In response to the problems of performance degradation, sealing failure and medium leakage of metal components in air conditioning pipelines due to material corrosion, this study intends to lay the foundation for exploring the causes of corrosion and optimising anti-corrosion measures in the future, ensuring the safe and stable operation of air conditioning pipelines.

Systematic investigation of corrosion mechanisms and cleaning agent effects was conducted using scanning electron microscopy (SEM), atomic force microscopy, corrosive element detection and cleaning agent immersion tests.

Findings indicate dense corrosion pitting on the tail surface of air conditioning copper tubes (TP2 deoxidised copper), with enriched corrosive Cl and P elements serving as primary corrosion drivers. Under continuous immersion, metal corrosion rates significantly exceed air exposure conditions. Both acidic and alkaline cleaning agents exhibit stronger corrosive effects on carbon steel pressure sections and copper tubes than neutral cleaning agents.

The main factors causing corrosion of TP2 deoxygenated copper pipes in air conditioning, the effects of different environments, and types of cleaning agents on the corrosion of pipeline metals have been identified in the study. It provides reliable theoretical support for the optimisation of anti-corrosion design and scientific selection of cleaning agents for air conditioning pipelines.

There are significant differences in the corrosion protection performance of commonly used cleaning agents for high-speed railways. In order to study the dual requirements of cleaning efficiency and corrosion inhibition, explore the differences in corrosion protection performance of cleaning agents, effectively protect metal substrates, and ensure the safe, economical, and environmentally friendly operation of high-speed railways, this study is hereby carried out.

This study investigated the corrosion behaviour of Q235 steel exposed to acidic, neutral, and alkaline cleaning agents through metallographic analysis, electrochemical testing, and scanning electron microscopy (SEM).

Electrochemical behaviour was assessed at concentrations of 5%, 10%, 15%, and 20% using electrochemical impedance spectroscopy (EIS) and Tafel tests. The results indicate that the protective efficacy of acidic, neutral, and alkaline cleaning agents follows the order: alkaline > neutral > acidic.

Microstructural analysis and energy-dispersive X-ray spectroscopy (EDS) surface element quantification reveal that acidic cleaning agents cause the most severe corrosion and offer the poorest protection for Q235 steel, whereas neutral and alkaline agents provide protective effects by retarding corrosion. Conducting in-depth research on the differences in corrosion protection performance of cleaning agents can effectively safeguard metal substrates, eliminate corrosion risks, and ensure the safe operation of high-speed railways.

– Regarding that Ultraviolet radiation, pollutant adsorption, and environmental changes may be the main reasons for the aging and yellowing on windshield rubber in high-speed trains, countermeasures are proposed to solve the aging and yellowing of windshield rubber and reduce the adverse effects caused by rubber yellowing.

– Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to test the yellowed windshield rubber. Aging tests, including UVaging, natural aging and salt spray aging, were conducted to analyze the effects of aging on the windshield rubber. Different cleaning agents were selected to soak the windshield rubber, and the quality, hardness, and surface appearance of the rubber samples were tested.

– After UV aging, antioxidants migrated to the surface of the windshield rubber, but due to oxidation failure, they could not capture free radicals, leading to continued oxidation reactions within the material and resulting in yellowing of the rubber in a short period of time.

– Cleaning agents have a minimal impact on windshield rubber, UV aging has the greatest impact and natural aging is a gradual and slow deterioration process. Through daily deep cleaning and maintenance with protective agents at regular intervals, the deterioration of windshield rubber yellowing in high-speed trains can be effectively suppressed.

Weathering steel has excellent resistance to atmospheric corrosion, but still faces complex environmental corrosion problems during long-term operation. This paper mainly studies the corrosion problem of weather resistant steel materials for railway freight car bodies with a load capacity of 70 tons.

The paper analyzes the corrosion characteristics of weather resistant steel materials for truck bodies through macroscopic and microscopic methods including metallographic microscopy, scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction. Electrochemical analysis shows that the rust layer on the surface of weathering steel changes the surface state of the material, and also proves that weathering steel used in trucks undergoes electrochemical corrosion under atmospheric corrosion. At the same time, ion chromatography technology is used to study the corrosive ions mainly present in the residual liquid and foam solution inside the vehicle body.

The corrosion of truck body materials is mainly electrochemical corrosion, and the corrosion of door materials is more obvious than that of other parts. The corrosion products are mainly Fe oxides and hydroxides. There arehigh concentrations of Cl– and SO42– ionsin theresidual liquid and foam solutionat thebottom of the freight car, which are the main factors causing corrosion of the railway freight car body.

The foam adhesive around the door panel is in a moist state for a long time, and corrosive ions will accelerate the electrochemical corrosion of the weather resistant steel material of the door panel. Therefore, the corrosion of the cargo door panel is more severe than other components.

As a key structure in the railway power supply system, the overhead catenary pillar carries the entire weight and dynamic load of the contact suspension device and supporting equipment. Its stability and reliability are directly related to the operational safety and efficiency of electrified railways.

Regarding the phenomenon of abnormal shedding of coating above the support under the cantilever of the catenary pillar in the track running line, a three-dimensional model is established to analyse the rigid cantilever type catenary and the force analysis of the cantilever part is carried out by using ABAQUS to calculate the contact force of the bow network under different running speeds of the high-speed train. The load is applied at the locator end of the simplified model of the cantilever to get the support reaction force at the connection between the cantilever and the support.

The support reaction force is applied as a load to the three-dimensional model of the pillar support; the stress cloud and the stress extreme value of 86.14 MPa are obtained for the pillar and the support part and the fatigue life of the pillar’s key parts is calculated to be 12.02 years, respectively.

The upper part of the lower support of the high-speed rail catenary pillar is subjected to the alternating load transmitted by the bow net, which causes the fretting damage at this position, resulting in the abnormal peeling of the coating on the upper part of the lower support. Through combining the ABAQUS analysis with the structural characteristics and operating conditions of the catenary system, the main causes of component failure are determined.