first immerses the Inconel 690 alloy tube in HTHP corrosive medium for different lengths of time (0, 4, 8, and 12 h); then, a fretting tribo-corrosion test rig is used to investigate the effect of different fretting mechanical parameters on the surface damage mechanism and electrochemical dynamic response of each test sample. Results show that the corrosion rate of the Inconel 690 alloy tube has significantly increased after being treated by HTHP immersion corrosion, which is mainly due to the pre-existing corrosion products.