Background

A 220 kV overhead transmission line located along the southeastern coast suffered severe ACSR conductor corrosion after 6 years of service. High salt spray, high humidity, and periodic typhoons caused rapid steel‑core rusting, aluminum strand pitting, and inter‑strand contact degradation. Routine inspections revealed localized corrosion and increased risk of broken strands.

Solution

The utility selected a heavy‑duty polyisobutylene‑based anti‑corrosion grease compliant with GB/T 36292 and IEC 61394. The grease featured high dropping point (>180 °C), low oil separation, and excellent salt‑water resistance. The full treatment included:

• Thorough cleaning and drying of conductor surfaces
• Full‑cross‑section grease infusion into inter‑strand gaps
• External coating to seal out moisture and salt ions
• Key focus on corrosion prevention at suspension clamps and dead‑ends

Outcomes

• Steel core corrosion rate reduced by 90%
• Aluminum strand pitting and rust eliminated
• Service life extended by 12+ years
• Line maintenance frequency cut by 70%
• No hydrogen‑assisted cracking or broken strands observed in 5‑year follow‑up inspections

Conclusion

Anti‑corrosion grease effectively blocks salt‑fog penetration and electrochemical corrosion, making it a cost‑effective long‑term protection solution for coastal transmission lines.