Effect of oxidation film on the fretting wear behavior of Alloy 690 steam generator tube mated with SUS 409

Effect of formation of oxidation film on the wear behavior of Alloy 690 steam generator (SG) tubes for nuclear power plants was investigated. Alloy 690 SG tubes are normally oxidized during operation due to the high temperature of the pressurized water. Based on the previous tribology research for metallic materials, we reasoned that the oxidation film can have an important effect on the wear behavior of the Alloy 690 SG tubes. Therefore, in this study, Alloy 690, oxidized in an autoclave under secondary water conditions, was used for wear test. The result of the wear test showed that as the oxidation treatment time increased, the thickness of oxidation film increased and the wear resistance of Alloy 690 increased. •Cr2o3 and NiFe2O4 spinel oxide is formed on Alloy 690 during oxidation treatment.•Oxide thickness increased rapidly until 100h and increased linearly until 2000h.•Oxidation film prevents metal to metal contact and material transfer during sliding wear test.•Formation of disturbed layers is hindered by preventing metal to metal contact.•Wear resistance of Alloy 690 increased with increasing oxide thickness.