In nuclear power, marine engineering, and other fields, a matching system composed of duplex steel and copper alloy is a common combination for rotating components in a seawater environment. However, this system is susceptible to galvanic corrosion that seriously threatens its service safety and service life, with ZCuAl10Fe5Ni5 being the main component corroded. Additionally, current corrosion research on this system has evident gaps. Specifically, the influence of area ratio on galvanic corrosion remains insufficiently understood, and the action mechanism of Cl⁻ on the ZCuAl10Fe5Ni5-based corrosion product film in seawater, as well as the product evolution path, has not been fully revealed, which restricts the development of targeted protection technologies. This study explores the degradation mechanism of ZCuAl10Fe5Ni5 in a specific high-salinity environment (20,000 mg/L Cl⁻), characteristic of nuclear power plant service conditions. The results show that due to the significant electrode potential difference between the SAF2507 duplex steel and ZCuAl10Fe5Ni5 copper alloy, a stable galvanic couple is formed, with ZCuAl10Fe5Ni5 acting as the anode and undergoing dissolution corrosion. When the area ratio of ZCuAl10Fe5Ni5 (anode) to SAF2507 duplex steel (cathode) is 1:50, a significantly stronger galvanic effect is observed. The high concentration of Cl⁻ in seawater can damage the surface of the ZCuAl10Fe5Ni5-based corrosion product film, leading to intensified local corrosion. The ZCuAl10Fe5Ni5-derived corrosion products have a layered structure mainly comprising a mixed system of Cu-Al-Mg oxides/hydroxides, and the corrosion process is accompanied by selective aluminum depletion corrosion. This study provides insight into the corrosion mechanism and key influencing factors of ZCuAl10Fe5Ni5 in the matching system, as well as a theoretical basis and technical support for the design of compatibility metal materials in a seawater environment and the control of corrosion in ZCuAl10Fe5Ni5.

AISI 904L stainless steel (904L SS) is a promising material for nuclear power plant primary circuits due to its superior corrosion resistance, but its corrosion behavior under simulated high-temperature and high-pressure water environments with different microstructures remains poorly understood. In order to systematically investigate and clarify the electrochemical behavior and corrosion behavior under stress of 904L SS with three different microstructures (as-received, sensitized, and solution-treated) in a simulated primary circuit water environment of a nuclear power plant, experiments are conducted using dynamic polarization, electrochemical impedance spectroscopy (EIS), and U-bend immersion methods. The results show that temperature has a significant effect on corrosion resistance. As the temperature increases, the impedance of all microstructures decreases significantly, the passivation zone narrows, and the corrosion current density increases. Under high-temperature and high-pressure conditions, the corrosion resistance of the sensitized samples is the worst, while the samples treated with solution have the best overall performance. That is, microstructural optimization through solution treatment can effectively enhance the high-temperature and high-stress corrosion resistance of 904LSS in the primary circuit water environment.

The development of fusion technology requires materials that can withstand heat, erosion, and activation at the edge of fusion plasma. Thanks to its high melting point, superior thermal conductivity, and excellent resistance to sputtering and retention, tungsten (W) has been regarded as the leading candidate for the plasma-facing materials (PFMs) of the main chambers and divertors in controlled thermonuclear fusion reactors. Nevertheless, W-PFMs are prone to complex severe surface deterioration under extreme service conditions during operation in fusion reactors. This includes physical/chemical sputtering, which results in material loss and plasma contamination; He-induced blistering and fuzz formation, which reduce thermal conductivity by several orders of magnitude; thermal fatigue cracking caused by transient loads; and neutron irradiation embrittlement, which leads to hardening, swelling, and loss of ductility. To overcome these issues while maintaining core thermophysical properties, protective surface layers have been fabricated primarily via chemical vapor deposition (CVD), physical vapor deposition (PVD), and spray and plasma-based surface modification technologies. This review assesses the recent progress in the fabrication of protective surface layers on W for PFM application in fusion reactors from a technical perspective, thereby offering new insights that advance the feasibility of fusion reactors and accelerating the practical realization of sustainable fusion energy systems.

The effect of Nb on the microstructure evolution of the γ′ phase in Co-Ti-V alloys has been studied. The yield strength and ultimate strength of the alloys are measured via compression at 900 °C. This indicates that the alloys with 1% at. Nb present a dual γ and γ′ microstructure. A Co₃V phase exists in 2Nb and 3Nb alloys. The mismatch increases with the increment in Nb content. The yield strength of the alloys rises as the Nb addition increases. After compression at 900 °C, the -type dislocation causes shearing of the γ′ phase in the plane of the base alloy. In the 1Nb alloy, the $<1\overline{1}$0>-type dislocation reacts at the γ/γ′ interface to generate 1/3 super-partial dislocation, and then the γ′ phase is cut by this dislocation and stacking faults are formed.