Neutral salt spray tests were conducted on assemblies comprising H59 brass and either electrogalvanized or hot-dip galvanized bolts. The polarization curves, electrochemical impedance spectroscopy (EIS), corrosion morphology, elemental distribution, and corrosion product composition of the H59 brass were systematically characterized. The results demonstrated that upon coupling with galvanized bolts, the formation of a protective Cu₂O film on the H59 brass is significantly weakened, leading to accelerated corrosion. After coupling with electrogalvanized bolts, the i_corr reached a maximum value of 0.21 mA/cm². A corrosion layer predominantly composed of ZnO formed on the sample surface with a thickness of approximately 13 μm, and no penetration or enrichment of Cl was observed in the matrix. More seriously, when the brass was assembled with hot-dip galvanized bolts, the i_corr never dropped below 0.2 mA/cm². A porous and complex Zn-Cu-O-Cl mixed corrosion layer developed on its surface. This loose structure allows Cl⁻ to reach a depth of 55 μm into the matrix and continue causing corrosion. The mechanisms underlying the different corrosion behaviors of H59 brass caused by different galvanizing bolt processes require further investigation.

Corrosion failure of transformer terminal connection components poses a severe threat to the service safety of power equipment in coastal regions. This study employs neutral salt spray corrosion testing to simulate the high-temperature summer conditions along Guangzhou’s coastline, investigating the corrosion behaviour of H59 brass transformer wiring clamp. Results indicate that corrosion intensifies under the synergistic effects of galvanic and crevice corrosion when H59 brass is connected to galvanized bolts, with the hot-dip galvanized bolt connection group exhibiting the most severe corrosion. The primary corrosion products of H59 brass in salt spray environments are Cu ₂ O and ZnO. However, following connection with galvanised bolts, the Cu ₂ O phase disappears due to the participation of coating elements in the reaction, with additional oxides such as Sn ₂ O appearing. Compared to the loose ZnO, the ability of H59 brass to form dense Cu ₂ O may be key to its resistance to salt spray corrosion.

The transformer wiring clamps is commonly used for the electrical connection between a transformer’s conductive rod and external conductors. However, it is prone to corrosion in its service environment, which leads to performance degradation and poses potential safety hazards. This study employs COMSOL-based multi-physics simulation to investigate the corrosion behavior of the assembly composed of H59 brass transformer wiring clamps and galvanized Q235 bolts in the atmosphere. It acquires the distribution maps of corrosion potential and current on the surface of the components, which clearly reflect the corrosion susceptibility of different structural parts of the components, and predicts the corrosion depth for 1000 h.