5次循環(huán)以內，690 TT合金的磨損機制主要為伴隨材料轉移的粘著磨損；5×105至2×106次循環(huán)下，690 TT合金的磨損機制主要為裂紋萌生、擴展和分層脫落。微觀組織演變方面，105次循環(huán)的樣品截面微觀形貌中，三體層下存在混合層；5×105和2×106次循環(huán)的樣品截面微觀形貌區(qū)別不大，具有厚度約為500 nm的摩擦轉化結構層，微觀組織演變進入穩(wěn)定階段。;The service water environment of high temperature and high pressure was simulated for the steam generator heat transfer tube of pressurized water reactor. 690 TT alloy tube and 405 SS plate were used to form the friction pair for impact slip dual-axis fretting corrosion experiments. The microstructure evolution of 690 TT alloy tube during dual-axis impact slip fretting corrosion was investigated. White light interferometer, scanning electron microscope, transmission electron microscope, and Raman spectrum were used to investigate the microstructure and abrasive products of the abraded surface and near-surface. Results indicate that within 105 cycles, the wear mechanism of 690 TT alloy tube is mainly adhesive wear accompanied by material transfer. With the increase in cycles from 5×105 to 2×106, the wear mechanism of 690 TT alloy tube is mainly crack initiation, propagation, and delamination. In terms of microstructure evolution, mixed layer exists under the three body layer in the cross-section microstructure of samples after 105 cycles. The microstructures of samples after 5×105 and 2×106 cycles show slight difference and present a tribological transfer structure layer with thickness of about 500 nm. Additionally, the microstructure evolution enters the stable stage."/>