Power Grid Operating Environment Analysis: How Humidity Accelerates The Loss Process Of Bolted Tension Clamps

The long-term stable operation of power transmission and distribution networks is closely related to external natural conditions. Metal fittings exposed to the elements for extended periods are constantly corroded by atmospheric moisture, affecting their mechanical properties and electrical conductivity. Among various environmental factors, atmospheric moisture content is a core variable determining the durability of line hardware.

The Impact of Humidity on the Lifespan of Bolt-Type Tension Clamps: Microscopic Evolution

The effects of high humidity environments on components are mainly reflected in the following dimensions:

• Increased Interface Contact Resistance: Moisture enters the gaps at the bolt fastening points, inducing oxide formation on the contact surface. These non-conductive substances increase the temperature rise of current-carrying components, accelerating material aging.

• Mechanical Strength Decrease: Moisture accumulation triggers intergranular corrosion. Internal stress, under the synergistic effect of the humid medium, may lead to the initiation and propagation of microcracks.

• Thread Locking: Long-term humidity causes rust to form at threaded connections. This irreversible structural damage makes torque verification during subsequent maintenance extremely difficult.

The pathway by which environmental moisture accelerates metal fatigue

When the relative humidity of the air remains in a high range for a long period of time, the zinc coating on the bolted type strain clamp surface will gradually wear away. Once the protective layer loses its effectiveness, the base metal comes into direct contact with oxygen. This rusting process is not limited to the surface but also penetrates into stress-bearing areas. Moisture, acting as an electrolyte, bridges the potential differences between different metals, thus exacerbating electrochemical corrosion. Due to the combined effects of uneven stress and environmental moisture, the material gradually loses its toughness, ultimately shortening its overall service life.

Climatic Conditions Determine Differences in Maintenance Cycles

Maintenance data from coastal or rainforest areas show that high humidity directly shortens the nominal service life of hardware. Compared to dry areas, dead end strain clamp in these regions is more prone to stress concentration-induced fractures. In areas where salt spray and high humidity overlap, the rate of metal peeling increases exponentially.

Observations of samples from different environments revealed that the weather resistance performance of bolted dead end clamp closely matches the humidity curve of its installation environment. This environment-induced loss is often insidious, only becoming apparent when a significant decrease in torque or temperature anomalies occurs. Therefore, in the condition assessment of clamps in areas with high humidity, ambient humidity must be considered as an important parameter for measuring remaining life.